Special Report on Diseases of the Horse (part 2 of 4)

Special Report on Diseases of the Horse (part 2 of 4)

Inflammation may attack these membranes singly, or any one of the anatomical divisions of the nerve matter, or it may invade the whole at once. Practical experience, however, teaches us that primary inflammation of the dura mater is of rare occurrence, except in direct mechanical injuries to the head or diseases of the bones of the cranium. Neither is the arachnoid often affected with acute inflammation, except as a secondary result. The pia mater is most commonly the seat of inflammation, acute and subacute, but from its intimate relation with the surface of the brain the latter very soon becomes involved in the morbid changes. Practically, we can not separate inflammation of the pia mater from that of the brain proper. Inflammation may, however, exist in the center of the great nerve masses--the cerebrum, cerebellum, pons Varolii, or medulla at the base of the brain--without involving the surface. When, therefore, inflammation invades the brain and its enveloping membranes it is properly called encephalitis; when the membranes alone are affected it is called meningitis, or the brain substance alone cerebritis. Since all the conditions merge into one another and can scarcely be recognized separately during the life of the animal, they may here be considered together.

Causes.--Exposure to extreme heat or cold, sudden and extreme changes of temperature, excessive continued cerebral excitement, too much nitrogenous feed, direct injuries to the brain, such as concussion, or from fracture of the cranium, overexertion, sometimes as sequelae to influenza, pyemia, poisons having a direct influence upon the encephalic mass, extension of inflammation from neighboring structures, food poisoning, tumors, parasites, metastatic abscesses, etc.

Symptoms.--The diseases here grouped together are accompanied with a variety of symptoms, almost none of which, however, are associated so definitely with a special pathological process as to point unmistakably to a given lesion. Usually the first symptoms indicate mental excitement, and are followed by symptoms indicating depression. Acute encephalitis may be ushered in by an increased sensibility to noises, with more or less nervous excitability, contraction of the pupils of the eyes, and a quick, hard pulse. In very acute attacks these symptoms, however, are not always noted. This condition will soon be followed by muscular twitchings, convulsive or spasmodic movements, eyes wide open with shortness of sight. The animal becomes afraid to have his head handled. Convulsions and delirium will develop, with inability of muscular control, or stupor and coma may supervene. When the membranes are greatly implicated, convulsions and delirium with violence may be expected, but if the brain substances are principally affected stupor and coma will be the prominent symptoms. In the former condition the pulse will be quick and hard; in the latter, soft and depressed, with often a dilatation of the pupils, and deep, slow, stertorous breathing. The symptoms may follow one another in rapid succession, and the disease approach a fatal termination within 12 hours. In subacute attacks the symptoms are better defined, and the animal seldom dies before the third day. Within three or four days gradual improvement may become manifest, or cerebral softening with partial paralysis may occur. In all cases of encephalitis there is a marked rise in temperature from the very onset of the disease, with a tendency to increase until the most alarming symptoms develop, succeeded by a decrease when coma becomes manifest. The violence and character of the symptoms greatly depend upon the extent and location of the structures involved. Thus, in some cases there may be marked paralysis of certain muscles, while in others there may be spasmodic rigidity of muscles in a certain region. Very rarely the animal becomes extremely violent early in the attack, and by rearing up, striking with the fore feet, or falling over, may do himself great injury. Usually, however, the animal maintains the standing position, propping himself against the manger or wall, until he falls from inability of muscular control, or from unconsciousness. Occasionally, in his delirium, he may go through a series of automatic movements, such as trotting or walking, and, if loose in a stall, will move around persistently in a circle. Early and persistent constipation of the bowels is a marked symptom in nearly all acute affections of the brain; retention of the urine, also, is frequently observed.

Following these symptoms there are depression, loss of power and consciousness, lack of ability or desire to move, and usually fall of temperature. At this stage the horse stands with legs propped, the head hanging or resting on the manger, the eyes partly closed, and does not respond when spoken to or when struck with a whip.

Chronic encephalitis or meningitis may succeed the acute stage, or may be due to stable miasma, blood poison, narcotism, lead poisoning, etc. This form may not be characterized in its initial stages by excitability, quick and hard pulse, and high fever. The animal usually appears at first stupid; eats slowly; the pupil of the eye does not respond to light quickly; the animal often throws his head up or shakes it as if suffering sudden twinges of pain. He is slow and sluggish in his movements, or there may be partial paralysis of one limb, one side of the face, neck, or body. These symptoms, with some variations, may be present for several days and then subside, or the disease may pass into the acute stage and terminate fatally. Chronic encephalitis may effect an animal for ten days or two weeks without much variation in the symptoms before the crisis is reached. If improvement commences, the symptoms usually disappear in the reverse order to that in which they developed, with the exception of the paralytic effects, which remain intractable or permanent. Paralysis of certain sets of muscles is a very common result of chronic, subacute, and acute encephalitis, and is due to softening of the brain or to exudation into the cavities of the brain or arachnoid space.

Softening and abscess of the brain are terminations of cerebritis. It may also be due to an insufficient supply of blood as a result of diseased cerebral arteries and of apoplexy. The symptoms are drowsiness, vertigo, or attacks of giddiness, increased timidity, or fear of familiar objects, paralysis of one limb, hemiplegia, imperfect control of the limbs, and usually a weak, intermittent pulse. In some cases the symptoms are analogous to those of apoplexy. The character of the symptoms depends upon the seat of the softening or abscess within the brain.

Cerebral sclerosis sometimes follows inflammation in the structure of the brain affecting the connective tissues, which eventually become hypertrophied and press upon nerve cells and fibers, causing their ultimate disappearance, leaving the parts hard and indurated. This condition gives rise to a progressive paralysis and may extend along a certain bundle of fibers into the spinal cord. Complete paralysis almost invariably supervenes and causes death.

Lesions.--On making post-mortem examinations of horses which have died in the first stages of either of these diseases we find an excessive engorgement of the capillaries and small blood vessels, with correspondingly increased redness and changes in both the contents and the walls of the vessels. If death has occurred at a later period of the disease, it will be found that, in addition to the redness and engorgement, an exudation of the contents of the blood vessels into the tissues and upon the surfaces of the inflamed parts has supervened. If the case has been one of encephalitis, there will usually be found more or less watery fluid in the ventricles (natural cavities in the brain), in the subarachnoid space, and a serous exudation between the convolutions and interstitial spaces of the gray matter under the membranes of the brain. The quantity of fluid varies in different cases. Exudations of a membranous character may be present, and are found attached to the surfaces of the pia mater.

In meningitis, especially in chronic cases, in addition to the serous effusion, there are changes which may be regarded as characteristic in the formation of a delicate and highly vascular layer or layers of membrane or organized structure on the surface of the dura mater, and also indications of hemorrhages in connection with the membranous formations. Hematoma, or blood tumors, may be found embedded in this membrane. In some cases the hemorrhages are copious, causing paralysis or apoplexy, followed by speedy death. The meningitis may be suppurative. In this case a puslike exudate is found between the membranes covering the brain.

In cerebritis, or inflammation of the interior of the brain, there is a tendency to softening and suppuration and the formation of abscesses. In some cases the abscesses are small and numerous, surrounded with a softened condition of the brain matter, and sometimes we may find one large abscess. In cases of recent development the walls of the abscesses are fringed and ragged and have no lining membrane. In older or chronic cases the walls of the abscesses are generally lined with a strong membrane, often having the appearance of a sac or cyst, and the contents have a very offensive odor.

Treatment.--In all acute attacks of inflammation involving the membranes or cerebral masses, it is the pressure from the distended and engorged blood vessels and the rapid accumulation of inflammatory products that endangers the life of the animal in even the very early stage of the disease. The earlier the treatment is commenced to lessen the danger of fatal pressure from the engorged blood vessels, the less effusion and smaller number of inflammatory products we have to contend with later. The leading object, then, to be accomplished in the treatment of the first stage of encephalitis, meningitis, or cerebritis, and before a dangerous degree of effusion or exudation has taken place, is to relieve the engorgement of the blood vessels and thereby lessen the irritation or excitability of the affected structures. If the attempt to relieve the engorgement in the first stage has been only partially successful, and the second stage, with its inflammatory products and exudations, whether serous or plastic, has set in, then the main objects in further treatment are to keep up the strength of the animal and hasten the absorption of the exudative products as much as possible. To obtain these results, when the animal is found in the initial stage of the disease, if there is unnatural excitability or stupor with increase of temperature and quickened pulse, we should apply cold to the head in the form of cold water or ice. For this purpose cloths or bags may be used, and they should be renewed as often as necessary. If the disease is still in its early stages and the animal is strong, bleeding from the jugular vein may be beneficial. Good results are to be expected only during the stage of excitement, while there is a strong, full pulse and the mucous membranes of the head are red from a plentiful supply of blood. The finger should be kept on the pulse and the blood allowed to flow until there is distinct softening of the pulse. As soon as the animal recovers somewhat from the shock of the bleeding the following medicine should be made into a ball or dissolved in a pint of warm water and be given at one dose: Barbados aloes, 7 drams; calomel, 2 drams; powdered ginger, 1 dram; tincture of aconite, 20 drops.

The animal should be placed in a cool, dark place, as free from noise as possible. When the animal becomes thirsty half an ounce of bromid of potash may be dissolved in the drinking water every six hours. Injections of warm water into the rectum may facilitate the action of the purgative. Norwood's tincture of veratrum viride, in 20-drop doses, should be given every hour and 1 dram of solid extract of belladonna every four hours until the symptoms become modified and the pulse regular and full.

If this treatment fails to give relief, the disease will pass into the advanced stages, or, if the animal has been neglected in the early stages, the treatment must be supplanted with the hypodermic injection of ergotin, in 5-grain doses, dissolved in 1 dram of water, every six hours. The limbs may be poulticed above the fetlocks with mustard. Warm blanketing, to promote perspiration, is to be observed always when there is no excessive perspiration.

If the disease becomes chronic (encephalitis or meningitis), we must place our reliance upon alteratives and tonics, with such incidental treatment as special symptoms may demand. Iodid of potassium in 2-dram doses should be given three times a day and 1 dram of calomel once a day to induce absorption of effusions or thickened membranes. Tonics, in the form of iodid of iron in 1-dram doses, to which is added 2 drams of powdered hydrastis, may also be given every six or eight hours, as soon as the active fever has abated. After the disappearance of the acute symptoms, blisters (cantharides ointment) may be applied behind the poll. When paralytic effects remain after the disappearance of all other symptoms, sulphate of strychnia in 2-grain doses, in combination with the other tonics, may be given twice a day and be continued until it produces muscular twitching. In some cases of paralysis, as of the lips or throat, benefit may be derived from the moderate use of the electric battery. Many of the recoveries will, however, under the most active and early treatment, be but partial, and in all cases the animals become predisposed to subsequent attacks. A long time should be allowed to pass before the animal is exposed to severe work or great heat. When the disease depends upon mechanical injuries, they have to be treated and all causes of irritation to the brain removed. If it is due to stable miasma, uremic poisoning, pyemia, influenza, rheumatism, toxic agents, etc., they should receive prompt attention for their removal or mitigation.

Cerebral softening, abscess, and sclerosis are practically inaccessible to treatment, otherwise than such relief as may be afforded by the administration of opiates and general tonics, and, in fact, the diagnosis is largely presumptive.

CONGESTION OF THE BRAIN, OR MEGRIMS.

Congestion of the brain consists in an accumulation of blood in the vessels, also called hyperemia, or engorgement. It may be active or passive--active when there is an undue accumulation of blood or diminished arterial resistance, and passive when it accumulates in the vessels of the brain, owing to some obstacle to its return by the veins.

Causes.--Active cerebral congestion may be from hypertrophy of the left ventricle of the heart, excessive exertion, the influence of extreme heat, sudden and great excitement, artificial stimulants, etc. Passive congestion may be produced by any mechanical obstruction which prevents the proper return of blood through the veins to the heart, such as a small or ill-fitting collar, which often impedes the blood current, tumors or abscesses pressing on the vein in its course, and organic lesions of the heart with regurgitation.

Extremely fat animals with short, thick necks are peculiarly subject to attacks of cerebral congestion. Simple congestion, however, is merely a functional affection, and in a slight or moderate degree involves no immediate danger. Extreme engorgement, on the contrary, may be followed by rupture of previously weakened arteries and capillaries and cause immediate death, designated then as a stroke of apoplexy.

Symptoms.--Congestion of the brain is usually sudden in its manifestation and of short duration. The animal may stop very suddenly and shake its head or stand quietly braced, then stagger, make a plunge, and fall. The eyes are staring, breathing hurried and stertorous, and the nostrils widely dilated. This may be followed by coma, violent convulsive movements, and death. Generally, however, the animal gains relief in a short time, but may remain weak and giddy for several days. If it is due to organic change of the heart or the disease of the blood vessels in the brain, then the symptoms may be of slow development, manifested by drowsiness, dimness or imperfect vision, difficulty in voluntary movements, diminished sensibility of the skin, loss of consciousness, delirium, and death. In milder cases effusion may take place in the arachnoid spaces and ventricles of the brain, followed by paralysis and other complications.

Pathology.--In congestion of the brain the cerebral vessels are loaded with blood, the venous sinuses distended to an extreme degree, and the pressure exerted upon the brain constitutes actual compression, giving rise to the symptoms just mentioned. On post-mortem examinations this engorgement is found universal throughout the brain and its membranes, which serves to distinguish it from inflammations of these structures, in which the engorgements are confined more or less to circumscribed portions. A prolonged congestion may, however, lead to active inflammation, and in that case we find serous and plastic exudations in the cavities of the brain. In addition to the intensely engorged condition of the vessels we find the gray matter of the brain redder than natural. In cases in which several attacks have occurred the blood vessels are often found permanently dilated.

Treatment.--The animal should be taken out of harness at once, with prompt removal of all mechanical obstructions to the circulation. If it is caused by venous obstruction by too tight a collar, the loosening of the collar will give immediate relief. The horse should be bled freely from the jugular vein. If due to tumors or abscesses, a surgical operation becomes necessary to afford relief. To revive the animal if it becomes partially or totally unconscious, cold water should be dashed on the head. Give a purge of Glauber's salt. If the limbs are cold, tincture of capsicum or strong mustard water should be applied to them. If symptoms of paralysis remain after two or three days, an active cathartic and iodid of potassium will be indicated, to be given as prescribed for inflammation of the brain. In confirmed cases, treatment is not advisable, as there is considerable danger to the owner should an attack occur in a crowded street.

Prevention.--Well-adjusted collar, with strap running from the collar to the girth, to hold down the collar when pulling upgrade; regular feed and exercise, without allowing the animal to become excessively plethoric; moderate checking, allowing a free-and-easy movement of the head; well-ventilated stabling, proper cleanliness, pure water, etc.

SUNSTROKE, HEAT STROKE, OR HEAT EXHAUSTION.

The term sunstroke is applied to affections occasioned not exclusively by exposure to the sun's rays, as the word signifies, but by the action of great heat combined generally with humid atmosphere. Exhaustion produced by long-continued heat is often the essential factor, and is called heat exhaustion. Horses on the race track undergoing protracted and severe work in hot weather often succumb to heat exhaustion. Draft horses which do not receive proper care in watering, feeding, and rest in shady places and are exposed for many hours to the direct rays of the sun suffer very frequently from sunstroke.

Symptoms.--Sunstroke is manifested suddenly. The animal stops, drops his head, begins to stagger, and soon falls to the ground unconscious. The breathing is marked with great stertor, the pulse is very slow and irregular, cold sweats break out in patches on the surface of the body, and the animal often dies without having recovered consciousness.

The temperature becomes very high, reaching 105 deg. to 109 deg. F.

In heat exhaustion the animal usually requires urging for some time prior to the appearance of any other symptoms, generally perspiration is checked, and then the horse becomes weak in its gait, the breathing hurried or panting, eyes watery or bloodshot, nostrils dilated and highly reddened, assuming a dark, purple color; the pulse is rapid and weak, the heart bounding, followed by unconsciousness and death. If recovery takes place, convalescence extends over a long period of time, during which incoordination of movement may persist.

Pathology.--Sunstroke, virtually active congestion of the brain, often accompanied with effusion and blood extravasation, characterizes this condition, with often rapid and fatal lowering of all the vital functions. In many instances the death may be due to the complete stagnation in the circulation of the brain, inducing anemia, or want of nourishment of that organ. In other cases it may be directly due to the excessive compression of the nerve matter controlling the heart's action, and cause paralysis of that organ. There are also changes in the composition of the blood.

Treatment.--The animal should be placed in shaded surroundings. Under no circumstances is blood-letting permissible in sunstroke. Ice or very cold water should be applied to the head and along the spine, and half an ounce of carbonate of ammonia or 6 ounces of whisky should be given in 1 pint of water. Cold water may be used as an enema and should also be showered upon the body of the horse from the hose or otherwise. This should be continued until the temperature is down to 103 deg. F. Brisk friction of the limbs and the application of spirits of camphor often yields good results. The administration of the stimulants should be repeated in one hour if the pulse has not become stronger and slower. In either case, when reaction has occurred, preparations of iron and general tonics may be given during convalescence: Sulphate of iron, 1 dram; gentian, 3 drams; red cinchona bark, 2 drams; mix and give in feed morning and evening.

Prevention.--In very hot weather horses should have wet sponges or light sunshades on the head when at work, or the head may be sponged with cold water as many times a day as possible. Proper attention should be given to feeding and watering, never in excess. During the warm months all stables should be cool and well ventilated, and if an animal is debilitated from exhaustive work or disease it should receive such treatment as will tend to build up the system. Horses should be permitted to drink as much water as they want while they are at work during hot weather.

An animal which has been affected with sunstroke is very liable to have subsequent attacks when exposed to the necessary exciting causes.

APOPLEXY OR CEREBRAL HEMORRHAGE.

Apoplexy is often confounded with cerebral congestion, but true apoplexy always consists in rupture of cerebral blood vessels, with blood extravasation and formation of blood clot.

Causes.--Two causes are involved in the production of apoplexy, the predisposing and the exciting. The predisposing cause is degeneration, or disease which weakens the blood vessel; the exciting cause is any one which tends to induce cerebral congestion.

Symptoms.--Apoplexy is characterized by a sudden loss of sensation and motion, profound coma, and stertorous, difficult breathing. The action of the heart is little disturbed at first, but soon becomes slower, then quicker and feebler, and after a little time ceases. If the rupture is one of a small artery and the extravasation limited, sudden paralysis of some part of the body is the result. The extent and location of the paralysis depend upon the location within the brain which is functionally deranged by the pressure of the extravasated blood; hence these conditions are very variable.

In the absence of any premonitory symptoms or an increase of temperature in the early stage of the attack, we may be reasonably certain in making the distinction between this disease and congestion of the brain, or sunstroke.

Pathology.--In apoplexy there is generally found an atheromatous condition of the cerebral vessels, with weakening and degeneration of their walls. When a large artery has been ruptured it is usually followed by immediate death, and large rents may be found in the cerebrum, with great destruction of brain tissue, induced by the forcible pressure of the liberated blood. In small extravasations producing local paralysis without marked general disturbance the animal may recover after a time; in such cases gradual absorption of the clot takes place. In large clots atrophy of the brain substances may follow, or softening and abscess from want of nutrition may result, and render the animal worthless, ultimately resulting in death.

Treatment.--Place the animal in a quiet, cool place and avoid all stimulating feed. Administer, in the drinking water or feed, 2 drams of the iodid of potassium twice a day for several weeks if necessary. Medical interference with sedatives or stimulants is more liable to be harmful than of benefit, and blood-letting in an apoplectic fit is extremely hazardous. From the fact that cerebral apoplexy is due to diseased or weakened blood vessels, the animal remains subject to subsequent attacks. For this reason treatment is very unsatisfactory.

COMPRESSION OF THE BRAIN.

Causes.--In injuries from direct violence a piece of broken bone may press upon the brain, and, according to its size, the brain is robbed of its normal space within the cranium. It may also be due to an extravasation of blood or to exudation in the subdural or arachnoid spaces. Death from active cerebral congestion results through compression. The occurrence may sometimes be traced to the direct cause, which will give assurance for the correct diagnosis.

Symptoms.--Impairment of all the special senses and localized paralysis. All the symptoms of lessened functional activity of the brain are manifested to some degree. The paralysis remains to be our guide for the location of the cause, for it will be found that the paralysis occurs on the opposite side of the body from the location of the injury, and the parts suffering paralysis will denote, to an expert veterinarian or physician, the part of the brain which is suffering compression.

Treatment.--Trephining, by a skillful operator, for the removal of the cause when due to depressed bone or the presence of foreign bodies. When the symptoms of compression follow other acute diseases of the brain, apoplectic fits, etc., the treatment must be such as the exigencies of the case demands.

CONCUSSION OF THE BRAIN.

This is generally caused by falling over backward and striking the poll, or perhaps falling forward on the nose, by a blow on the head, etc. Train accidents during shipping often cause concussion of the brain.

Symptoms.--Concussion of the brain is characterized by giddiness, stupor, insensibility, or loss of muscular power, succeeding immediately upon a blow or severe injury involving the cranium. The animal may rally quickly or not for hours; death may occur on the spot or after a few days. When there is only slight concussion or stunning, the animal soon recovers from the shock. When more severe, insensibility may be complete and continue for a considerable time; the animal lies as if in a deep sleep; the pupils are insensible to light; the pulse fluttering or feeble; the surface of the body cold, muscles relaxed, and the breathing scarcely perceptible. After a variable interval partial recovery may take place, which is marked by paralysis of some parts of the body, often of a limb, the lips, ear, etc. Convalescence is usually tedious, and frequently permanent impairment of some organs remains.

Pathology.--Concussion produces laceration of the brain, or at least a jarring of the nervous elements, which, if not sufficiently severe to produce sudden death, may lead to softening or inflammation, with their respective symptoms of functional derangement.

Treatment.--The first object in treatment will be to establish reaction or to arouse the feeble and weakening heart. This can often be accomplished by dashing cold water on the head and body of the animal; frequent injections of weak ammonia water, ginger tea, or oil and turpentine should be given per rectum. In the majority of cases this will soon bring the horse to a state of consciousness. In more severe cases mustard poultices should be applied along the spine and above the fetlocks. As soon as the animal gains partial consciousness stimulants, in the form of whisky or capsicum tea, should be given. Owing to severity of the structural injury to the brain or the possible rupture of blood vessels and blood extravasation, the reaction may often be followed by encephalitis or cerebritis, and will then have to be treated accordingly. For this reason the stimulants should not be administered too freely, and they must be abandoned as soon as reaction is established. There is no need for further treatment unless complications develop as a secondary result. Bleeding, which is so often practiced, proves almost invariably fatal in this form of brain affection. We should also remember that it is never safe to drench a horse with large quantities of medicine when he is unconscious, for he is very liable to draw the medicine into the lungs in inspiration.

Prevention.--Young horses, when harnessed or bitted for the first few times, should not have their heads checked high, for it frequently causes them to rear up, and, being unable to control their balance, they are liable to fall over sideways or backwards, thus causing brain concussion when they strike the ground.

ANEMIA OF THE BRAIN.

This is a physiological condition in sleep. It is considered a disease or may give rise to disease when the circulation and blood supply of the brain are interfered with. In some diseases of the heart the brain becomes anemic, and fainting fits occur, with temporary loss of consciousness. Tumors growing within the cranium may press upon one or more arteries and stop the supply of blood to certain parts of the brain, thus inducing anemia, ultimately atrophy, softening, or suppuration. Probably the most frequent cause is found in plugging, or occlusion, of the arteries by a blood clot.

Symptoms.--Imperfect vision, constantly dilated pupils, frequently a feeble and staggering gait, and occasionally cramps, convulsions, or epileptic fits occur.

Pathology.--The exact opposite of cerebral hyperemia. The blood vessels are found empty, the membranes blanched, and the brain substance softened.

Treatment.--Removal of the remote cause when possible. General tonics, nutritious feed, rest, and removal from all causes of nervous excitement.

HYDROCEPHALUS, OR DROPSY OF THE BRAIN.

This condition consists in an unnatural collection of fluid about or in the brain. Depending upon the location of the fluid, we speak of external and internal hydrocephalus.

External hydrocephalus is seen chiefly in young animals. It consists in a collection of fluid under the meninges, but outside the brain proper. This defect is usually congenital. It is accompanied with an enlargement of the skull, especially in the region of the forehead. The pressure of the fluid may cause the bones to soften. The disease is incurable and usually fatal.

Internal hydrocephalus is a disease of mature horses, and consists in the accumulation of an excessive quantity of fluid in the cavities or ventricles of the cerebrum. The cause of this accumulation may be a previous inflammation, a defect in the circulation of blood through the brain, heat stroke, overwork, excessive nutrition, or long-continued indigestion. Common, heavy-headed draft horses are predisposed to this condition.

Symptoms.--The symptoms are an expression of dullness and stupidity, and from their nature this disease is sometimes known as "dumminess" or "immobility." A horse so afflicted is called a "dummy." Among the symptoms are loss of intelligence, stupid expression, poor memory, etc. The appetite is irregular; the horse may stop chewing with a wisp of hay protruding from his lips; he seems to forget that it is there. Unnatural positions are sometimes assumed, the legs being placed in clumsy and unusual attitudes. Such horses are difficult to drive, as they do not respond readily to the word, to pressure of the bit, or to the whip. Gradually the pulse becomes weaker, respiration becomes faster, and the subject loses weight. Occasionally there are periods of great excitement due to temporary congestion of the brain. At such times the horse becomes quite uncontrollable. A horse so afflicted is said to have "staggers." The outlook for recovery is not good.

Treatment is merely palliative. Regular work or exercise and nutritious feed easy of digestion, with plenty of fresh water, are strongly indicated. Intensive feeding should not be practiced. The bowels should be kept open by the use of appropriate diet or by the use of small regular doses of Glauber's salt.

TUMORS WITHIN THE CRANIUM.

Tumors within the cranial cavity and the brain occur not infrequently, and give rise to a variety of symptoms, imperfect control of voluntary movement, local paralysis, epilepsy, etc. Among the more common tumors are the following:

Osseous tumors, growing from the walls of the cranium, are not very uncommon.

Dentigerous cysts, containing a formation identical to that of a tooth, growing from the temporal bone, sometimes are found lying loose within the cranium.

Tumors of the choroid plexus, known as brain sand, are frequently met with on post-mortem examinations, but seldom give rise to any appreciable symptoms during life. They are found in horses at all ages, and are slow of development. They are found in one or both of the lateral ventricles, enveloped in the folds of the choroid plexus.

Melanotic tumors have been found in the brain and meninges in the form of small, black nodules in gray horses, and in one instance are believed to have induced the condition known as stringhalt.

Fibrous tumors may develop within or from the meningeal structures of the brain.

Gliomatous tumor is a variety of sarcoma very rarely found in the structure of the cerebellum.

Treatment for tumors of the brain is impossible.

SPASMS, OR CRAMPS.

Spasm is a marked symptom in many diseases of the brain and of the spinal cord. Spasms may result from irritation of the motor nerves as conductors, or may result from irritation of any part of the sympathetic nervous system, and they usually indicate an excessive action of the reflex motor centers. Spasms may be induced by various medicinal agents given in poisonous doses, or by effete materials in the circulation, such as nux vomica or its alkaloid strychnia, lead preparations, or an excess of the urea products in the circulation, etc. Spasms may be divided into two classes: Tonic spasm, when the cramp is continuous or results in persistent rigidity, as in tetanus; clonic spasm, when the cramping is of short duration, or is alternated with relaxations. Spasms may affect involuntary as well as the voluntary muscles, the muscles of the glottis, intestines, and even the heart. They are always sudden in their development.

Spasm of the glottis.--This is manifested by a strangling respiration; a wheezing noise is produced in the act of inspiration; extreme anxiety and suffering for want of air. The head is extended, the body profusely perspiring; pulse very rapid; soon great exhaustion becomes manifest; the mucous membranes become turgid and very dark colored, and the animal thus may suffocate in a short time.

Spasm of the intestines.--(See "Cramp colic," p. 74.)

Spasm of the neck of the bladder.--This may be due to spinal irritation or a reflex from intestinal irritation, and is manifested by frequent but ineffectual attempts to urinate.

Spasm of the diaphragm, or thumps.--Spasmodic contraction of the diaphragm, the principal muscle used in respiration, is generally occasioned by extreme and prolonged speeding on the race track or road. The severe strain thus put upon this muscle finally induces irritation of the nerves controlling it, and the contractions become very forcible and violent, giving the jerking character known among horsemen as "thumps." This condition may be distinguished from violent beating of the heart by feeling the pulse beat at the angle of the jaw, and at the same time watching the jerking movement of the body, when it will be discovered that the two bear no relation to each other. (See "Palpitation of the heart," p. 259.)

Spasm of the thigh, or cramp of a hind limb.--This is frequently witnessed in horses that stand on sloping plank floors--generally in cold weather--or it may come on soon after severe exercise. It is probably due to an irritation of the nerves of the thigh. In cramps of the hind leg the limb becomes perfectly rigid, and attempts to flex are unsuccessful; the animal stands on the affected limb, but is unable to move it; it is unnaturally cold; it does not, however, appear to cause much suffering unless attempts are made to change position. This cramp may be of short duration--a few minutes--or it may persist for several days. This condition is often taken for a dislocation of the stifle joint. In the latter the foot is extended backward, and the horse is unable to advance it, but drags the limb. An examination of the joint also reveals a change in form. Spasms may affect the eyelids, by closure or by retraction. Spasm of the sterno-maxillaris muscle has been witnessed, and the animal was unable to close the jaws until the muscle became relaxed.

Treatment of spasms.--An anodyne liniment, composed of chloroform 1 part and soap liniment 4 parts, applied to cramped muscles will usually cause relaxation. This may be used when single external muscles are affected. In spasms of the glottis, inhalation of sulphuric ether will give quick relief. In spasm of the diaphragm, rest and the administration of half an ounce of chloroform in 3 ounces of whisky, with a pint of water added, will generally suffice to bring relief, or if this fails give 5 grains of sulphate of morphia by hypodermic injection. If spasms result from organic disease of the nervous system, the latter should receive such treatment as its character demands. In cramp of the leg, compulsory movement usually causes relaxation very quickly; therefore the animal should be led out of the stable and be forced to run or trot. Sudden, nervous excitement caused by a crack of the whip or smart blow will often bring about immediate relief. Should this fail, the anodyne liniment may be used along the inside of the thigh, and chloroform, ether, or laudanum given internally. An ounce of the chloral hydrate will certainly relieve the spasm when given internally, but the cramp may return soon after the effect has passed off, which in many cases it does very quickly.

Convulsions.--Although there is no disease of the nervous system which can be properly termed convulsive, or justify the use of the word convulsion to indicate any particular disease, yet it is often such a prominent symptom that a few words may not be out of place. General, irregular muscular contractions of various parts of the body, with unconsciousness, characterize what we regard as convulsions, and like ordinary spasms are dependent upon some disease or irritation of the nervous structures, chiefly of the brain. No treatment is required; in fact, a general convulsion must necessarily be self-limited in its duration. Suspending, as it does, respiratory movements, checking the oxygenation and decarbonization of the blood, the rapid accumulation of carbonic-acid gas in the blood and the exclusion of oxygen quickly puts the blood in a condition to produce the most reliable and speedy sedative effect upon the nerve excitability that could be found, and consequently furnishes its own remedy so far as the continuance of the convulsive paroxysm is concerned. Whatever treatment is instituted must be directed toward a removal of the cause of the convulsive paroxysm.

CHOREA, OR ST. VITUS'S DANCE.

Chorea is characterized by involuntary contractions of voluntary muscles. This disease is an obscure disorder, which may be from pressure upon a nerve, cerebral or spinal sclerosis, small aneurisms in the brain, etc. Choreic symptoms have been produced by injecting granules of starch into the arteries entering the brain. Epilepsy and other forms of convulsions simulate chorea in appearance.

Stringhalt is by some termed "chorea." This is manifested by a sudden jerking up of one or both hind legs when the animal is walking. This symptom may be very slight in some horses, but has a tendency to increase with age. In some the catching up of the affected leg is very violent, and when it is lowered to the ground the motion is equally sudden and forcible, striking the foot to the ground like a pile driver. Very rarely chorea may be found to affect one of the fore legs, or the muscles of one side of the neck or the upper part of the neck. Involuntary jerking of the muscles of the hip or thigh is seen occasionally, and is termed "shivering" by horsemen.

Chorea is often associated with a nervous disposition, and is not so frequent in animals with a sluggish temperament. The involuntary muscular contractions cause no pain, and do not appear to produce much exhaustion of the affected muscles, although the jerking may be regular and persistent whenever the animal is in motion.

Treatment.--In a few cases, early in the appearance of this affection, general nerve tonics may be of benefit, viz, iodid of iron, 1 dram; pulverized nux vomica, 1 dram; pulverized scutellaria (skull-cap), 1 ounce. Mix and give in the feed once a day for two weeks. Arsenic in the form of Fowler's solution is often beneficial. If the cause is connected with organic brain lesions, treatment is usually unsuccessful.

EPILEPSY, OR FALLING FITS.

The cause of epilepsy is seldom traceable to any special brain lesions. In a few cases it accompanies disease of the pituitary body, which is located in the under surface of the brain. Softening of the brain may give rise to this affection. Attacks may occur only once or twice a year or they may be of frequent recurrence.

Symptoms.--No premonitory symptoms precede an epileptic fit. The animal suddenly staggers; the muscles become cramped; the jaws may be spasmodically opened and closed, and the tongue become lacerated between the teeth; the animal foams at the mouth and falls in a spasm. The urine flows involuntarily, and the breathing may be temporarily arrested. The paroxysm soon passes off, and the animal gets on its feet in a few minutes after the return of consciousness.

Treatment.--Dashing cold water on the head during the paroxysm. After the recovery 1 dram of oxid of zinc may be given in the feed twice a day for several weeks, or benefit may be derived from the tonic prescribed for chorea.

PARALYSIS, OR PALSY.

Paralysis is a weakness or cessation of the muscular contraction by diminution of loss of the conducting power or stimulation of the motor nerves. Paralytic affections are of two kinds, the complete and the incomplete. The former includes those in which both motion and sensibility are affected; the latter those in which only one or the other is lost or diminished. Paralysis may be general or partial. The latter is divided into hemiplegia and paraplegia. When only a small portion of the body is affected, as the face, a limb, the tail, it is designated by the term local paralysis. When the irritation extends from the periphery of the center it is termed reflex paralysis.

Causes are much varied. Most of the acute affections of the brain and spinal cord may lead to paralysis. Injuries, tumors, disease of the blood vessels of the brain, etc., all have a tendency to produce suspension of the conducting motive power to the muscular structures. Pressure upon, or the severing of, a nerve causes a paralysis of the parts to which such a nerve is distributed. Apoplexy may be termed a general paralysis, and in nonfatal attacks is a frequent cause of the various forms of palsy.

GENERAL PARALYSIS.--This can not take place without producing immediate death. The term is, however, usually applied to paralysis of the four extremities, whether any other portions of the body are involved or not. This form of palsy is due to compression of the brain by congestion of its vessels, large clot formation in apoplexy, concussion, or shock, or any disease in which the whole brain structure is involved in functional disturbance.

HEMIPLEGIA (PARALYSIS OF ONE SIDE OR HALF OF THE BODY).--Hemiplegia is frequently the result of a tumor in the lateral ventricles of the brain, softening of one hemisphere of the cerebrum, pressure from extravasated blood, fracture of the cranium, or it may be due to poisons in the blood or to reflex origin. When hemiplegia is due to or the result of a prior disease of the brain, especially of an inflammatory character, it is seldom complete; it may affect only one limb and one side of the head, neck, or muscles along the back, and may pass off in a few days after the disappearance of all the other evidences of the primary affection. In most cases, however, hemiplegia arises from emboli obstructing one or more blood vessels of the brain, or the rupture of some vessel the wall of which had become weakened by degeneration and the extravasation of blood. Sensibility in most cases is not impaired, but in some there is a loss of sensibility as well as of motion. In some cases the bladder and rectum are involved in the paralysis.

Symptoms.--In hemiplegia the attack may be very sudden, and the animal fall, powerless to move one side of the body; one side of the lips will be relaxed; the tongue may hang out on one side of the mouth; the tail curved around sideways; an inability to swallow feed or water may be present, and often the urine dribbles away as fast as it collects in the bladder. Sensibility of the affected side may be entirely lost or only partial; the limbs may be cold and sometimes unnaturally warm. In cases wherein the attack is not so severe the animal may be able to maintain the standing position, but will have great difficulty in moving the affected side. In such cases the animal may recover from the disability. In the more severe, in which there is complete loss of power of movement, recoveries are rare.

PARAPLEGIA (TRANSVERSE PARALYSIS OF THE HIND EXTREMITIES).--Paralysis of the hind extremities is usually due to some injury or inflammation affecting the spinal cord. (See "Spinal meningitis," p. 232, and "Myelitis," p. 233.) It may also be due to a reflex irritation from disease of peripheral nerves, to spinal irritation or congestion caused by blood poisons, etc.

Symptoms.--When due to mechanical injury of the spinal cord, from a broken back or spinal hemorrhage, it is generally progressive in its character, although it may be sudden. When it is caused by agents in the blood, it may be intermittent or recurrent.

Paraplegia is not difficult to recognize, for it is characterized by a weakness and imperfect control of the hind legs and powerless tail. The urine usually dribbles away as it is formed and the manure is pushed out, ball by ball, without any voluntary effort, or the passages may cease entirety. When paraplegia is complete, large and ill-conditioned sores soon form on the hips and thighs from chafing and bruising, which have a tendency quickly to weaken the animal and necessitate his destruction.

LOCOMOTOR ATAXIA, OR INCOORDINATION OF MOVEMENT.--This is characterized by an inability to control properly the movement of the limbs. The animal appears usually perfectly healthy, but when he is led out of his stall his legs have a wobbly movement and he will stumble or stagger, especially in turning. When this is confined to the hind parts it may be termed a modified form of paraplegia, but often it may be seen to affect nearly all the voluntary muscles when they are called into play, and must be attributed to some pressure exerted on the base of the brain.

LOCAL PARALYSIS.--This is frequently met with in horses. It may affect many parts of the body, even vital organs, and it is very frequently overlooked in diagnosis.

FACIAL PARALYSIS.--This is a frequent type of local paralysis, and is due to impairment of function of the motor nerve of the facial muscles, the portio dura. The cause may exist at the base of the brain, compression along its course after it leaves the medulla oblongata, or to a bruise after it spreads out on the great masseter muscle.

Symptoms.--A flaccid condition of the cheek muscles, pendulous lips, inability to grasp the feed, often a slow and weak movement in chewing, and difficulty and slowness in drinking.

LARYNGISMUS PARALYTICUS, OR ROARING.--This condition is characterized by roaring, and is usually caused by an inflamed or hypertrophied bronchial gland pressing against the left recurrent laryngeal nerve, which interferes with its conducting power. A similar condition is occasionally induced in acute pleurisy, when the recurrent nerve becomes involved in the diseased process or compressed by plastic exudation.

PARALYSIS OF THE RECTUM AND TAIL.--This is generally the result of a blow or fall on the rump, which causes a fracture of the sacrum bone and injury to the nerves supplying the tail and part of the rectum and muscles belonging thereto. This fracture would not be suspected were it not for the loss of motion of the tail.

INTESTINAL PARALYSIS.--Characterized by persistent constipation; frequently the strongest purgatives have no effect whatever on the movement of the bowels. In the absence of symptoms of indigestion, or special diseases implicating the intestinal canal, torpor of the bowels must be attributed to deficient innervation. This condition may depend upon brain affections or be due to reflex paralysis. Sudden checks of perspiration may induce excessive action of the bowels or paralysis.

PARALYSIS OF THE BLADDER.--This usually affects the neck of the bladder, and is characterized by incontinence of urine; the urine dribbles away as fast as it is secreted. The cause may be of reflex origin, disease of the rectum, tumors growing within the pelvic cavity, injury to the spinal cord, etc.

PARALYSIS OF THE OPTIC NERVE (AMAUROSIS).--A paralysis of eyesight may occur very suddenly from rupture of a blood vessel in the brain, acute local congestion of the brain, the administration of excessive doses of belladonna or its alkaloid atropia, etc. In amaurosis the pupil is dilated to its full extent; the eye looks clear, but does not respond to light.

Paralysis of hearing, of the external ear, of the eyelid, partial paralysis of the heart and organs of respiration, of the blood vessels from injury to the vasomotor nerves of the esophagus, or loss of deglutition, palsy of the stomach, all may be manifested when the supply of nervous influence is impaired or suspended.

TREATMENT FOR PARALYSIS.--In all paralytic affections there may be anesthesia, or impairment of sensibility, in addition to the loss of motion, or there may be hyperesthesia, or increased sensibility, in connection with the loss of motion. These conditions may call for special treatment in addition to that for loss of motion. If hyperesthesia is well marked local anodynes may be needed to relieve suffering. Chloroform liniment or hypodermic injections of from 3 to 5 grains of sulphate of morphia will allay local pain. If there is marked anesthesia, or loss of sensibility, it may become necessary to secure the animal in such way that he can not suffer serious injury from accidents which he can not avoid or feel. In the treatment of any form of paralysis we must always refer to the cause, and attempt its removal if it can be discovered. In cases in which the cause can not be determined we have to rely solely upon a general external and internal treatment. Externally, fly blisters or strong, irritant liniments may be applied to the paralyzed parts. In hemiplegia they should be applied along the bony part of the side of the neck; in paraplegia, across the loins. In, some cases hot-water cloths will be beneficial. Internally, it is well to administer 1 dram of powdered nux vomica or 2 grains of sulphate of strychnia twice a day until twitching of some of the voluntary muscles occurs; then discontinue it for several days, and then commence again with a smaller dose, gradually increasing it until twitching recurs. Iodid of potassium in 1 to 2 dram doses two or three times daily may be used with the hope that it will favor the absorption of the clot or obstruction to the nervous current. In some cases Fowler's solution of arsenic in teaspoonful doses twice a day in the drinking water proves beneficial. Occasionally benefit may be derived from the application of the electric current, especially in cases of roaring, facial paralysis, paralysis of the eyelid, etc. Nutritious but not too bulky feed, good ventilation, clean stabling, moderate exercise if the animal is capable of taking it, good grooming, etc., should be observed in all cases.

SPINAL MENINGITIS, OR INFLAMMATION OF THE MEMBRANES ENVELOPING THE SPINAL CORD.

This may be induced by the irritant properties of blood poisons, exhaustion and exposure, spinal concussion, all forms of injury to the spine, tumors, caries of the vertebrae, rheumatism, etc.

Symptoms.--A chill may be the precursor, a rise in temperature, or a general weakness and shifting of the legs. Soon a painful, convulsive twitching of the muscles sets in, followed by muscular rigidity along the spine, in which condition the animal will move very stiffly and evince great pain in turning. Evidences of paralysis or paraplegia develop, retention or incontinence of urine, and oftentimes sexual excitement is present. The presence of marked fever at the beginning of the attack, associated with spinal symptoms, should lead us to suspect spinal meningitis or myelitis. These two conditions usually appear together, or myelitis follows inflammation of the meninges so closely that it is almost impossible to separate the two; practically it does not matter much, for the treatment will be about the same in both cases. Spinal meningitis generally becomes chronic, and is then marked principally by paralysis of that portion, or parts of it, posterior to the seat of the disease.

Pathology.--In spinal meningitis we find essentially the same condition as in cerebral meningitis; there is an effusion of serum between the membranes, and often a plastic exudation firmly adherent to the pia mater serves to maintain a state of paralysis for a long time after the acute symptoms have disappeared by compressing the cord. Finally, atrophy, softening, and even abscess may develop within the cord. Unlike in man, it is usually found localized in horses.

Treatment.--Bags filled with ice should be applied along the spine, to be followed later by strong blisters. The fever should be controlled as early as possible by giving 20 drops of Norwood's tincture of veratrum viride every hour until the desired result is obtained. One dram of the fluid extract of belladonna, to control pain and vascular excitement of the spinal cord, may be given every five or six hours until the pupils of the eyes become pretty well dilated. If the pain is very intense 5 grains of sulphate of morphia should be injected hypodermically. The animal must be kept as free from excitement as possible. If the urine is retained in the bladder it must be drawn off every four or six hours. In very acute attacks the disease generally proves fatal in a few days. If, however, the animal grows better, some form of paralysis is liable to remain for a long time, and the treatment will have to be directed then toward a removal of the exudative products and a strengthening of the system and stimulation of the nervous functions. To induce absorption, iodid of potassium in 2-dram doses, dissolved in the drinking water, may be given twice a day. To strengthen the system, iodid of iron 1 dram twice a day and 1 dram of nux vomica once a day may be given in the feed. Electricity to the paralyzed and weakened muscles is advisable; the current should be weak, but be continued for half an hour two or three times daily. If the disease is due to a broken back, caries of the vertebrae, or some other irremediable cause, the animal should be destroyed at once.

MYELITIS, OR INFLAMMATION OF THE SUBSTANCE OF THE SPINAL CORD.

This is a rare disease, except as a secondary result of spinal meningitis or injuries to the spine. Poisoning by lead, arsenic, mercury, phosphorus, carbonic-acid gas, etc., has been known to produce it. Myelitis may be confined to a small spot in the cord or may involve the whole for a variable distance. It may lead to softening abscess or degeneration.

Symptoms.--The attack may begin with a chill or convulsion; the muscles twitch or become cramped very early in the disease, and the bladder usually is affected at the outset, in which there may be either retention or incontinence of urine. These conditions are followed by complete or partial paralysis of the muscles posterior to the locality of the inflamed cord, and the muscles begin to waste away rapidly. The paralyzed limb becomes cold and dry, due to the suspension of proper circulation; the joints may swell and become edematous; vesicular eruptions appear on the skin; and frequently gangrenous sloughs form on the paralyzed parts. It is exceedingly seldom that recovery takes place. In a few instances it may assume a chronic type, when all the symptoms become mitigated, and thus continue for some time, until septicemia, pyemia, or exhaustion causes death.

Pathology.--The inflammation may involve nearly the whole length of the cord, but generally it is more intense in some places than others; when due to mechanical injury, the inflammation may remain confined to a small section. The cord is swollen and congested, reddened, often softened and infiltrated with pus cells, and the nerve elements are degenerated.

Treatment.--Similar to that of spinal meningitis.

SPINAL CONGESTION.

This condition consists in an excess of blood. As the blood vessels of the pia mater are the principal source of supply to the spinal cord, hyperemia of the cord and of the meninges usually go together. The symptoms are, therefore, closely allied to those of spinal meningitis and congestion. When the pia mater is diseased, the spinal cord is almost invariably affected also.

Cause.--Sudden checking of the perspiration, violent exercise, blows, and falls.

Symptoms.--The symptoms may vary somewhat with each case, and closely resemble the first symptoms of spinal meningitis, spinal tumors, and myelitis. First, some disturbance in movement, lowering the temperature, and partial loss of sensibility posterior to the seat of the congestion. If in the cervical region, it may cause interference in breathing and the action of the heart. When in the region of the loins, there may be loss of control of the bladder. When the congestion is sufficient to produce compression of the cord, paraplegia may be complete. Usually fever, spasms, muscular twitching, or muscular rigidity are absent, which will serve to distinguish spinal congestion from spinal meningitis.

Treatment.--Hot-water applications to the spine, 1-dram doses fluid extract of belladonna repeated every four hours, and tincture of aconite root 20 drops every hour until the symptoms become ameliorated. If no inflammatory products occur, the animal is likely to recover.

SPINAL ANEMIA.

This may be caused by extreme cold, exhausting diseases, spinal embolism or plugging of a spinal blood vessel, an interference with the circulation through the abdominal aorta, from compression, thrombosis, or aneurism of that vessel; the spinal vessels may be caused to contract through vasomotor influence, a result of peripheral irritation of some nerve.

Spinal anemia causes paralysis of the muscles used in extending the limbs. When the bladder is affected, it precedes the weakness of motion, while in spinal congestion it follows, and increased sensibility, in place of diminished sensibility, as in spinal congestion, is observed. Pressure along the spine causes excessive pain.

If the exciting cause can be removed, the animal recovers; if this fails, the spinal cord may undergo softening.

SPINAL COMPRESSION.

When caused by tumors or otherwise, when pressure is slight, it produces a paralysis of the muscles used in extending a limb and contraction of those which flex it. When compression is great it causes complete loss of sensibility and motion posterior to the compressed part of the cord.

Compression of a lateral half of the cord produces motor paralysis, disturbance of the circulation, and difficulty of movement, an increased sensibility on the side corresponding to the compressed section, and a diminished sensibility and some paralysis on the opposite side.

Treatment.--When it occurs as a sequence of a preceding inflammatory disease, iodid of potassium and general tonics are indicated. When due to tumors growing within the spinal canal, or to pressure from displaced bone, no form of treatment will result in any benefit.

SPINAL HEMORRHAGE.

This may occur from changes in the wall of the blood vessels, in connection with tumors, acute myelitis, traumatic injuries, etc. The blood may escape through the pia mater into the subarachnoid cavity, and large clots be formed.

Symptoms.--The symptoms are largely dependent upon the seat and extent of the hemorrhage, as they are principally owing to the compression of the cord. A large clot may produce sudden paraplegia, accompanied with severe pain along the spine; usually, however, the paralysis of both motion and sensation is not very marked at first; on the second or third day fever is liable to appear, and increased or diminished sensibility along the spine posterior to the seat of the clot. When the bladder and rectum are involved in the symptoms it indicates that the spinal cord is compressed.

Treatment.--In the occurrence of injuries to the back of a horse, whenever there is any evidence of paralysis, it is always advisable to apply bags of ice along the spine to check or prevent hemorrhage or congestion, and 2 drams of the fluid extract of ergot and 20 drops of tincture of digitalis may be given every hour until three doses have been taken. Subsequently tincture of belladonna in half-ounce doses may be given three times a day. If there is much pain, 5 grains of sulphate of morphia, injected under the skin, will afford relief and lessen the excitability of the animal. In all cases the animal should be kept perfectly quiet.

SPINAL CONCUSSION.

This is rarely observed in the horse, and unless it is sufficiently severe to produce well-marked symptoms it would not be suspected. It may occur in saddle horses from jumping, or it may be produced by falling over an embankment, or a violent fall upon the haunches may produce it. Concussion may be followed by partial paralysis or spinal hemorrhage; generally, however, it is confined to a jarring and some disturbance of the nerve elements of the cord, and the paralytic effect which ensues soon passes off. Treatment consists in rest until the animal has completely recovered from the shock. If secondary effects follow from hemorrhage or compression, they have to be treated as heretofore directed.

SPINAL TUMORS.

Within the substance of the cord glioma or the mixed gliosarcomata are found to be the most frequent, tumors may form from the meninges and the vertebrae, being of a fibrous or bony nature, and affect the spinal cord indirectly by compression. In the meninges we may find glioma, cancers, and psammoma, fibromata; aneurisms of the spinal arteries have been discovered in the spinal canal.

Symptoms.--Tumors of the spinal canal cause symptoms of spinal irritation or compression of the cord. The gradual and slow development of symptoms of paralysis of one or both hind limbs or certain muscles may lead to a suspicion of spinal tumors. The paralysis induced is progressive, but not usually marked with atrophy of the muscles or increased sensibility along the spine. When the tumor is within the spinal cord itself all the symptoms of myelitis may be present.

Treatment.--General tonics and 1-dram doses of nux vomica may be given; iodid of iron or iodid of potassium in 1-dram doses, three times a day in feed, may, in a very few cases, give some temporary benefit. Usually the disease progresses steadily until it proves fatal.

NEURITIS, OR INFLAMMATION OF A NERVE.

This is caused by a bruise or wound of a nerve or by strangulation in a ligature when the nerve is included in the ligation of an artery. The changes in an inflamed nerve are an enlargement, reddening of the nerve sheath, spots of extravasated blood, and sometimes an infiltration of serum mixed with pus.

Symptoms.--Acute pain of the parts supplied by the nerve and absence of swelling or increased heat of the part.

Treatment.--Hypodermic injections of from 3 to 5 grains of morphia to relieve pain, hot fomentations, and rest. If it is due to an inclusion of a ligature, the nerve should be divided above and below the ligature.

NEUROMA, OR TUMOR OF A NERVE.

Neuroma may be from enlargement of the end of a divided nerve or due to fibrous degeneration of a nerve which has been bruised or wounded. Its most frequent occurrence is found after the operation of neurotomy for foot lameness, and it may appear after the lapse of months or even years. Neuroma usually develops within the sheath of the nerve with or without implicating the nerve fibers. It is oval, running lengthwise with the direction of the nerve.

Symptoms.--Pain of the affected limb or part is manifested, more especially after resting a while, and when pressure is made upon the tumor it causes extreme suffering.

Treatment.--Excision of the tumor, including part of the nerve above and below, and then treat it like any other simple wound.

INJURIES TO NERVES.

These may consist in wounding, bruising, laceration, stretching, compression, etc. The symptoms which are produced will depend upon the extent, seat, and character of the injury. Recovery may quickly take place, or it may lead to neuritis, neuroma, or spinal or cerebral irritation, which may result in tetanus, paralysis, and other serious derangements. In all diseases, whether produced by some form of external violence or intrinsic causes, the nerves are necessarily involved, and sometimes it is to a primary injury of them that the principal fault in movement or change of nutrition of a part is due. It is often difficult or impossible to discover that an injury to a nerve has been inflicted, but whenever this is possible it may enable us to remedy that which otherwise would result in permanent evil. Treatment should consist in relieving compression, in hot fomentations, the application of anodyne liniments, excision of the injured part, and rest.

FORAGE POISONING, OR SO-CALLED CEREBROSPINAL MENINGITIS.

This disease prevails among horses in nearly all parts of the United States. Its appearance in America is by no means of recent occurrence, for the malady was reported by Large in 1847, by Michener in 1850, and by Liautard in 1869 as appearing in both sporadic and enzootic form in several of the Eastern States. Since then the disease has occurred periodically in many States in all sections of the country, and has been the subject of numerous investigations and publications by a number of the leading men of the veterinary profession. It is prevalent with more or less severity every year in certain parts of the United States, and during the year 1912 the Bureau of Animal Industry received urgent requests for help from Colorado, Georgia, Iowa, Kansas, Kentucky, Louisiana, Maryland, Missouri, Nebraska, New Jersey, North Carolina, Oregon, South Carolina, South Dakota, Virginia, and West Virginia. While in 1912 the brunt of the disease seemed to fall on Kansas and Nebraska, other States were also seriously afflicted. In previous years, for instance in 1882, as well as in 1897, the horses of southeastern Texas were reported to have died by the thousand, and in the following year the horses of Iowa were said to have "died like rats." However, Kansas seems to have had more than her share of this trouble, as a severe outbreak that extended over almost the entire State occurred in 1891, while in 1902 and again in 1906 the disease recurred with equal severity in various portions of the State.

This condition consists in a poisoning and depression of the nervous system from eating or drinking feed or water containing poison generated by mold or bacteria. It has been shown to be owing to eating damaged ensilage, corn, brewers' grains, oats, etc., or to drinking stagnant pond water or water from a well contaminated by surface drainage. Horses at pasture may contract the disease when the growth of grass is so profuse that it mats together and the lower part dies and ferments or becomes moldy.

In England a similar disease has been called "grass staggers," due to eating rye grass when it is ripening or when it is cut and eaten while it is heating and undergoing fermentation. In eastern Pennsylvania it was formerly known by the name of "putrid sore throat" and "choking distemper." A disease similar in many respects which is very prevalent in Virgina, especially along the eastern border, is commonly known by the name of "blind staggers," and in many of the Southern States this has been attributed to the consumption of worm-eaten, corn. Horses of all ages and mules are subject to this disease.

Symptoms and lesions.--The symptoms which typify sporadic or epidemic cerebrospinal meningitis in man are not witnessed among horses, namely, excessive pain, high fever, and early muscular rigidity. In the recognition of the severity of the attack we may divide the symptoms into three grades. In the most rapidly fatal attacks the animal may first indicate it by weak, staggering gait, partial or total inability to swallow solids or liquids, impairment of eyesight; twitching of the muscles and slight cramps may be observed. As a rule, the temperature is not elevated--indeed, it is sometimes below normal. This is soon followed by a paralysis of the whole body, inability to stand, delirium in which the animal sometimes goes through a series of automatic movements as if trotting or running; the delirium may become very violent and the unconscious animal may bruise his head very seriously in his struggles; but usually a deep coma renders him quiet until he expires. Death in these cases usually takes place in from 4 to 24 hours from the time the first symptoms become manifest. The pulse is variable during the progress of the disease; it may be almost imperceptible at times, and then again very rapid and irregular; the respirations generally are quick and catching. In the next form in which this disease may develop it first becomes manifest by a difficulty in swallowing and slowness in mastication, and a weakness which may be first noticed in the strength of the tail; the animal will be unable to switch it or to offer resistance when we bend it up over the croup. The pulse is often a little slower than normal. There is no evidence of pain; the respirations are unchanged, and the temperature little less than normal; the bowels may be somewhat constipated. These symptoms may remain unchanged for two or three days and then gradual improvement may take place, or the power to swallow may become entirely lost and the weakness and uncertainty in gait more and more perceptible; then sleepiness or coma may appear; the pulse becomes depressed, slow, and weak, the breathing stertorous, and paroxysms of delirium develop, with inability to stand, and some rigidity of the spinal muscles or partial cramp of the neck and jaws. In such cases death may occur in from 6 to 10 days from the commencement of the attack. In many cases there is no evidence of pain, spasm, or fever at any time during the progress of the disease, and finally profound coma develops and death follows, painless and without a struggle.

In the last or mildest form the inability of voluntary control of the limbs becomes but slightly marked, the power of swallowing never entirely lost, and the animal has no fever, pain, or unconscious movements. Generally the animal will begin to improve about the fourth day and recovers.

In a few cases the spinal symptoms, manifested by paraplegia, may be the most prominent symptoms; in others they may be altogether absent and the main symptoms may be difficulty in mastication and swallowing; rarely it may affect one limb only. In all cases in which coma remains absent for six or seven days the animal is likely to recover. When changes toward recovery take place, the symptoms usually leave in the reverse order to that in which they developed, but local paralysis may remain for some time, rarely persistent.

On post-mortem the number of lesions observable to the naked eye is in marked contrast to the severity of the symptoms noted. The pharynx and larynx are inflamed in many cases, and sometimes coated with a yellowish-white glutinous deposit, extending at times over the tongue and occasionally a little way down the trachea. The lungs are normal, except from complications following drenching or recumbence for a long period. The heart is usually normal in appearance, except an occasional cluster of hemorrhagic points on the outer surface, while the blood is dark and firmly coagulated. The lining of the stomach indicates a subacute gastritis, while occasionally an erosion is noted. An edema is observed in the submucosa of such cases. The first few inches of the small intestines likewise may show slight inflammation in certain cases, while in others it is quite severe; otherwise the digestive tract appears normal, excluding the presence of varying numbers of bots, Strongylus vulgatus, and a few other nematodes. The liver is congested and swollen in some cases, while it appears normal in others. The spleen is, as a rule, normal, and at times the kidneys are slightly congested. The bladder is often distended with dark-colored urine, and occasionally a marked cystitis has been observed. The adipose tissue throughout the carcass may show a pronounced icteric appearance in certain cases. On removing the bones of the skull the brain appears to be normal macroscopically in a few instances, but in most cases the veins and capillaries of the meninges of the cerebrum, cerebellum, and occasionally the medulla is distinctly dilated and engorged, and in a few cases there are pronounced lesions of a leptomeningitis. An excessive quantity of cerebrospinal fluid is present in most of the cases. On the floor of the lateral ventricles of several brains there was noted a slight softening caused by hemorrhages into the brain substance. There is always an abundance of fluid in the subarachnoid spaces, ventricles, and at the base of the brain, usually of the color of diabetic urine, and containing a limited number of flocculi, but in a few cases it was slightly blood tinged. The spinal cord was not found involved in the few cases examined.

Treatment.--One attack of the disease does not confer immunity. Horses have been observed which have recovered from two attacks, and still others that recovered from the first but died as a result of the second attack.

Inasmuch as a natural immunity does not appear after an attack of cerebrospinal meningitis, it might be anticipated that serum of recovered cases would possess neither curative nor prophylactic qualities. Nevertheless, experiments have been made along these lines with serum from recovered cases, but without any positive results. Similar investigations have been conducted by others in Europe with precisely the same results. With the tendency of the disease to produce pathological lesions in the central nervous system, it seems scarcely imaginable that a medicinal remedy will be found to heal these foci, and even when recovery takes place considerable disturbance in the functions, as blindness, partial paralysis, dumbness, etc., is liable to remain. Indeed, when the disease once becomes established in an animal, drugs seem to lose their physiological action. Therefore, with all the previously mentioned facts before us, it is evident that the first principle in the treatment of this disease is prevention, which consists in the exercise of proper care in feeding only clean, well-cured forage and grain and pure water. These measures when faithfully carried out check the development of additional cases of the disease upon the affected premises.

While medicinal treatment has proved unsatisfactory in most cases, nevertheless the first indication is to clean out the digestive tract thoroughly, and to accomplish this prompt measures must be used early in the disease. Active and concentrated remedies should be given, preferably subcutaneously or intravenously, owing to the great difficulty in swallowing, even in the early stage. Arecolin in one-half grain doses, subcutaneously, has given as much satisfaction as any other drug. After purging the animal the treatment is mostly symptomatic. Intestinal disinfectants, particularly calomel, salol, and salicylic acid, have been recommended, and mild, antiseptic mouth washes are advisable. Antipyretics are of doubtful value, as better results are obtained, if the temperature is high, by copious cold-water injections. An ice pack applied to the head is beneficial in case of marked psychic disturbance. One-ounce doses of chloral hydrate per rectum should be given if the patient is violent or if muscular spasms are severe. If the temperature becomes subnormal, the animal should be warmly blanketed, and if much weakness is shown this should be combated with stimulants, such as strychnin, camphor, alcohol, atropin, or aromatic spirits of ammonia. Early in the disease urotropin (hexamethylenamin) in doses of 25 grains, dissolved in water and given by the mouth every two hours, appeared to have been responsible for the recovery of some cases of the malady. During convalescence tonic treatment is indicated.

Hygienic measures needful.--Whenever this disease appears in a stable all the animals should be removed as soon as possible. They should be provided with clean, well-ventilated, and well-drained stables, and each animal should receive a laxative and be fed feed and given water from a new, clean source. The abandoned stable should be thoroughly cleansed from all waste matters, receive a coat of whitewash containing 4 ounces of carbolic acid to the gallon of water and should have time to dry thoroughly before the horses are replaced. A complete change of feed is of the very greatest importance on account of the belief that the cause resides in diseased grain, hay, and grass.

TETANUS, OR LOCKJAW.

This disease is characterized by spasms affecting the muscles of the face, neck, body, and limbs and of all muscles supplied by the cerebrospinal nerves. The spasms or muscular contractions are rigid and persistent, yet mixed with occasional more intense contractions of convulsive violence.

Causes.--This disease is caused by a bacillus that is often found in the soil, in manure, and in dust. This germ forms spores at the end of the organism and grows only in the absence of oxygen. It produces a powerful nerve poison, which causes the symptoms of tetanus. The germ itself multiplies at the point where it is introduced, but its poison is absorbed and is carried by the blood to all parts of the body, and thus the nervous system is poisoned. Deep wounds infected by this germ are more dangerous than superficial wounds, because in them the germ is more remote from the oxygen of the air. Hence, nail pricks, etc., are especially dangerous. In the majority of instances the cause of tetanus can be traced to wounds, especially pricks and wounds of the feet or of tendinous structures. It sometimes follows castration, docking, the introduction of setons, inclusion of a nerve in a ligature, etc. It may come on a long time after the wound is healed--three or four months. Horses with a nervous, excitable disposition are more predisposed than those of a more sluggish nature. Stallions are more subject to develop tetanus as the result of wounds than geldings, and geldings more than mares.

Symptoms.--The attacks may be acute or subacute. In an acute attack the animal usually dies within four days. The first symptoms which attract the attention of the owner is difficulty in chewing and swallowing, an extension of the head and protrusion over the inner part of the eye of the membrana nictitans, or haw. An examination of the mouth will reveal an inability to open the jaws to their full extent, and the endeavor to do so will produce great nervous excitability and increased spasm of the muscles of the jaw and neck. The muscles of the neck and along the spine become rigid and the legs are moved in a stiff manner. The slightest noise or disturbance throws the animal into increased spasm of all the affected muscles. The tail is usually elevated and held immovable; the bowels become constipated early in the attack. The temperature and pulse are not much changed. These symptoms in the acute type become rapidly aggravated until all the muscles are rigid--in a state of tonic spasm--with a continuous tremor running through them; a cold perspiration breaks out on the body; the breathing becomes painful from the spasm of the muscles used in respiration; the jaws are completely set, eyeballs retracted, lips drawn tightly over the teeth, nostrils dilated, and the animal presents a picture of the most extreme agony until death relieves him. The pulse, which at first was not much affected, will become quick and hard, or small and thready when the spasm affects the muscles of the heart. In the subacute cases the jaws may never become entirely locked; the nervous excitability and rigidity of the muscles are not so great. There is, however, always some stiffness of the neck or spine manifest in turning; the haw is turned over the eyeball when the nose is elevated. It is not uncommon for owners to continue such animals at their work for several days after the first symptoms have been observed. All the symptoms may gradually increase in severity for a period of ten days, and then gradually diminish under judicious treatment, or they may reach the stage wherein all the characteristics of acute tetanus become developed. In some cases, however, we find the muscular cramps almost solely confined to the head or face, perhaps involving those of the neck. In such cases we have complete trismus (lockjaw), and all the head symptoms are acutely developed. On the contrary, we may find the head almost exempt in some cases, and have the body and limbs perfectly rigid and incapable of movement without falling.

Tetanus may possibly be confounded with spinal meningitis, but the character of the spasm-locked jaw, retraction of the eyeballs, the difficulty in swallowing due to spasms of the muscles of the pharynx, and above all, the absence of paralysis, should serve to make the distinction.

Prevention.--When a valuable horse has sustained a wound that it is feared may be followed by tetanus, it is well to administer a dose of tetanus antitoxin. This is injected beneath the skin with a hypodermic syringe. A very high degree of protection may in this way be afforded. This antitoxin should be administered only by a competent veterinarian.

Treatment.--The animal should be placed in a box stall without bedding, as far as possible from other horses. If in a country district, the animal should be put into an outbuilding or shed, where the noise of other animals will not reach it; if the place is moderately dark, it is all the better; in fly time it should be covered with a light sheet. The attendant must be very careful and quiet to prevent all unnecessary excitement and increase of spasm. Tetanus antitoxin appears to be useful as a remedy in some cases, if given in very large quantities early in the disease; otherwise it is useless. Subcutaneous injections of carbolic acid in glycerin and water (carbolic acid 30 grains, glycerin and water each 1 ounce) appear to be useful in some cases. Injections should be given twice daily.

A cathartic, composed of Barbados aloes 6 to 8 drams, with which may be mixed 2 drams of the solid extract of belladonna, should be given at once. This is best given in a ball form; if, however, the animal is greatly excited by the attempt or can not swallow, the ball may be dissolved in 2 ounces of olive oil and thrown on the back of the tongue with a syringe. If the jaws are set, or nearly so, an attempt to administer medicine by the mouth should not be made. In such cases one-quarter of a grain of atropia, with 5 grains of sulphate of morphia, should be dissolved in 1 dram of pure water and injected under the skin. This should be repeated sufficiently often to keep the animal continually under its effect. This will usually mitigate the severity of the spasmodic contraction of the affected muscles and lessen sensibility to pain. Good results may be obtained sometimes by the rectal injection of the fluid extract of belladonna and of cannabis indica, of each 1 dram, every four or six hours. This may be diluted with a quart of milk. When the animal is unable to swallow liquids, oatmeal gruel and milk should be given by injection per rectum to sustain the strength of the animal. A pailful of cool water should be constantly before him, placed high enough for him to reach it without special effort; even if drinking is impossible, the laving of the mouth is refreshing. Excellent success frequently may be obtained by clothing the upper part of the head, the neck, and greater part of the body in woolen blankets kept saturated with very warm water. This treatment should be continued for six or eight hours at a time. It often relaxes the cramped muscles and gives them rest and the animal almost entire freedom from pain; but it should be used every day until the acute spasms have permanently subsided in order to be of any lasting benefit.

Recently subcutaneous injections of brain emulsion have been recommended. It is thought that the tetanus toxin will attach itself to the brain cells so injected and thus free the system of this poison. When it is due to a wound, the wound should be thoroughly cleaned and disinfected with carbolic acid. If from a wound which has healed, an excision of the cicatrix may be beneficial. In all cases it is not uncommon to have a partial recovery followed by relapse when the animal becomes excited from any cause.

RABIES, HYDROPHOBIA, OR MADNESS.

This disease does not arise spontaneously among horses, but is the result of a bite from a rabid animal--generally a dog or cat. The development of the disease follows the bite in from three weeks to three months--very rarely in two weeks. (See also p. 559.)

Symptoms.--The first manifestation of the development of this disease may be an increased excitability and viciousness; very slight noises or the approach of a person incites the animal to kick, strike, or bite at any near object. Very often the horse will bite his own limbs or sides, lacerating the flesh and tearing the skin. The eyes appear staring, bloodshot; the ears are on the alert to catch all sounds; the head is held erect. In some cases the animal will continually rub and bite the locality of the wound inflicted by the rabid animal. This symptom may precede all others. Generally the bowels become constipated and the animal makes frequent attempts at urination, which is painful, and the urine very dark colored. The furious symptoms appear in paroxysms; at other times the animal may eat and drink, although swallowing appears to become painful toward the latter stage of the disease, and may cause renewed paroxysms. The muscles of the limbs or back may be subject to intermittent spasms, or spasmodic tremors; finally, the hind limbs become paralyzed, breathing very difficult, and convulsions supervene, followed by death. The pulse and respirations are increased in frequency from the outset of the attack. Rabies may possibly be mistaken for tetanus. In the latter disease we find tonic spasms of the muscles of the jaws, or stiffness of the neck or back very early in the attack, and evidence of viciousness is absent.

Treatment.--As soon as the true nature of the disease is ascertained the animal should be killed.

Prevention.--When a horse is known to have been bitten by a rabid animal, immediate cauterization of the wound with a red-hot iron may possibly destroy the virus before absorption of it takes place.

PLUMBISM, OR LEAD POISONING.

This disease is not of frequent occurrence. It may be due to the habitual drinking of water which has been standing in leaden conductors or in old paint barrels, etc. It has been met with in enzootic form near smelting works, where, by the fumes arising from the works, lead in the form of oxid, carbonate, or sulphate was deposited on the grass and herbage which the horses ate.

Symptoms.--Lead poisoning produces derangement of the functions of digestion and locomotion, or it may affect the lungs principally. In whatever system of organs the lead is mostly deposited there we have the symptoms of nervous debility most manifest. If in the lungs, the breathing becomes difficult and the animal gets out of breath very quickly when compelled to run. Roaring, also, is very frequently a symptom of lead poisoning. When it affects the stomach, the animal gradually falls away in flesh, the hair becomes rough, the skin tight, and colicky symptoms develop. When the deposit is principally in the muscles, partial or complete paralysis gradually develops. When large quantities of lead have been taken in and absorbed, symptoms resembling epilepsy may result, or coma and delirium develop and prove fatal. In lead poisoning there is seldom any increase in temperature. A blue line forms along the gums of the front teeth, and the breath assumes a peculiarly offensive odor. Lead can always be detected in the urine by chemical tests.

Treatment.--The administration of 2-dram doses of iodid of potassium three times a day is indicated. This will form iodid of lead in the system, which is rapidly excreted by the kidneys. If much muscular weakness or paralysis is present, sulphate of iron in 1-dram doses and strychnia in 2-grain doses may be given twice a day. In all cases of suspected lead poisoning all utensils which have entered into the supply of feed or water should be examined for the presence of soluble lead. If it occurs near lead works, great care must be given to the supply of uncontaminated fodder, etc.

UREMIA.

Uremic poisoning may affect the brain in nephritis, acute albuminuria, or when, from any cause, the functions of the kidneys become impaired or suppressed and urea (a natural product) is no longer eliminated from these organs, causing it to accumulate in the system and give rise to uremic poisoning.

Uremic poisoning is usually preceded by dropsy of the limbs or abdomen; a peculiar, fetid breath is often noticed; then drowsiness, attacks of diarrhea, and general debility ensue. Suddenly extreme stupor or coma develops; the surface of the body becomes cold; the pupils are insensible to light; the pulse slow and intermitting; the breathing labored, and death supervenes. The temperature throughout the disease is seldom increased, unless the disease becomes complicated with acute, inflammatory disease of the brain or respiratory organs, which often occur as a result of the urea in the circulation. Albumen and tube casts may frequently be found in the urine. The disease almost invariably proves fatal.

Treatment must be directed to a removal of the cause.

ELECTRIC SHOCK.

Electric shock, from coming in contact with electric wires, is becoming a matter of rather frequent occurrence, and has a similar effect upon the animal system as a shock from lightning. Two degrees of electric or lightning shock may be observed, one producing temporary contraction of muscles and insensibility, from which recovery is possible, the other killing directly, by producing a condition of nervous and general insensibility. In shocks which are not immediately fatal the animal is usually insensible, the respiration slow, labored, or gasping, the pulse slow, feeble, and irregular, and the pupils dilated and not sensitive, or they may be contracted and sensitive. The temperature is lowered. There may be a tendency to convulsions or spasms. The predominating symptoms are extreme cardiac and respiratory depression.

Treatment.--Sulphate of atropia should be given hypodermically in one-quarter grain doses every hour or two hours until the heart beats are invigorated, the number and fullness of the respirations increased, and consciousness returns. Stimulating injections per rectum may also be useful in arousing the circulation; for this purpose whisky or ammonia water may be used.

DISEASES OF THE HEART, BLOOD VESSELS, AND LYMPHATICS.

By M. R. TRUMBOWER, V. S.

[Revised by Leonard Pearson, B. S., V. M. D.]

ANATOMY AND PHYSIOLOGY OF THE HEART AND BLOOD VESSELS.

(Pls. XX and XXI.)

The heart is a hollow, muscular organ, situated a little to the left of the center of the chest. Its impulse is felt on the left side on account of its location and from the rotary movement of the organ in action. It is cone-shaped, with the base upward; the apex points downward, backward, and to the left side. It extends from about the third to the sixth ribs, inclusive. The average weight is about 7 to 8 pounds. In horses used for speed the heart is relatively larger, according to the weight of the animal, than in horses used for slow work. It is suspended from the spine by the large blood vessels and held in position below by the attachment of the pericardium to the sternum. It is inclosed in a sac, the pericardium, which is composed of a dense fibrous membrane lined by a delicate serous membrane, which is reflected over the heart; the inner layer is firmly adherent to the heart, the outer to the fibrous sac, and there is an intervening space, known as the pericardial space, in which a small amount of serum--a thin translucent liquid--is present constantly.

The heart is divided by a shallow fissure into a right and left side; each of these is again subdivided by a transverse partition into two compartments which communicate. Thus there are four cardiac cavities--the superior, or upper, ones called the auricles; the inferior, or lower, ones the ventricles. These divisions are marked on the outside by grooves, which contain the cardiac blood vessels, and are generally filled with fat.

The right side of the heart may be called the venous side, the left the arterial side, named from the kind of blood which passes through them. The auricles are thin-walled cavities placed at the base, and are connected with the great veins--the venae cavae and pulmonary veins--through which they receive blood from all parts of the body. The auricles communicate with the ventricles each by a large aperture, the auriculo-ventricular orifice, which is furnished with a remarkable mechanism of valves, allowing the transmission of blood from the auricles into the ventricles, but preventing a reverse course. The ventricles are thick-walled cavities, forming the more massive portion of the heart toward the apex. They are separated by a partition, and are connected with the great arteries--the pulmonary artery and the aorta--by which they send blood to all parts of the body. At the mouth of the aorta and at the mouth of the pulmonary artery is an arrangement of valves in each case which prevents the reflux of blood into the ventricles. The auriculo-ventricular valve in the left side is composed of two flaps, hence it is called the bicuspid valve; in the right side this valve has three flaps and is called the tricuspid valve. The flaps which form these valves are connected with a tendinous ring between the auricles and ventricles; and each flap of the auriculo-ventricular valves is supplied with tendinous cords, which are attached to the free margin and under-surface, so as to keep the valves tense when closed--a condition which is produced by the shortening of muscular pillars with which the cords are connected. The arterial openings, both on the right and on the left side, are provided with three-flapped semilunar-shaped valves, to prevent the regurgitation of blood when the ventricles contract. The veins emptying into the auricles are not capable of closure, but the posterior vena cava has an imperfect valve at its aperture.

The inner surface of the heart is lined by a serous membrane, the endocardium, which is smooth and firmly adherent to the muscular structure of the heart. This membrane is continuous with the lining membrane of the blood vessels, and it enters into the formation of the valves.

The circulation through the heart is as follows: The venous blood is carried into the right auricle by the anterior and posterior venae cavae. It then passes through the right auriculo-ventricular opening into the right ventricle, thence through the pulmonary artery to the lungs. It returns by the pulmonary veins to the left auricle, then is forced through the auriculo-ventricular opening into the left ventricle, which propels it through the aorta and its branches into the system, the veins returning it again to the heart. The circulation, therefore, is double, the pulmonary, or lesser, being performed by the right side, and the systemic, or greater, by the left side.

As the blood is forced through the heart by forcible contractions of its muscular walls, it has the action of a force pump, and gives the impulse at each beat, which we call the pulse--the dilatation of the arteries throughout the system. The contraction of the auricles is quickly followed by that of the ventricles, and then a slight pause occurs; this takes place in regular rhythmical order during health.

The action of the heart is governed and maintained by the pneumogastric nerve (tenth pair of cranial nerves); it is the inhibitory nerve of the heart, and regulates, slows, and governs its action. When the nerve is cut, the heartbeats increase rapidly, and, in fact, the organ works without control. When the nerve is unduly irritated the holdback, or inhibitory force, is increased, and the heart slows up in the same measure. The left cavities of the heart, the pulmonary veins, and the aorta, or systemic artery, contain red or florid blood, fit to circulate through the body. The right cavities of the heart, with the venae cavae, or systemic veins, the pulmonary artery, contain dark blood, which must be transmitted through the lungs for renovation.

The arteries, commencing in two great trunks, the aorta and the pulmonary artery, undergo division, as in the branching of a tree. Their branches mostly come off at acute angles, and are commonly of uniform diameter in each case, but successively diminish after and in consequence of division, and in this manner gradually merge into the capillary system of blood vessels. As a general rule, the combined area of the branches is greater than that of the vessels from which they emanate, and hence the collective capacity of the arterial system is greatest at the capillary vessels. The same rule applies to the veins. The effect of the division of the arteries is to make the blood move more slowly along their branches to the capillary vessels, and the effect of the union of the branches of the veins is to accelerate the speed of the blood as it returns from the capillary vessels to the venous trunks.

In the smaller vessels a frequent running together, or anastomosis, occurs. This admits of a free communication between the currents of blood, and must tend to promote equability of distribution and of pressure, and to obviate the effects of local interruption. The arteries are highly elastic, being extensile and retractile both in length and breadth. During life they are also contractile, being provided with muscular tissue. When cut across they present, although empty, an open orifice; the veins, on the other hand, collapse.

In most parts of the body the arteries are inclosed in a sheath formed of connective tissue, but are connected so loosely that, when the vessel is cut across, its ends readily retract some distance within the sheath. Independently of this sheath, arteries are usually described as being formed of three coats, named, from the relative positions, external, middle, and internal. This applies to their structure so far as it is discernible by the naked eye. The internal, serous, or tunica intima, is the thinnest, and is continuous with the lining membrane of the heart. It is made up of two layers--an inner, consisting of a layer of epithelial scales, and an outer, transparent, whitish, highly elastic, and perforated. The middle coat, tunica media, is elastic, dense, and of a yellow color, consisting of nonstriated muscular and elastic fibers, thickest in the largest arteries and becoming thinner in the smaller. In the smallest vessels it is almost entirely muscular. The external coat, tunica adventitia, is composed mainly of fine and closely woven bundles of white connective tissue, which chiefly run diagonally or obliquely around the vessel. In this coat the nutrient vessels, the vasa vasorum, form a capillary network, from which a few penetrate as far as the muscular coat.

The veins differ from arteries in possessing thinner walls, less elastic and muscular tissue, and for the most part a stronger tunica adventitia. They collapse when cut across or when they are empty. The majority of veins are provided with valves; these are folds of the lining membrane, strengthened by fibrous tissue. They favor the course of the blood and prevent its reflux. The nerves which supply both the arteries and the veins come from the sympathetic system. The smaller arteries terminate in the system of minute vessels known as the capillaries, which are interposed between the termination of the arteries and the commencement of the veins. Their average diameter is about one three-thousandth of an inch.

DISEASES OF THE HEART AND BLOOD VESSELS.

In considering diseases of the heart we meet with many difficulties, depending much upon the position which this organ occupies in the animal. The shoulders cover so much of the anterior portion of the chest, and often in very heavy-muscled horses the chest walls are so thick that a satisfactory examination of the heart is attended with difficulty. Diseases of the heart are not uncommon among horses; the heart and its membranes are frequently involved in diseases of the respiratory organs, diseases of the kidneys, rheumatism, influenza, etc. Some of the diseases of this organ are never suspected by the ordinary observer during life, and are so difficult to diagnose with any degree of certainty that we will have to confine ourselves to a general outline, giving attention to such symptoms as may serve to lead to a knowledge of their existence, with directions for treatment, care, etc.

Nervous affections often produce prominent heart symptoms by causing functional disturbance of that organ, which, if removed, will leave the heart restored to perfect vigor and normal action. Organic changes involving the heart or valves, however, usually grow worse and eventually prove fatal. Therefore it is necessary that we arrive at an appreciation of the true nature and causes so that we may be able to form a true estimate of the possibilities for recovery or encouragement for medical treatment.

Disease of the heart may occur at any age, but it is witnessed most frequently in young horses, which, when being trained for fast work, are often subjected to excessive hardship and fatigue. Nervous or timid animals also suffer from such diseases more frequently than those of a sluggish disposition. Any cause which induces a violent or sudden change in the circulation may result in injury to the heart. Symptoms which may frequently denote disease of the heart are difficult breathing or short-windedness, dropsies of the limbs, habitual coldness of the extremities, giddiness or fainting attacks, inability to stand work, although the general appearance would indicate strength and ability, etc.

MYOCARDITIS, OR INFLAMMATION OF THE MUSCULAR STRUCTURE OF THE HEART.

The heart muscle sometimes becomes inflamed as a complication or result of the existence of general or febrile and of infectious diseases. Severe influenza or infectious pneumonia is not infrequently followed by myocarditis. By extension of inflammation of the endocardium or pericardium the muscle of the heart may become involved. Overexertion or especially hard work continued for a long time may cause this muscle to become inflamed.

Symptoms.--Inflammation of the heart muscle is shown by inability to contract forcibly. This results in a rapid but weak, soft pulse and irregular heart sounds. The pulse may be quite irregular as a result of the irregular, tumultuous action of the heart. There is great general weakness, shortness of breath, and rapid respiratory movements. In some cases, where the muscle is very much softened and weakened, or, perhaps when an abscess forms in the wall of the heart, the course of the disease is very rapid and terminates suddenly from paralysis or rupture of the heart.

Alterations.--The heart muscle has a brownish or yellowish, boiled appearance, and is so brittle that it tears easily. There may be a spotted appearance of the muscle from the intense changes in structure in small areas. These small areas may be due to suppuration, in which case they have the characteristics of small abscesses. This last condition is seen in pyemia (blood poisoning). If the disease is of long duration, the fibrous tissue in the wall of the heart may increase to such an extent as to produce an unnatural hardness of the wall.

Treatment.--In this disease the nutrition and strength of the heart should be kept up as much as possible with good food, good care, and heart tonics and stimulants. The horse should be tempted to eat such foods as he will take; he should be kept in an airy box stall; his legs should be well rubbed as often as necessary to keep them warm and bandaged loosely with flannel bandages. Internally the horse may have strychnia, in 2-grain doses twice daily, whisky in 4-ounce doses every two to four hours, digitalis in the form of the tincture in doses of 1 dram every three to six hours. Artificial Carlsbad salts in heaping tablespoonful doses in the feed may be given three times daily for a couple of weeks. Rest is of the greatest importance and should be allowed for a few weeks after recovery seems to be complete.

ENDOCARDITIS, OR INFLAMMATION OF THE LINING MEMBRANE OF THE HEART.

Endocarditis frequently occurs as a complication of rheumatism, some of the specific or zymotic fevers, specific poisoning, etc. This is a more frequent disease among horses than is generally known, and often gives rise to symptoms which at first are obscure and unnoticed.

In influenza we may find the heart becoming involved in the disease, in consequence of the morbid material conveyed through the heart in the blood stream. In view of the fact that many affections in even remote portions of the body may be traced directly to a primary endocardial disease, we shall feel justified in inviting special attention to this disease.

Endocarditis may be acute, subacute, or chronic. In acute inflammation we find a thickening and a roughened appearance of the endocardium throughout the cavities of the heart. This condition may be followed by a coagulation of fibrin upon the inflamed surface, which adheres to it, and by attrition soon becomes worked up into shreddy-like granular elevations. This may lead to a formation of fibrinous clots in the heart and sudden death early in the disease the second or third day.

Subacute endocarditis, which is the most common form, may not become appreciable for several days after its commencement. It is characterized by being confined to one or more anatomical divisions of the heart, and all the successive morbid changes follow each other in a comparatively slow process. Often we would not be led to suspect heart affection were it not for the distress in breathing, which it generally occasions when the animal is exercised, especially if the valves are much involved. When coagula or vegetations form upon the inflamed membrane, either in minute shreds or patches, or when formation of fibrinous clots occurs in the cavity affected, some of these materials may be carried from the cavity of the heart by the blood current into remote organs, constituting emboli that are liable to suddenly plug vessels and thereby interrupt important functions. In the great majority of either acute or subacute grades of endocarditis, whatever the exciting cause, the most alarming symptoms disappear in a week or 10 days, often leaving, however, such changes in the interior lining or valvular structures as to cause impairment in the circulation for a much longer period of time. These changes usually consist of thickening or induration of the inflamed structures. But while the effects of the inflammation in the membrane lining the walls of the ventricles may subside to such a degree as to cause little or no inconvenience, or even wholly disappear, yet after the valvular structures have been involved, causing them to be thicker, less flexible than normal, they usually remain, obstructing the free passage of the blood through the openings of the heart, thereby inducing secondary changes, which take place slowly at first, but ultimately seriously impair the animal's usefulness. What was but a slight obstruction to the circulation during the first few weeks after the subsidence of the cardiac inflammatory attack becomes in process of time so much increased as to induce increased growth in the muscular structure of the heart, constituting hypertrophy of the walls of the ventricles, more particularly of the left, with corresponding fullness of the left auricle and pulmonary veins, thereby producing fullness of the capillaries in the lungs, pressure upon the air cells, difficult or asthmatic breathing--greatly increased in attempts to work--until in a few months many of these cases become entirely disabled for work. Sometimes, too, dropsical effusions in the limbs or into the cavities of the body result from the irregular and deficient circulation. Derangement of the urinary secretion, with passive congestion of the kidneys, may also appear.

Endocardial inflammation is seldom fatal in its early stages, but in many cases the recovery is incomplete, for a large proportion is left with some permanent thickening of the valves, which constitutes the beginning of valvular disease.

Symptoms.--Endocarditis may be ushered in by a chill, with sudden and marked rise in temperature. The pulse rapidly decreases in strength or may become irregular, while the heart beats more or less tumultuously. In the early stages soft-blowing sounds may be heard by placing the ear over the heart on the left side, which correspond in number and rhythm to the heart's action. Excessive pain, though not so great as in acute pleuritis, is manifested when the animal is compelled to trot; very often difficulty in breathing, or shortness of breath, on the slightest exertion develops early in the attack. When the valves are involved in the inflammatory process the visible mucous membranes become either very pale or very dark colored, and fainting may occur when the head is suddenly elevated. When the valves of the right side are affected we may find a regurgitant pulsation in the jugular vein. Occasionally it happens that the heart contracts more frequently than the pulse beats--that is, there may be twice as many contractions of the heart in a minute as there are pulse waves in the arteries. The pulse is always very fast. In some cases we find marked lameness of the left shoulder, and when the animal is turned short to the left side he may groan with pain, and the heart's action become violently excited, although pressure against the chest wall will not produce pain unless roughly applied. The animal is not disposed to eat or drink much; the surface of the body and legs are cold--rarely excessively hot--and frequently the body of the animal is in a subdued tremor. In nearly all cases there is partial suppression of the urinary secretion. The symptoms may continue with very little modification for three or four days, sometimes seven days, without any marked changes. If large fibrinous clots form in the heart the change will be sudden and quickly prove fatal unless they become loosened and are carried away in the circulation; then apoplexy may result from the plugging of arteries too small to give further transmission. If the animal manifests symptoms of improvement, the changes usually are slow and steady until he feels apparently as well as ever, eats well, and moves freely in his stall or yard. When he is taken out, however, the seeming strength often proves deceptive, as he may quickly weaken if urged into a fast gait, the breathing becomes quickened with a double flank movement as in heaves, and all the former symptoms reappear in a modified degree. An examination at this stage may reveal valvular insufficiency, cardiac hypertrophy, or pulmonary engorgement.

In fatal cases of endocarditis death often occurs about the fourth day, from the formation of heart clot or too great embarrassment of the circulation. Endocarditis may be suspected in all cases where plain symptoms of cardiac affection are manifested in animals affected with influenza, rheumatism, or any disease in which the blood may convey septic matter.

Acute endocardial inflammation may be distinguished from pleuritis by the absence of any friction murmur, absence of pain when the chest wall is percussed, and the absence of effusion in the cavity of the chest. It may be distinguished from pericarditis by the absence of the friction sounds and want of an enlarged area of dullness on percussion.

Treatment.--The objects to be attained by treatment will be to remove or mitigate as much as possible the cause inducing the disease; to find a medicine which will lessen the irritability of the heart without weakening it; and, last, to maintain a free urinary secretion and prevent exudation and hypertrophy. So long as there is an increase of temperature, with some degree of scantiness of the urine, it may be safe to believe that there is some degree of inflammatory action existing in the cardiac structures, and as long as any evidence of inflammatory action remains, however moderate in degree, there is a tendency to increase or hypertrophy of the connective tissue of the heart or valves, thereby rendering it almost certain that the structural changes will become permanent unless counteracted by persistent treatment and complete rest.

The tincture of digitalis, in 20-drop doses, repeated every hour, is perhaps the most reliable agent we know to control the irritability of the heart, and this also has a decided influence upon the urinary secretion. After the desired impression upon the heart is obtained the dose may be repeated every two or three hours, or as the case may demand. Tincture of strophanthus, in 2-dram doses, will quiet the tumultuous action of the heart in some cases where the digitalis fails. Bleeding, blistering, and stimulating applications to the chest should be avoided. They serve to irritate the animal and can do no possible good. Chlorate of potassium in 2-dram doses may be given in the drinking water every four hours for the first five or six days, and then be superseded by the nitrate of potassium in half-ounce doses for the following week or until the urinary secretion becomes abnormally profuse. Where the disease is associated with rheumatism, 2-dram doses of salicylate of soda may be substituted for the chlorate of potassium. To guard against chronic induration of the valves, the iodid of potassium, in 1 to 2 dram doses, should be given early in the disease and may be repeated two or three times a day for several weeks. When chronic effects remain after the acute stage has passed this drug becomes indispensable.

When dropsy of the limbs develops, it is due to weakened circulation or functional impairment of the kidneys. When there is much weakness in the action of the heart, or general debility is marked, the iodid of iron, in 1-dram doses, combined with hydrastis, 3 drams, may be given three times a day. Arsenic, in 5-grain doses twice a day, will give excellent results in some cases of weak heart associated with difficult breathing. In all cases absolute rest and warm stabling, with comfortable clothing, become necessary, and freedom from work should be allowed for a long time after all symptoms have disappeared.

PERICARDITIS, OR INFLAMMATION OF THE SAC INCLOSING THE HEART.

Causes.--Pericarditis may be induced by cold and damp stabling, exposure and fatigue, from wounds caused by broken ribs, etc. Generally, however, it is associated with an attack of influenza, rheumatism, pleuritis, etc.

Symptoms.--Usually the disease manifests itself abruptly by a brief stage of chills coincident with pain in moving, a short painful cough, rapid and short breathing, and high temperature, with a rapid and hard pulse. In the early stages of the disease the pulse is regular in beat; later, when there is much exudation present in the pericardial sac, the heartbeat becomes muffled, and may be of a double or rebounding character. By placing the ear against the left side of the chest behind the elbow a rasping sound may be heard, corresponding to the frequency of the heartbeat. This is known as a friction sound. Between the second and fourth days this sound may disappear, due to a distension of the pericardium by an exudate or serous effusion. As soon as this effusion partly fills the pericardium, percussion will reveal an abnormally increased area of dullness over the region of the heart, the heartbeats become less perceptible than in health, and in some cases a splashing or flapping sound may become audible.

If the effusion becomes absorbed, the friction sound usually recurs for a short time; this friction may often be felt by applying the hand to the side of the chest. In a few cases clonic spasms of the muscles of the neck may be present. In acute pericarditis, when the effusion is rapid and excessive, the animal may die in a few days or recovery may begin equally as early. In subacute or in chronic cases the effusion may slowly become augmented until the pressure upon the lungs and interference with the circulation become so great that death will result. Whether the attack is acute, subacute, or chronic, the characteristic symptoms which will guide us to a correct diagnosis are the friction sound, which is always synchronous with the heart's action, the high temperature with hard, irritable pulse, and, in cases of pericardial effusion, the increased area of dullness over the cardiac region. When the disease is associated with influenza or rheumatism, some of the symptoms may be obscure, but a careful examination will reveal sufficient evidence upon which to base a diagnosis. When pericarditis develops as a result of or in connection with pleuritis, the distinction may not be very clearly definable, neither will many recover. When it results from a wound or broken rib, it almost invariably proves fatal.

Pathology.--Pericarditis may at all times be regarded as a very serious affection. At first we will find an intense injection or accumulation of blood in the vessels of the pericardium, giving it a red and swollen appearance, during which we have the friction sound. In 24 to 48 hours this engorgement is followed by an exudation of sero-fibrinous fluid, the fibrinous portion of which may soon form a coating over the internal surface of the pericardial sac, and may ultimately form a union of the opposing surfaces. Generally this adhesion will only be found to occupy a portion of the surfaces. As the serous or watery portion of this effusion is absorbed, the distinctness of the friction sound recurs, and may remain perceptible in a varied degree for a long time. When the serous effusion is very great, the pressure exerted upon the heart weakens its action, and may produce death soon; when it is not so great, it may cause dropsies of other portions of the body. When the adhesions of the pericardial sac to the body of the heart are extensive, they generally lead to increased growth, or hypertrophy, of the heart, with or without dilatation of its cavities; when they are but slight, they may not cause any inconvenience.

Treatment.--In acute or subacute pericarditis the tincture of digitalis may be given in 20 to 30 drop doses every hour until the pulse and temperature become reduced. Whisky or carbonate of ammonia may be given regularly as stimulants. Bandages should be applied to the legs; if the legs are very cold, tincture of capsicum should be first applied; the body should be warmly clothed in blankets, to promote perspiration. When the suffering from pain is very severe, 10 grains of morphin may be given by the mouth once or twice a day; nitrate of potassium, half an ounce, in drinking water, every six hours; after the third day, iodid of potassium, in 2-dram doses, may be substituted. Cold packs to the chest in the early stages of the disease may give marked relief, or, late in the disease, smart blisters may be applied to the sides of the chest with benefit. If the disease becomes chronic, iodid of iron and gentian to support the strength will be indicated, but the iodid of potassium, in 1 or 2 dram doses, two or three times a day, must not be abandoned so long as there is an evidence of effusion or plastic exudate accumulating in the pericardial sac. Where the effusion is great and threatens the life of the patient, tapping by an expert veterinarian may save the animal.

VALVULAR DISEASE OF THE HEART.

Acute valvular disease can not be distinguished from endocarditis, and chronic valvular affections are generally the result of endocardial inflammation. The valves of the left side are the most subject--the bicuspid or mitral and the aortic or semilunar. The derangement may consist of mere inflammation and swelling, or the edges of the valves may become covered by the organization of the exudation, thus narrowing the passage. Valvular obstruction and adhesions may occur or the tendinous cords may be lengthened or shortened, thus obstructing the orifices and permitting the regurgitation of blood. In protected cases the fibrous tissue of the valves may be transformed into fibro-cartilage or bone, or there may be deposits of salts of lime beneath the serous membrance, which may terminate in ulceration, rupture, or fissures. Sometimes the valves become covered by fibrinous, fleshy, or hard vegetations, or excrescences. In cases of considerable dilatation of the heart there may be atrophy and shrinking of the valves.

Symptoms.--Valvular disease may be indicated by a venous pulse, jerking pulse, intermittent pulse, irregular pulse; palpitation; constant abnormal fullness of the jugular veins; difficulty of breathing when the animal becomes excited or is urged out of a walk or into a fast trot; attacks of vertigo; congestion of the brain; dropsical swelling of the limbs. A blowing, cooing, or bubbling murmur may sometimes be heard by placing the ear over the heart on the left side of the chest.

Hypertrophy, or dilatation, or both, usually follow valvular disease.

Treatment.--When the pulse is irregular or irritable, tonics, such as preparations of iron, gentian, and ginger, may be given. When the action of the heart is jerking or violent, 20 to 30 drop doses of tincture of digitalis or of veratrum viride may be given until these symptoms abate. As the disease nearly always is the result of endocarditis, the iodid of potassium and general tonics, sometimes stimulants, when general debility supervenes, may be of temporary benefit. Very few animals recover or remain useful for any length of time after once marked organic changes have taken place in the valvular structure of the heart.

ADVENTITIOUS GROWTHS IN THE HEART.

Fibrous, cartilaginous, and bony formations have been observed in some rare instances in the muscular tissue. Isolated calcareous masses have sometimes been embedded in the cardiac walls. Fibrinous coagula and polypous concretions may be found in the cavities of the heart. The former consist of coagulated fibrin, separated from the mass of blood, of a whitish or yellowish white color, translucent, of a jellylike consistence, and having a nucleus in the center. They may slightly adhere to the surface of the cavity, from which they can easily be separated without altering the structure of the endocardium. They probably result from an excess of coagulability of fibrin, which is produced by an organization of the lymph during exudation. They are usually found in the right auricle and ventricle.

Polypous concretions are firmer than in the preceding, more opaque, of a fibrous texture, and may be composed of successive layers. In some instances they are exceedingly minute, while in others they almost fill one or more of the cavities. Their color is usually white, but occasionally red from the presence of blood. They firmly adhere to the endocardium, and when detached from it give it a torn appearance. Occasionally, a vascular communication seems to exist between them and the substance of the heart. They may be the result of fibrinous exudation from inflammation of the inner surface of the heart or the coagulation of a portion of the blood which afterwards contracts adhesion with the heart. These concretions prove a source of great inconvenience and often danger, no matter how formed. They cause a diminution in the cavity in which they are found, thus narrowing the orifice through which the blood passes, or preventing a proper coaptation of the valves, which may produce most serious valvular disease.

Symptoms.--These are frequently uncertain; they may, however, be suspected when the action of the heart suddenly becomes embarrassed with irregular and confused pulsations, great difficulty of breathing, and the usual signs dependent upon the imperfect arterialization of the blood.

Treatment.--Stimulants, whisky, or carbonate of ammonia may be of service.

PALPITATION OF THE HEART.

This is a tumultuous and usually irregular beating of the heart. It may be due to a variety of causes, both functional and organic. It may occur as a result of indigestion, fright, increased nervousness, sudden excitement, excessive speeding, etc. (See "Thumps," p. 225.)

Symptoms.--The heart may act with such violence that each beat may jar the whole body of the animal; very commonly it may be heard at a short distance away from the animal. It can usually be traced very readily to the exciting cause, which we may be able to avoid or overcome in the future and thereby obviate subsequent attacks. Rest, a mild stimulant, or a dose or two of tincture of digitalis or opium will generally give prompt relief. When it is due to organic impairment of the heart it must be regarded as a symptom, not as a matter of primary specific treatment.

SYNCOPE, OR FAINTING.

Actual fainting rarely occurs among horses. It may, however, be induced by a rapid and great loss of blood, pain of great intensity, a mechanical interference with the circulation of the brain, etc.

Symptoms.--Syncope is characterized by a decrease or temporary suspension of the action of the heart and respiration, with partial or total loss of consciousness. It generally occurs suddenly, though there may be premonitory symptoms, as giddiness, or vertigo, dilated pupil, staggering, blanching of the visible mucous membranes, a rapidly sinking pulse, and dropping to the ground. The pulse is feeble or ceases to beat; the surface of the body turns cold; breathing is scarcely to be perceived, and the animal may be entirely unconscious. This state is uncertain in duration--generally it lasts only a few minutes; the circulation becomes restored, breathing becomes more distinct, and consciousness and muscular strength return. In cases attended with much hemorrhage or organic disease of the heart, the fainting fit may be fatal; otherwise it will prove but a transient occurrence. In paralysis of the heart the symptoms may be exactly similar to syncope. Syncope may be distinguished from apoplexy by the absence of stertorous breathing and lividity of the visible mucous membranes.

Treatment.--Dash cold water on the head; administer a stimulant--4 ounces of whisky or half an ounce of carbonate of ammonia. Prevent the animal from getting up too soon, or the attack may immediately recur. Afterwards, if the attack was due to weakness from loss of blood, impoverished blood, or associated with debility, general tonics, rest, and nourishing food are indicated.

HYPERTROPHY OF THE HEART, OR CARDIAC ENLARGEMENT.

Hypertrophy of the heart implies augmentation of bulk in its muscular substance, with or without dilatation or contraction of its cavities. It may exist with or without other cardiac affections. In valvular disease or valvular insufficiency hypertrophy frequently results as a consequence of increased demand for propelling power. The difficulties with which it is most frequently connected are dilatation and ossification of the valves. It may also occur in connection with atrophied kidneys, weak heart, etc. It may be caused by an increased determination of blood to the organ or from a latent form of myocarditis, and it may arise from a long-continued increase of action dependent upon nervous disease. All the cavities of the heart may have their walls hypertrophied or the thickening may involve one or more. While the wall of a ventricle is thickened, its cavity may retain its normal size (simple hypertrophy) or be dilated (eccentric hypertrophy), or it may be contracted (concentric hypertrophy). Hypertrophy of both ventricles increases the length and breadth of the heart. Hypertrophy of the left ventricle alone increases its length; of the right ventricle alone increases its breadth toward the right side. Hypertrophy with dilatation may affect the chambers of the heart conjointly or separately. This form is by far the most frequent variety of cardiac enlargement. When the entire heart is affected, it assumes a globular appearance, the apex being almost obliterated and situated transversely in the chest. The bulk may become three or four times greater than the average heart.

Symptoms.--In hypertrophy of the heart, in addition to the usual symptoms manifested in organic diseases of the heart, there is a powerful and heaving impulse at each beat, which may be felt on the left side, often also on the right. These pulsations are regular, and when full and strong at the jaw there is a tendency to active congestion of the capillary vessels, which frequently give rise to local inflammation, active hemorrhage, etc. If the pulse is small and feeble at the jaw, we may conclude that there is some obstacle to the escape of the blood from the left ventricle into the aorta, which has given rise to the hypertrophy. In case of hypertrophy with dilatation, the impulse is not only powerful and heaving, but it is diffused over the whole region of the heart, and the normal sounds of the heart are greatly increased in intensity. Percussion reveals an enlarged area of dullness, while the impulse is usually much stronger than normal.

Dropsy of the pericardium will give the same wide space of dullness, but the impulse and sound are lessened. An animal with a moderate degree of enlargement may possibly live a number of years and be capable of ordinary work; it depends largely upon concomitant disease. As a rule, an animal affected with hypertrophy of the heart will soon be incapacitated for work, and becomes useless and incurable.

Treatment.--If the cause can be discovered and is removable, it should be done. The iodid of potassium, in cases of valvular thickening, may be of some benefit if continued for a sufficient length of time; it may be given in 2-dram doses, twice a day, for a month or more. The tincture of digitalis may be given, in cases where the pulse is weak, in doses of 2 teaspoonfuls three times daily. This remedy should not be continued if the pulse becomes irregular. General tonics, freedom from excitement or fatigue, avoidance of bulky food, good ventilation, etc., are indicated.

DILATATION OF THE HEART.

This is an enlargement, or stretching, of the cavities of the heart, and may be confined to one or extend to all. Two forms of dilatation may be mentioned--simple dilatation, where there is normal thickness of the walls, and passive, or attenuated, dilatation, where the walls are simply distended or stretched out without any addition of substance.

Causes.--Any cause producing constant and excessive exertion of the heart may lead to dilatation. Valvular disease is the most frequent cause. General anemia predisposes to it by producing relaxation of muscular fiber. Changes in the muscular tissue of the heart walls, serous infiltration from pericarditis, myocarditis, fatty degeneration and infiltration, and atrophy of the muscular fibers may all lead to dilatation.

Symptoms.--The movements of the heart are feeble and prolonged, a disposition to staggering or vertigo, dropsy of the limbs, very pale or very dark-colored membranes, and difficult breathing on the slightest excitement.

Treatment.--General tonics, rich feed, and rest.

FATTY DEGENERATION OF THE HEART.

Fatty degeneration may involve the whole organ, or may be limited to its walls, or even to circumscribed patches. The latter is situated at the exterior, and gives it a mottled appearance. When generally involved it is flabby or flaccid, and in extreme cases collapses when emptied or cut. Upon dissection the interior of the ventricles is observed to be covered with buff-colored spots of a singular zigzag form. This appearance may be noticed beneath the pericardium, and pervading the whole thickness of the ventricular walls, and in extreme cases those of the fleshy columns in the interior of the heart. These spots are found to be degenerated muscular fibers and colonies of oil globules. Fatty degeneration is often associated with other morbid conditions of the heart, such as obesity, dilatation, rupture, aneurism, etc. It may be connected with fatty diseases of other organs, such as the liver, kidneys, etc. When it exists alone its presence is seldom suspected previous to death. It may be secondary to hypertrophy of the heart, to myocarditis, or to pericarditis. It may be due to deteriorated conditions of the blood in wasting diseases, excessive hemorrhages, etc., or to poisoning with arsenic and phosphorus.

Symptoms.--The most prominent symptoms of fatty degeneration are a feeble action of the heart, a remarkably slow pulse, general debility, and attacks of vertigo. It may exist for a long time, but is apt to terminate suddenly in death upon the occurrence of other diseases, surgical operations, etc. It may involve a liability to sudden death from rupture of the ventricular walls.

Treatment.--Confinement in feed to oats, wheat or rye bran, and timothy hay. Twenty drops of sulphuric acid may be given in drinking water three times a day, and hypophosphite of iron in 2-dram doses, mixed with the feed, twice a day. Other tonics and stimulants as they may be indicated.

RUPTURE OF THE HEART.

This may occur as the result of some previous disease, such as fatty degeneration, dilatation with weakness of the muscular walls, etc. It may be caused by external violence, a crushing fall, pressure of some great weight, etc. Usually death follows a rupture very quickly, though an animal may live for some time when the rent is not very large.

WEAKNESS OF THE HEART.

This may arise from general debility, the result of exhausting disease, overwork, or heart strain, or loss of blood. It is indicated by a small, feeble, but generally regular pulse, coldness of the body, etc.

Treatment should be directed to support and increase the strength of the animal by tonics, rest, and nutritious feed. Carbonate of ammonia may be given to stimulate the heart's action and to prevent the formation of heart clot.

CONGESTION OF THE HEART

Congestion, or an accumulation of the blood in the cavities of the heart, may occur in consequence of fibrinous deposits interfering with the free movements of the valves, usually the product of endocarditis or as a result of excessive muscular exertion.

Symptoms are great difficulty of breathing, paleness of the visible mucous membranes, great anxiety, frequently accompanied by a general tremor and cold perspiration, followed by death. It usually results in death very quickly.

CYANOSIS OF NEWBORN FOALS.

This is a condition sometimes found in foals immediately after birth, and is due to nonclosure of the foramen ovale, which allows a mixture of the venous with the arterial blood in the left cavities of the heart. It is characterized by a dark purple or bluish color of the visible mucous membranes, shortness of breath, and a general feebleness. Foals thus affected generally live only a few hours after birth.

DISEASES OF ARTERIES, OR ARTERITIS AND ENDARTERITIS.

Inflammation of arteries is rarely observed in the horse as a primary affection. Direct injuries, such as blows, may produce a contusion and subsequent inflammation of the wall of an artery; severe muscular strain may involve an arterial trunk; hypertrophy of the heart, by increasing arterial tension, may result in the production of a general endarteritis. Septic infection may affect the inner coat and ultimately involve all three, or it may be the result of an inflammation in the vicinity of the vessels, etc. Inflammation of arteries, whatever the cause may be, often leads to very serious results in the development of secondary changes in their walls. Arteritis may be acute, subacute, or chronic; when the inner coat alone is affected it is known as endarteritis.

Symptoms.--Arteritis is characterized by a painful swelling along the inflamed vessel, throbbing pulse, coldness of the parts supplied by the inflamed vessel, sometimes the formation of gangrenous sloughs, suppuration, abscess, etc. In an inflammation of the iliac arteries we find coldness and excessive lameness or paralysis of one or both hind limbs.

Pathology.--In acute arteritis we find swelling along the vessel, loss of elasticity, friability, and thickening of the walls; a roughness and loss of gloss of the inner coat, with the formation of coagula or pus in the vessel. Subacute or chronic arteritis may affect only the outer coat (periarteritis), both the outer and middle coat, or the inner coat alone (endarteritis); and by weakening the respective coats leads to rupture, aneurism, or to degenerations, such as bony, calcareous, fatty, atheromatous, etc. It may also lead to sclerosis or increase of fibrous tissue, especially in the kidneys, when it may result in the condition known as arterio-capillary fibrosis. Chronic endarteritis is fruitful in the production of thrombus and atheroma. Arteritis may be limited to single trunks or it may affect, more or less, all the arteries of the body. Arteries which are at the seat of chronic endarteritis are liable to suffer degenerative changes, consisting chiefly of fatty degeneration, calcification, or the breaking down of the degenerated tissue, and the formation of erosions or ulcerlike openings in the inner coat. These erosions are frequently called atheromatous ulcers, and fragments of tissue from these ulcers may be carried into the circulation, forming emboli. Fibrinous thrombi are apt to form upon the roughened surface of the inner coat or upon the surface of the erosions.

Fatty degeneration and calcification of the middle and outer coats may occur, and large, hard, calcareous plates project inward, upon which thrombi may form or may exist in connection with atheroma of the inner coat. When there is much thickening and increase of new tissue in the wall of the affected artery it may encroach upon the capacity of the vessel, and even lead to obliteration. This is often associated with interstitial inflammation of glandular organs.

Treatment.--Carbonate of potassium in 1-dram doses, to be given in 4 ounces liquor acetate of ammonia every six hours; scalded bran sufficient to produce loosening of the bowels, and complete rest; externally, applications of hot water or hot hop infusion.

ATHEROMA.

Atheroma is a direct result of an existing chronic endarteritis, the lining membrane of the vessels being invariably involved to a greater or less degree. It is most frequently found in the arteries, although the veins may develop an atheromatous condition when exposed to any source of prolonged irritation. Atheroma may affect arteries in any part of the body; in some instances almost every vessel is diseased, in others only a few, or even parts of one vessel. It is a very common result of endocarditis extending into the aorta, which we find perhaps the most frequent seat of atheroma. As a result of this condition the affected vessel becomes impaired in its contractile power, loses its natural strength, and, in consequence of its inability to sustain its accustomed internal pressure, undergoes in many cases dilatation at the seat of disease, constituting aneurism. In an atheromatous vessel, calcareous deposits soon occur, which render it rigid, brittle, and subject to ulceration or rupture. In such vessels the contractility is destroyed, the middle coat atrophied and beyond repair. Atheroma in the vessels of the brain is a frequent cause of cerebral apoplexy. No symptoms are manifested by which we can recognize this condition during life.

CONSTRICTION OF AN ARTERY.

This is usually the result of arteritis, and may partly or wholly be impervious to the flow of blood. When this occurs in a large vessel it may be followed by gangrene of the parts; usually, however, collateral circulation will be established to nourish the parts previously supplied by the obliterated vessel. In a few instances constriction of the aorta has produced death.

ANEURISM.

Aneurism is usually described as true or false. True aneurism is a dilatation of the coats of an artery over a larger or smaller part of its course. Such dilatations are usually due to chronic endarteritis and atheroma. False aneurism is formed after a puncture of an artery by a dilatation of the adhesive lymph by which the puncture was united.

Symptoms.--If the aneurism is seated along the neck or a limb it appears as a tumor in the course of an artery and pulsating with it. The tumor is round, soft, and compressible, and yields a peculiar fluctuation upon pressure. By applying the ear over it a peculiar purring or hissing sound may sometimes be heard. Pulsation, synchronous with the action of the heart, is the diagnostic symptom. It is of a slow, expansive, and heavy character, as if the whole tumor were enlarging under the hand. Aneurisms seated internally may occupy the cavity of the cranium, chest, or abdomen. As regards the first, little is known during life, for all the symptoms which they produce may arise from other causes. Aneurism of the anterior aorta may be situated very closely to the heart or in the arch, and it is very seldom that we can distinguish it from disease of the heart. The tumor may encroach upon the windpipe and produce difficulty in breathing, or it may produce pressure upon the vena cava or the thoracic duct, obstructing the flow of blood and lymph. In fact, whatever parts the aneurism may reach or subject to its pressure, may have their functions suspended or disturbed. When the tumor in the chest is large, we generally find much irregularity in the action of the heart; the superficial veins of the neck are distended, and there is usually dropsical swelling under the breast and of the limbs. There may be a very troublesome cough without any evidence of lung affection. Sometimes pulsation of the tumor may be felt at the lower part of the neck where it joins the chest. When the aneurism occurs in the posterior aorta no diagnostic symptoms are appreciable; when it occurs in the internal iliac arteries an examination per rectum will reveal it.

There is one form of aneurism which is not infrequently overlooked, affecting the anterior mesenteric artery, primarily induced by a worm--Strongylus vulgaris. This worm produces an arteritis, with atheroma, degeneration, and dilatation of the mesenteric arteries, associated with thrombus and aneurism. The aneurism gives rise to colic, which appears periodically in a very violent and often persistent type. Ordinary colic remedies have no effect, and after a time the animal succumbs to the disease. In all cases of animals which are habitually subject to colicky attacks, parasitic aneurism of the anterior mesenteric artery may be suspected. (See p. 92.)

Pathology.--Aneurisms may be diffuse or sacculated. The diffuse consists in a uniform dilatation of all the coats of an artery, so that it assumes the shape of a cylindrical swelling. The wall of the aneurism is atheromatous, or calcified; the middle coat may be atrophied. The sacculated, or circumscribed, aneurism consists either in a dilatation of the entire circumference of an artery over a short portion of its length, or in a dilatation of only a small portion of one side of the wall. Aneurism may become very large; as it increases in size it presses upon and causes the destruction of neighboring tissues. The cavity of the aneurismal sac is filled with fluid or clotted blood or with layers of fibrin which adhere closely to its wall. Death is produced usually by the pressure and interference of the aneurism with adjoining organs or by rupture. In worm aneurism we usually find large thrombi within the aneurismal dilatation of the artery, which sometimes plug the whole vessel or extend into the aorta. Portions of this thrombus, or clot, may be washed away and produce embolism of a smaller artery. The effect in either case is to produce anemia of the intestinal canal, serous or bloody exudation in its walls, which leads to paralysis of the intestine and resultant colicky symptoms.

Treatment.--The only treatment advisable is to extirpate or ligate the tumor above and below.

RUPTURE OF AN ARTERY.

Endarteritis, with its subsequent changes in the walls of arteries, is the primary cause of rupture in the majority of instances. The rupture may be partial, involving only one or two coats, and will then form an aneurism. If complete, it may produce death when it involves a large vessel, especially if it is situated in one of the large cavities permitting an excessive escape of blood. Rupture may be produced by mechanical violence or accident.

Symptoms.--In fatal rupture, associated with profuse bleeding, the animal becomes weak, the visible mucous membranes become blanched, the breathing hurried or gasping, pupils dilated, staggering in gait, syncope, death. When the hemorrhage is limited the symptoms may not become noticeable; if it is near the surface of the body a round or diffuse swelling or tumor may form, constituting a hygroma. If the rupture is associated with an external wound, the bleeding artery should be ligated, or where a bandage is applicable, pressure may be applied by tight bandaging. As a secondary result of rupture of an artery we may have formation of abscess, gangrene of a part, etc.

Treatment.--When rupture of a deep-seated artery is suspected, large doses of fluid extract of ergot may be given to produce contraction of the blood vessels. Tannin and iron are also useful. The animal should be allowed to have as much water as he desires. Afterwards stimulants and nourishing feed are indicated.

THROMBUS AND EMBOLISM.

By thrombosis is generally understood the partial or complete closure of a vessel by a morbid product developed at the site of the obstruction. The coagulum, which is usually fibrinous, is known as a thrombus. The term "embolism" designates an obstruction caused by any body detached and transported from the interior of the heart or of some vessel. Thrombi occur as the result of an injury to the wall of the vessel or may follow its compression or dilatation; they may result from some alteration of the wall of the vessel by disease or by the retardation of the circulation. These formations may occur during life, in the heart, arteries, veins, or in the portal system. When a portion of fibrin coagulates in one of the arteries and is carried along by the circulation, it will be arrested, of course, in the capillaries, if not before; when in the veins, it may not be stopped until it reaches the lungs; and when in the portal system the capillaries of the liver will prevent its further progress. The formation of thrombi may act primarily by causing partial or complete obstruction, and, secondarily, either by larger or smaller fragments becoming detached from their end and by being carried along by the circulation of the blood to remote vessels, embolism; or by the coagulum becoming softened and converted into pus, constituting suppurative phlebitis. These substances occur most frequently in those affections characterized by great exhaustion or debility, such as pneumonia, purpura hemorrhagica, endocarditis, phlebitis, puerperal fever, hemorrhages, etc. These concretions may form suddenly and produce instantaneous death by retarding the blood current, or they may arise gradually, in which case the thrombi may be organized and attached to the walls of the heart, or they may soften, and fragments of them (emboli) may be carried away. The small, wartlike excrescences occurring sometimes in endocarditis may occasionally form a foundation on which a thrombi may develop.

Symptoms.--When heart clot, or thrombus, exists in the right side, the return of blood from the body and the aeration in the lungs is impeded, and if death occurs, it is owing to syncope rather than to strangulation in pulmonary respiration. There will be hurried and gasping breathing, paleness and coldness of the surface of the body, a feeble and intermittent or fluttering pulse, and fainting. When a fibrinous coagulum is carried into the pulmonary artery from the right side of the heart, the indications are a swelling and infiltration of the lungs and pulmonary apoplexy. When the clot is situated in the left cavities of the heart or in the aorta, death, if it occurs, takes place either suddenly or at the end of a few hours from coma.

Pathology.--When a coagulum is observed in the heart it may become a question whether it was formed during life or after death. The loose, dark coagula so often found after death are polypi. If the deposition has taken place during the last moments of life, the fibrin will be isolated and soft, but not adherent to the walls; if it be isolated, dense, and adherent or closely intertwined with the muscles of the papillae and tendinous cords, the deposition has occurred more or less remote from the act of dying. Occasionally the fibrin may be seen lining one of the cavities of the heart, like a false endocardium, or else forming an additional coat to the aorta or other large vessels without producing much obstruction. Thrombi, in some instances, soften in their centers, and are then observed to contain a puslike substance. If this softening has extended considerably, an outer shell, or cyst, only may remain. The sources of danger exist not only in the interruption of the circulation of the blood, but also in a morbid state of the system, produced by the disturbed nutrition of a limb or organ, as well as the mingling of purulent and gangrenous elements with the blood.

Treatment.--The urgent symptoms should be relieved by rest, stimulants, and the use of agents which will act as solvents to the fibrinous clots. Alkalis are specially useful for this purpose. Carbonate of ammonia may be administered in all cases of thrombus, and should be continued for a long time in small doses several times a day. In cases of great debility associated with a low grade of fever, stimulants and tonics, and nitro-muriatic acid as an antiseptic, may be beneficial.

DISEASES OF VEINS, OR PHLEBITIS.

Inflammation of veins may be simple or diffuse. In simple phlebitis the disease of the vein is confined to a circumscribed or limited portion of a vein; in diffuse it involves the vein for a long distance; it may even extend from a limb or foot to the heart.

Causes.--Phlebitis may be induced by contusions or direct injuries, an extension of inflammation from surrounding tissue, such as in abscess, formation of tumor, or malignant growth. It is often due to embolism of infective material, gangrenous matter, etc. Blood-letting from the jugular vein is occasionally followed by dangerous phlebitis.

Symptoms.--The symptoms vary according to the extent and severity of the inflammation. In most cases the vein is swollen, thickened, and indurated to such a degree as to resemble an artery. A diffused swelling, with great tenderness, may extend along the affected vessel and the animal manifest all the symptoms connected with acute fever and general functional disturbance.

Pathology.--The disease is only serious when large veins are affected. The coats undergo the same changes as in arteritis; clots of blood and lymph plug the inflamed vessel, and, if the inflammatory process continues, these are converted into pus, which ruptures the vessel and produces a deep abscess; or it may be carried away in the circulation and produce metastatic abscess in the lungs or other remote organs. In mild cases the clots may become absorbed and the vessel restored to health. Phlebitis in the course of the veins of the limbs frequently leads to numerous abscesses, which may be mistaken for farcy ulcerations. A very common result of phlebitis is an obliteration of the affected portion of the vein, but as collateral circulation is readily established this is seldom of any material inconvenience.

Treatment.--Phlebitis should be treated by the application of a smart blister along the course of the inflamed vessel; early opening of any abscesses which may form; the animal should have complete rest, and the bowels be kept loose with bran mashes. When the fever runs high, half-ounce doses of nitrate of potassium may be given in the drinking water, which may be changed in two or three days for 1-dram doses of the iodid of potassium. If the animal becomes debilitated, carbonate of ammonia, 1 dram, and powdered gentian, 3 drams, may be given every six hours.

VARICOSE VEINS, VARIX, OR DILATATION OF VEINS.

This may be a result of weakening of the coats from inflammatory disease and degeneration. It may also be due to mechanical obstruction from internal or external sources. It is sometimes found in the vein which lies superficial over the inside of the hock joint, and may be due to the pressure of a spavin. Occasionally it may be observed in stallions, which are more or less subject to varicocele, or dilatation of the veins of the testicular cord. Hemorrhoidal veins, or piles, are occasionally met with, generally in horses which run at pasture. Varicose veins may ulcerate and form an abscess in the surrounding tissues, or they may rupture from internal blood pressure and the blood form large tumors where the tissues are soft.

Treatment.--Stallions which manifest a tendency to varicocele should wear suspensory bags when they are exercised. Piles may often be reduced by astringent washes--tea made from white-oak bark or a saturated solution of alum. The bowels should be kept loose with bran mashes and the animal kept quiet in the stable. When varicose veins exist superficially and threaten to produce inconvenience, they may be ligated above and below and thus obliterated. Sometimes absorption may be induced by constant bandages.

AIR IN VEINS, OR AIR EMBOLISM.

It was formerly supposed that the entrance of air into a vein at the time of the infliction of a wound or in blood-letting was extremely dangerous and very often produced sudden death by interfering with the circulation of the blood through the heart and lungs. Danger from air embolism is exceedingly doubtful, unless great quantities were forced into a large vein by artificial means.

PURPURA HEMORRHAGICA.

Purpura hemorrhagica usually occurs as a sequel to debilitating diseases, such as strangles, influenza, etc. It may, however, arise in the absence of any previous disease in badly ventilated stables, among poorly fed horses, and in animals subject to exhausting work and extreme temperatures. The disease is probably due to some as yet undiscovered infectious principle. Its gravity does not depend so much upon the amount of blood extravasated as it does upon the disturbance or diminished action of the vasomotor centers.

Symptoms.--This disease becomes manifested by the occurrence of sudden swellings on various parts of the body, on the head or lips, limbs, abdomen, etc. These swellings may be diffused or very markedly circumscribed, though in the advanced stages they cover large areas. They pit on pressure and are but slightly painful to the touch. The limbs may swell to a very large size, the nostrils may become almost closed, and the head and throat may swell to the point of suffocation. The swellings not infrequently disappear from one portion of the body and develop on another, or may recede from the surface and invade the intestinal mucous membrane. The mucous lining of the nostrils and mouth show more or less dark-red or purple spots. There may be a discharge of blood-colored serum from the nostrils; the tongue may be swollen so as to prevent eating or closing of the jaws. In the most intense cases, within from twenty-four to forty-eight hours bloody serum may exude through the skin over the swollen parts, and finally large gangrenous sloughs may form. The temperature is never very high, the pulse is frequent and compressible, and becomes feebler as the animal loses strength. A cough is usually present. The urine is scanty and high colored, and when the intestines are much affected a bloody diarrhea may set in, with colicky pains. Some of the internal organs become implicated in the disease, the lungs may become edematous, extravasation may occur in the intestinal canal, or effusion of serum into the cavity of the chest or abdomen; occasionally the brain becomes affected. A few cases run a mild course and recovery may commence in three or four days; generally, however, the outlook is unfavorable. In severe cases septic poisoning is liable to occur, which soon brings the case to a fatal issue.

Pathology.--On section we find the capillaries dilated, the connective tissue filled with a coagulable or coagulated lymph, and frequently we may discover gangrenous spots beneath the skin or involving the skin. The lymphatic glands are swollen and inflamed. Extensive extravasations of blood may be found embedded between the coats of the intestines, or excessive effusion into the substance of the lungs.

Treatment.--Diffusible stimulants and tonics should be given from the start. Carbonate of ammonia, 1 dram, fluid extract of red cinchona bark, 2 drams, and tincture of ginger half an ounce, with half a pint of water; thin gruel or milk should be given every four or six hours. But especial care should be exercised to avoid injury by drenching. If the horse has difficulty in getting the head up and swallowing, smaller doses must be given with a small hard-rubber syringe. Sulphate of iron in 1-dram doses may be dissolved in water and given every six hours. Chlorate of potassium, in 2-ounce doses, may be given every eight or twelve hours. Colloidal silver may be administered intravenously in doses of from 5 to 12 grains. Washings with lead and alum water are useful and may be repeated several times each day. If the swellings are very great, they may be incised freely and the resulting wounds should be washed at least twice daily with a warm 3 per cent solution of carbolic acid or other good antiseptic. Tracheotomy may be necessary. Complications, when they arise, must be treated with proper circumspection.

DISEASES OF THE LYMPHATIC SYSTEM.

The lymphatic, or absorbent, system is connected with the blood-vascular system, and consists of a series of tubes which absorb and convey to the blood certain fluids. These tubes lead to lymphatic glands, through which the fluids pass to reach the right lymphatic vein and thoracic duct, both of which enter the venous system near the heart. Through the excessively thin walls of the capillaries the fluid part of the blood transudes to nourish the tissues outside the capillaries; at the same time fluid passes from the tissues into the blood. The fluid, after it passes into the tissues, constitutes the lymph, and acts like a stream irrigating the tissue elements. Much of the surplus of this lymph passes into the lymph vessels, which in their commencement can hardly be treated as independent structures, since their walls are so closely joined with the tissues through which they pass, being nothing more than spaces in the connective tissue until they reach the larger lymph vessels, which finally empty into lymph glands. These lymph glands are structures so placed that the lymph flowing toward the larger trunks passes through them, undergoing a sort of filtration. From the fact of this arrangement lymph glands are subject to inflammatory diseases in the vicinity of diseased structures, because infective material being conveyed in the lymph stream lodges in the glands and produces irritation.

LOCAL INFLAMMATION AND ABSCESS OF LYMPHATIC GLANDS.

Acute inflammation of the lymph glands usually occurs in connection with some inflammatory process in the region from which its lymph is gathered. Several or all of the glands in a cluster may become affected, as in strangles, nasal catarrh, or nasal gleet, diseased or ulcerated teeth, the lymph glands between the branches of the lower jaw almost invariably become affected, which may lead to suppuration or induration. Similar results obtain in other portions of the body; in pneumonia the bronchial glands become affected; in pharyngitis the postpharyngeal glands lying above the trachea become affected, etc.

Symptoms.--The glands swell and become painful to the touch, the connective tissue surrounding them becomes involved, suppuration usually takes place, and one or more abscesses form. If the inflammation is of a milder type, resolution may take place and the swelling recede, the exudative material being absorbed, and the gland restored without the occurrence of suppuration. In the limbs a whole chain of the glands along the lymphatic vessels may become affected, as in farcy, phlebitis, or septic poisoning.

Treatment.--Fomentation with hot water and the application of camphorated soap liniment or camphorated oil may produce a revulsive action and prevent suppuration. If there is any indication of abscess forming, poultices of linseed meal and bran made into a paste with hot water should be applied, or a mild blistering ointment rubbed in over the swollen gland. As soon as fluctuation can be felt a free opening must be made for the escape of the contained pus. The wound may subsequently be washed out with a solution of chlorid of zinc, 5 grains to the ounce of water, three times a day.

LYMPHANGITIS.

Specific inflammation of the lymphatic structures usually affects the hind legs; very seldom a fore leg. This disease is very sudden in its attack, exceedingly painful, accompanied by a high temperature and great general disturbance.

Causes.--Horses of lymphatic or sluggish temperament are predisposed to this affection. It usually attacks well-fed animals, and in such cases may be due to an excess of nutritive elements in the blood. Sudden changes in work or in the habits of the animal may induce an attack.

Symptoms.--It is usually ushered in by a chill, rise in temperature, and some uneasiness; in a very short time this is followed by lameness in one leg and swelling on the inside of the thigh. The swelling gradually surrounds the whole limb and continues on downward until it reaches the foot. The limb is excessively tender to the touch, the animal perspires, the breathing is accelerated, pulse hard and quick, and the temperature may reach 106 deg. F. The bowels early become very constipated and urine scanty. The symptoms usually are on the increase for about two days, then they remain stationary for the same length of time; the fever then abates; the swelling recedes and becomes less painful. It is very seldom, though, that all the swelling leaves the leg; generally it leaves some permanent enlargement, and the animal becomes subject to recurrent attacks. Occasionally the inguinal lymphatic glands (in the groin) undergo suppuration, and pyemia may supervene and prove fatal. In severe cases the limb becomes denuded of hair in patches, and the skin remains indurated with a fibrous growth, which is known by the name of elephantiasis.

Treatment.--The parts should be bathed freely and frequently with water as hot as the hand can bear and then fomented with vinegar and water, equal parts, to which add 2 ounces of nitrate of potassium for each gallon. This should be applied frequently, after the hot water, for the first day. Afterwards the leg may be dried with a woolen cloth and bathed with camphorated soap liniment. Internally administer artificial Carlsbad salts in 2 to 4 ounce doses three times daily. Feed lightly and give complete rest. This treatment, if instituted early in the attack, very frequently brings about a remarkable change within 24 hours.

DISEASES OF THE EYE.

BY JAMES LAW, F. R. C. V. S.,

Formerly Professor of Veterinary Science, etc., Cornell University.

We can scarcely overestimate the value of sound eyes in the horse, and hence all diseases and injuries which seriously interfere with vision are matters of extreme gravity and apprehension, for should they prove permanent they invariably depreciate the selling price to a considerable extent. A blind horse is always dangerous in the saddle or in single harness, and he is scarcely less so when, with partially impaired vision, he sees things imperfectly, in a distorted form or in a wrong place, and when he shies or avoids objects which are commonplace or familiar. When we add to this that certain diseases of the eyes, like recurring inflammation (moon blindness), are habitually transmitted from parent to offspring, we can realize still more fully the importance of these maladies. Again, as a mere matter of beauty, a sound, full, clear, intelligent eye is something which must always add a high value to our equine friends and servants.

STRUCTURE OF THE EYE.

(Pl. XXII.)

THE EYEBALL.

A full description of the structure of the eye is incompatible with our prescribed limits, and yet a short description is absolutely essential to the clear understanding of what is to follow.

The horse's eye is a spheroidal body, flattened behind, and with its posterior four-fifths inclosed by an opaque, white, strong fibrous membrane (the sclerotic), on the inner side of which is laid a more delicate, friable membrane, consisting mainly of blood vessels and pigment cells (the choroid), which in its turn is lined by the extremely delicate and sensitive expansion of the nerve of sight (the retina). The anterior fifth of the globe of the eye bulges forward from what would have been the direct line of the sclerotic, and thus forms a segment of a much smaller sphere than is inclosed by the sclerotic. Its walls, too, have in health a perfect translucency, from which it has derived the name of transparent cornea. This transparent coat is composed, in the main, of fibers with lymph interspaces, and it is to the condition of these and their condensation and compression that the translucency is largely due. This may be shown by compressing with the fingers the eye of an ox which has just been killed, when the clear transparent cornea will suddenly become clouded over with a whitish-blue opacity, and this will remain until the compression is interrupted. The interior of the eye contains three transparent media for the refraction of the rays of light on their way from the cornea to the visual nerve. Of these media the anterior one (aqueous humor) is liquid, the posterior (vitreous humor) is semisolid, and the intermediate one (crystalline lens) is solid. The space occupied by the aqueous humor corresponds nearly to the portion of the eye covered by the transparent cornea. It is, however, divided into two chambers, anterior and posterior, by the iris, a contractile curtain with a hole in the center (the pupil), and which may be looked on as in some sense a projection inward of the vascular and pigmentary coat from its anterior margin at the point where the sclerotic or opaque outer coat becomes continuous with the cornea or transparent one. This iris, or curtain, besides its abundance of blood vessels and pigment, possesses two sets of muscular fibers, one set radiating from the margin of the pupil to the outer border of the curtain at its attachment to the sclerotic and choroid, and the other encircling the pupil in the manner of a ring. The action of the two sets is necessarily antagonistic, the radiating fibers dilating the pupil and exposing the interior of the eye to view, while the circular fibers contract this opening and shut out the rays of light. The form of the pupil in the horse is ovoid, with its longest diameter from side to side, and its upper border is fringed by several minute, black bodies (corpora nigra) projecting forward and serving to some extent the purpose of eyebrows in arresting and absorbing the excess of rays of light which fall upon the eye from above. These pigmentary projections in front of the upper border of the pupil are often mistaken for the products of disease or injury in place of the normal and beneficent protectors of the nerve of sight which they are. Like all other parts, they may become the seat of disease, but so long as they and the iris retain their clear, dark, aspect, without any tints of brown or yellow, they may be held to be healthy.

The vitreous or semisolid refracting medium occupies the posterior part of the eye--the part corresponding to the sclerotic, choroid, and retina--and has a consistency corresponding to that of the white of an egg, and a power of refraction of the light rays correspondingly greater than the aqueous humor.

The third or solid refracting medium is a biconvex lens, with its convexity greatest on its posterior surface, which is lodged in a depression in the vitreous humor, while its anterior surface corresponds to the opening of the pupil. It is inclosed in a membranous covering (capsule) and is maintained in position by a membrane (suspensory ligament) which extends from the margin of the lens outward to the sclerotic at the point of junction of the choroid and iris. This ligament is, in its turn, furnished with radiating, muscular fibers, which change the form or position of the lens so as to adapt it to see with equal clearness objects at a distance or close by.

Another point which strikes the observer of the horse's eye is that in the darkness a bright, bluish tinge is reflected from the widely dilated pupil. This is owing to a comparative absence of pigment in the choroid coat inside the upper part of the eyeball, and enables the animal to see and advance with security in darkness where the human eye would be of little use. The lower part of the cavity of the horse's eye, into which the dazzling rays fall from the sky, is furnished with an intensely black lining, by which the rays penetrating the inner nervous layer are instantly absorbed.

MUSCLES OF THE EYE.

These consist of four straight muscles, two oblique, and one retractor. The straight muscles pass from the depth of the orbit forward on the inner, outer, upper, and lower sides of the eyeball, and are fixed to the anterior portion of the fibrous (sclerotic) coat, so that in contracting singly they respectively turn the eye inward, outward, upward, and downward. When all act together they draw the eyeball deeply into its socket. The retractor muscle also consists of four muscular slips, repeating the straight muscles on a smaller scale, but as they are only attached on the back part of the eyeball they are less adapted to roll the eye than to draw it down into its socket. The two oblique muscles rotate the eye on its own axis, the upper one turning its outer surface upward and inward, and the lower one turning it downward and inward.

THE HAW (THE WINKING CARTILAGE, OR CARTILAGO NICTITANS).

This is a structure which, like the retractor muscle, is not found in the eye of man, but it serves in the lower animals to assist in removing foreign bodies from the front of the eyeball. It consists, in the horse, of a cartilage of irregular form, thickened inferiorly and posteriorly where it is intimately connected with the muscles of the eyeball and the fatty material around them, and expanded and flattened anteriorly where its upper surface is concave, and, as it were, molded on the lower and inner surface of the eyeball. Externally it is covered by the mucous membrane which lines the eyelids and extends over the front of the eye. In the ordinary restful state of the eye the edge of this cartilage should just appear as a thin fold of membrane at the inner angle of the eye, but when the eyeball is drawn deeply into the orbit the cartilage is pushed forward, outward, and upward over it until the entire globe may be hidden from sight. This protrusion of the cartilage so as to cover the eye may be induced in the healthy eye by pressing the finger and thumb on the upper and lower lids, so as to cause retraction of the eyeball into the socket. When foreign bodies, such as sand, dust, and chaff, or other irritants, have fallen on the eyeball or eyelids it is similarly projected to push them off, their expulsion being further favored by a profuse flow of tears.

This is seen, to a lesser extent, in all painful inflammations of the eye, and to a very marked degree in lockjaw, when the spasm of the muscles of the eyeball draws the latter deeply into the orbit and projects forward the masses of fat and the cartilage. The brutal practice of cutting off this apparatus whenever it is projected necessitates this explanation, which it is hoped may save to many a faithful servant a most valuable appendage. That the cartilage and membrane may become the seat of disease is undeniable, but so long as its edge is thin and even and its surface smooth and regular the mere fact of its projection over a portion or the whole of the eyeball is no evidence of disease in its substance, nor any warrant for its removal. It is usually but the evidence of the presence of some pain in another part of the eye, which the suffering animal endeavors to assuage by the use of this beneficent provision. For the diseases of the cartilage itself, see "Encephaloid cancer."

LACRIMAL APPARATUS.

This consists, first, of a gland for the secretion of the tears, and, second, of a series of canals for the conveyance of the superfluous tears into the cavity of the nose.

The gland is situated above the outer part of the eyeball, and the tears which have flowed over the eye and reached the inner angle are there directed by a small, conical papilla (lacrimal caruncle) into two minute orifices, and thence by two ducts (lacrimal) to a small pouch (lacrimal sac) from which a canal leads through the bones of the face into the nose. This opens in the lower part of the nose on the floor of the passage and a little outside the line of union of the skin which lines the false nostril with the mucous membrane of the nose. In the ass and mule this opening is situated on the roof instead of the floor of the nose, but still close to the external opening.

EXAMINATION OF THE EYE.

To avoid unnecessary repetition the following general directions are given for the examination of the eye: The eye, and to a certain extent the mucous membrane lining the eyelids, may be exposed to view by gently parting the eyelids with the thumb and forefinger pressed on the middle of the respective lids. The pressure, it is true, causes the protrusion of the haw over a portion of the lower and inner part of the eye, but by gentleness and careful graduation of the pressure this may be kept within bounds, and oftentimes even the interior of the eye can be seen. As a rule it is best to use the right hand for the left eye, and the left hand for the right, the finger in each case being pressed on the upper lid while the thumb depresses the lower one. In cases in which it is desirable to examine the inner side of the eyelid further than is possible by the above means, the upper lid may be drawn down by the eyelashes with the one hand and then everted over the tip of the forefinger of the other hand, or over a probe laid flat against the middle of the lid. When the interior of the eye must be examined it is useless to make the attempt in the open sunshine or under a clear sky. The worst cases, it is true, can be seen under such circumstances, but for the slighter forms the horse should be taken indoors, where all light from above will be shut off, and should be placed so that the light may fall on the eye from the front and side. Then the observer, placing himself in front of the animal, will receive the reflected rays from the cornea, the front of the lens and the back, and can much more easily detect any cloudiness, opacity, or lack of transparency. The examination can be made much more satisfactory by placing the horse in a dark chamber and illuminating the eye by a lamp placed forward and outward from the eye which is to be examined. Any cloudiness is thus easily detected, and any doubt may be resolved by moving the lamp so that the image of the flame may be passed in succession over the whole surface of the transparent cornea and of the crystalline lens. Three images of the flame will be seen, the larger one upright, reflected from the anterior surface of the eye; a smaller one upright, reflected from the anterior surface of the lens; and a second small one inverted from the back surface of the lens.

So long as these images are reflected from healthy surfaces they will be clear and perfect in outline, but as soon as one strikes on an area of opacity it will become diffused, cloudy, and indefinite. Thus, if the large, upright image becomes hazy and imperfect over a particular spot of the cornea, that will be found to be the seat of disease and opacity. Should the large image remain clear, but the small upright one become diffuse and indefinite over a given point, it indicates opacity on the front of the capsule of the lens. If both upright images remain clear while the inverted one becomes indistinct at a given point, then the opacity is in the substance of the lens itself or in the posterior part of its capsule.

If in a given case the pupil remains so closely contracted that the deeper parts of the eye can not be seen, the eyelids may be rubbed with extract of belladonna, and in a short time the pupil will be found widely dilated.

DISEASES OF THE EYELIDS.

CONGENITAL DISORDERS.

Some faulty conditions of the eyelids are congenital, as division of an eyelid in two, after the manner of harelip, abnormally small opening between the lids, often connected with imperfect development of the eye, and closure of the lids by adhesion. The first is to be remedied by paring the edges of the division and then bringing them together, as in torn lids. The last two, if remediable at all, require separation by the knife, and subsequent treatment with a cooling astringent eyewash.

NERVOUS DISORDERS.

SPASM OF EYELIDS may be owing to constitutional susceptibility, or to the presence of local irritants (insects, chemical irritants, sand, etc.) in the eye, to wounds or inflammation of the mucous membrane, or to disease of the brain. When due to local irritation it may be temporarily overcome by instilling a few drops of a 4 per cent solution of cocaine into the eye, when the true cause may be ascertained and removed. The nervous or constitutional disease must be treated according to its nature.

DROOPING EYELIDS, OR PTOSIS.--This is usually present in the upper lid, or is at least little noticed in the lower. It is sometimes but a symptom of paralysis of one-half of the face, in which case the ear, lips, and nostrils on the same side will be found soft, drooping, and inactive, and even the half of the tongue may partake of the palsy. If the same condition exists on both sides, there is difficult, snuffling breathing, from the air drawing in the flaps of the nostrils in inspiration, and all feed is taken in by the teeth, as the lips are useless. In both there is a free discharge of saliva from the mouth during mastication. This paralysis is a frequent result of injury, by a poke, to the seventh nerve, as it passes over the back of the lower jaw. In some cases the paralysis is confined to the lid, the injury having been sustained by the muscles which raise it, or by the supraorbital nerve, which emerges from the bone just above the eye. Such injury to the nerve may have resulted from fracture of the orbital process of the frontal bone above the eyeball.

The condition may, however, be due to spasm of the sphincter muscle, which closes the lids, or to inflammation of the upper lid, usually a result of blows on the orbit. In the latter case it may run a slow course with chronic thickening of the lid.

The paralysis due to the poke may be often remedied, first, by the removal of any remaining inflammation by a wet sponge worn beneath the ear and kept in place by a bandage; secondly, when all inflammation has passed, by a blister on the same region, or by rubbing it daily with a mixture of olive oil and strong aqua ammonia in equal proportions. Improvement is usually slow, and it may be months before complete recovery ensues.

In paralysis from blows above the eyes the same treatment may be applied to that part.

Thickening of the lid may be treated by painting with tincture of iodin, and that failing, by cutting out an elliptical strip of the skin from the middle of the upper lid and stitching the edges together.

INFLAMMATION OF THE EYELIDS.

The eyelids suffer more or less in all severe inflammations of the eye, whether external or internal, but inasmuch as the disease sometimes starts in the lids and at other times is exclusively confined to them, it deserves independent mention.

Among the causes may be named: Exposure to drafts of cold air, or to cold rain or snow storms; the bites or stings of mosquitoes, flies, or other insects; snake bites, pricks with thorns, blows of whip or club; accidental bruises against the stall or ground, especially during the violent struggles of colic, enteritis, phrenitis (staggers), and when thrown for operations. It is also a result of infecting inoculations, as of erysipelas, anthrax, boil, etc., and is noted by Leblanc as especially prevalent among horses kept on low, marshy pastures. Finally, the introduction of sand, dust, chaff, beards of barley and seeds of the finest grasses, and the contact with irritant, chemical powders, liquids, and gases (ammonia from manure or factory, chlorin, strong sulphur fumes, smoke, and other products of combustion, etc.) may start the inflammation. The eyelids often undergo extreme inflammatory and dropsical swelling in urticaria (nettlerash, surfeit) and in the general inflammatory dropsy known as purpura hemorrhagica.

The affection will, therefore, readily divide itself into (1) inflammations due to constitutional causes; (2) those due to direct injury, mechanical or chemical; and (3) such as are due to inoculation with infecting material.

(1) Inflammations due to constitutional causes are distinguished by the absence of any local wound, and the history of a low, damp pasture, exposure, indigestion from unwholesome feed, or the presence elsewhere on the limbs or body of the general, doughy swellings of purpura hemorrhagica. The lids are swollen and thickened; it may be slightly or it may be so extremely that the eyeball can not be seen. If the lid can be everted to show its mucous membrane, that is seen to be of a deep-red color, especially along the branching lines of the blood vessels. The part is hot and painful, and a profuse flow of tears and mucus escapes on the side of the face, causing irritation and loss of the hair. If improvement follows, this discharge becomes more tenacious, and tends to cause adhesion to the edges of the upper and lower lids and to mat together the eyelashes in bundles. This gradually decreases to the natural amount, and the redness and congested appearance of the eye disappears, but swelling, thickening, and stiffness of the lids may continue for a time. There may be more or less fever according to the violence of the inflammation, but so long as there is no serious disease of the interior of the eye or of other vital organ, it is usually moderate.

The local treatment consists in astringent, soothing lotions (sugar of lead 30 grains, laudanum 2 teaspoonfuls, rain water--boiled and cooled--1 pint), applied with a soft cloth kept wet with the lotion, and hung over the eye by tying it to the headstall of the bridle on the two sides. If the mucous membrane lining of the lids is the seat of little red granular elevations, a drop of solution of 2 grains of nitrate of silver in an ounce of distilled water should be applied with the soft end of a clean feather to the inside of the lid twice a day. The patient should be removed from all such conditions (pasture, faulty feed, exposure, etc.) as may have caused or aggravated the disease, and from dust and irritant fumes and gases. He should be fed from a manger high enough to favor the return of blood from the head, and should be kept from work, especially in a tight collar which would prevent the descent of blood by the jugular veins. The diet should be laxative and nonstimulating (grass, bran mashes, carrots, turnips, beets, potatoes, or steamed hay), and any costiveness should be corrected by a mild dose of raw linseed oil (1 to 1-1/2 pints). In cold weather warm blanketing may be needful, and even loose flannel bandages to the limbs, but heat should never be sought at the expense of pure air.

(2) In inflammations due to local irritants of a noninfective kind a careful examination will usually reveal their presence, and the first step must be their removal with a pair of blunt forceps or the point of a lead pencil. Subsequent treatment will be in the main the local treatment advised above.

(3) In case of infective inflammation there will often be found a prick or tear by which the septic matter has entered, and in such case the inflammation will for a time be concentrated at that point. A round or conical swelling around an insect bite is especially characteristic. A snake bite is marked by the double prick made by the two teeth and by the violent and rapidly spreading inflammation. Erysipelas is attended with much swelling, extending beyond the lids and causing the mucous membrane to protrude beyond the edge of the eyelid (chemosis). This is characterized by a bright, uniform, rosy red, disappearing on pressure, or later by a dark, livid hue, but with less branching redness than in noninfecting inflammation and less of the dark, dusky, brownish or yellowish tint of anthrax. Little vesicles may appear on the skin, and pus may be found without any distinct limiting membrane, as in abscess. It is early attended with high fever and marked general weakness and inappetence. Anthrax of the lids is marked by a firm swelling, surmounted by a blister, with bloody serous contents, which tends to burst and dry up into a slough, while the surrounding parts become involved in the same way. Or it may show as a diffuse, dropsical swelling, with less of the hard, central sloughing nodule, but, like that, tending to spread quickly. In both cases alike the mucous membrane and the skin, if white, assumes a dusky-brown or yellowish-brown hue, which is largely characteristic. This may pass into a black color by reason of extravasation of blood. Great constitutional disturbance appears early, with much prostration and weakness and generalized anthrax symptoms.

Treatment.--The treatment will vary according to the severity. Insect bites may be touched with a solution of equal parts of glycerin and aqua ammonia, or a 10 per cent solution of carbolic acid in water. Snake bites may be bathed with aqua ammonia, and the same agent given in doses of 2 teaspoonfuls in a quart of water, or alcohol may be given in pint or quart doses, according to the size of the animal. In erysipelas the skin may be painted with tincture of chlorid of iron, or with a solution of 20 grains of iodin in an ounce of carbolic acid, and one-half an ounce of tincture of chlorid of iron may be given thrice daily in a bottle of water. In anthrax the swelling should be painted with tincture of iodin, or of the mixture of iodin and carbolic acid, and if very threatening it may have the tincture of iodin injected into the swelling with a hypodermic syringe, or the hard mass may be freely incised to its depth with a sharp lancet and the lotion applied to the exposed tissues. Internally, iodid of potassium may be given in doses of 2 drams thrice a day, or tincture of the chlorid of iron every four hours.

STY, OR FURUNCLE (BOIL) OF THE EYELID.

This is an inflammation of limited extent, advancing to the formation of matter and the sloughing out of a small mass of the natural tissue of the eyelid. It forms a firm, rounded swelling, usually near the margin of the lid, which suppurates and bursts in four or five days. Its course may be hastened by a poultice of camomile flowers, to which have been added a few drops of carbolic acid, the whole applied in a very thin muslin bag. If the swelling is slow to open after having become yellowish white, it may be opened by a lancet, the incision being made at right angles to the margin of the lid.

ENTROPION AND ECTROPION, OR INVERSION AND EVERSION OF THE EYELID.

These are respectively caused by wounds, sloughs, ulcers, or other causes of loss of substance of the mucous membrane on the inside of the lid and of the skin on the outside; also of tumors, skin diseases, or paralysis which leads to displacement of the margin of the eyelid. As a rule, they require a surgical operation, with removal of an elliptical portion of the mucous membrane or skin, as the case may be, but which requires the skilled and delicate hand of the surgeon.

TRICHIASIS.

This consists in the turning in of the eyelashes so as to irritate the front of the eye. If a single eyelash, it may be snipped off with scissors close to the margin of the eyelid or pulled out by the root with a pair of flat-bladed forceps. If the divergent lashes are more numerous, the treatment may be as for entropion, by excising an elliptical portion of skin opposite the offending lashes and stitching the edges together, so as to draw outward the margin of the lid at that point.

WARTS AND OTHER TUMORS OF THE EYELIDS.

The eyelids form a favorite site for tumors, and above all, warts, which consist in a simple diseased overgrowth (hypertrophy) of the surface layers of the skin. If small, they may be snipped off with scissors or tied around the neck with a stout, waxed thread and left to drop off, the destruction being completed, if necessary, by the daily application of a piece of sulphate of copper (blue vitriol), until any unhealthy material has been removed. If more widely spread, the wart may still be clipped off with curved scissors or knife, and the caustic thoroughly applied day by day.

A bleeding wart, or erectile tumor, is more liable to bleed, and is best removed by constricting its neck with the waxed cord or rubber band, or if too broad it may be transfixed through its base by a needle armed with a double thread, which is then to be cut in two and tied around the two portions of the neck of the tumor. If still broader, the armed needle may be carried through the base of the tumor at regular intervals, so that the whole may be tied in moderately sized sections.

In gray and in white horses black, pigmentary tumors (melanotic) are common on the black portions of skin, such as the eyelids, and are to be removed by scissors or knife, according to their size. In the horse they do not usually tend to recur when thoroughly removed, but at times they prove cancerous (as is the rule in man), and then they tend to reappear in the same site or in internal organs with, it may be, fatal effect.

Encysted, honeylike (melicerous), sebaceous, and fibrous tumors of the lids all require removal with the knife.

TORN EYELIDS OR WOUNDS OF EYELIDS.

The eyelids are torn by attacks with horns of cattle, or with the teeth, or by getting caught on nails in stall, rack, or manger, on the point of stumps, fences, or fence rails, on the barbs of wire fences, and on other pointed bodies. The edges should be brought together as promptly as possible, so as to effect union without the formation of matter, puckering of the skin, and unsightly distortions. Great care is necessary to bring the two edges together evenly without twisting or puckering. The simplest mode of holding them together is by a series of sharp pins passed through the lips of the wound at intervals of not more than a third of an inch, and held together by a thread twisted around each pin in the form of the figure 8, and carried obliquely from pin to pin in two directions, so as to prevent gaping of the wound in the intervals. The points of the pins may then be cut off with scissors, and the wound may be wet twice a day with a weak solution of carbolic acid.

TUMOR OF THE HAW, OR CARIES OF THE CARTILAGE.

Though cruelly excised for alleged "hooks," when itself perfectly healthy, in the various diseases which lead to retraction of the eye into its socket, the haw may, like other bodily structures, be itself the seat of actual disease. The pigmentary, black tumors of white horses and soft (encephaloid) cancer may attack this part primarily or extend to it from the eyeball or eyelids; hairs have been found growing from its surface, and the mucous membrane covering it becomes inflamed in common with that covering the front of the eye. These inflammations are but a phase of the inflammation of the external structures of the eye, and demand no particular notice nor special treatment. The tumors lead to such irregular enlargement and distortion of the haw that the condition is not to be confounded with the simple projection of the healthy structure over the eye when the lids are pushed apart with the finger and thumb, and the same remark applies to the ulceration, or caries, of the cartilage. In the latter case, besides the swelling and distortion of the haw, there is this peculiarity, that in the midst of the red inflamed mass there appears a white line or mass formed by the exposed edge of the ulcerating cartilage. The animal having been thrown and properly fixed, an assistant holds the eyelids apart while the operator seizes the haw with forceps or hook and carefully dissects it out with blunt-pointed scissors. The eye is then covered with a cloth, kept wet with an eyewash, as for external ophthalmia.

OBSTRUCTION OF THE LACRIMAL APPARATUS, OR WATERING EYE.

The escape of tears on the side of the cheek is a symptom of external inflammation of the eye, but it may also occur from any disease of the lacrimal apparatus which interferes with the normal progress of the tears to the nose; hence, in all cases when this symptom is not attended with special redness or swelling of the eyelids, it is well to examine the lacrimal apparatus. In some instances the orifice of the lacrimal duct on the floor of the nasal chamber and close to its anterior outlet will be found blocked by a portion of dry mucopurulent matter, on the removal of which tears may begin to escape. This implies an inflammation of the canal, which may be helped by occasional sponging out of the nose with warm water, and the application of the same on the face. Another remedy is to feed warm mashes of wheat bran from a nosebag, so that the relaxing effects of the water vapor may be secured.

The two lacrimal openings, situated at the inner angle of the eye, may fail to admit the tears by reason of their deviation outward in connection with the eversion of the lower lid or by reason of their constriction in inflammation of the mucous membrane. The lacrimal sac, into which the lacrimal ducts open, may fail to discharge its contents by reason of constriction or closure of the duct leading to the nose, and it then forms a rounded swelling beneath the inner angle of the eye. The duct leading from the sac to the nose may be compressed or obliterated by fractures of the bones of the face, and in disease of these bones (osteosarcoma, so-called osteoporosis, diseased teeth, glanders of the nasal sinuses, abscess of the same cavities).

The narrowed or obstructed ducts may be made pervious by a fine, silver probe passed down to the lacrimal sac, and any existing inflammation of the passages may be counteracted by the use of steaming mashes of wheat bran, by fomentations or wet cloths over the face, and even by the use of astringent eyewashes and the injection of similar liquids into the lacrimal canal from its nasal opening. The ordinary eyewash may be used for this purpose, or it may be injected after dilution to half its strength. The fractures and diseases of the bones and teeth must be treated according to their special demands when, if the canal is still left pervious, it may be again rendered useful.

EXTERNAL OPHTHALMIA, OR CONJUNCTIVITIS.

In inflammation of the outer parts of the eyeball the exposed vascular and sensitive mucous membrane (conjunctiva) which covers the ball, the eyelids, the haw, and the lacrimal apparatus, is usually the most deeply involved, yet adjacent parts are more or less implicated, and when disease is concentrated on these contiguous parts it constitutes a phase of external opththalmia which demands a special notice. These have accordingly been already treated of.

Causes.--The causes of external opththalmia are mainly those that act locally--blows with whips, clubs, and twigs, the presence of foreign bodies, like hayseed, chaff, dust, lime, sand, snuff, pollen of plants, flies attracted by the brilliancy of the eye, wounds of the bridle, the migration of the scabies (mange) insect into the eye, smoke, ammonia arising from the excretions, irritant emanations from drying marshes, etc. Road dust containing infecting microbes is a common factor. A very dry air is alleged to act injuriously by drying the eye as well as by favoring the production of irritant dust; the undue exposure to bright sunshine through a window in front of the stall, or to the reflection from snow or water, also is undoubtedly injurious. The unprotected exposure of the eyes to sunshine through the use of a very short overdraw check is to be condemned, and the keeping of the horse in a very dark stall, from which it is habitually led into the glare of full sunlight, intensified by reflection from snow or white limestone, must be set down among the locally acting causes. Exposure to cold and wet, to wet and snow storms, to cold drafts and wet lairs must also be accepted as causes of conjunctivitis, the general disorder which they produce affecting the eye, if that happens to be the weakest and most susceptible organ of the body, or if it has been subjected to any special local injury, like dust, irritant gases, or excess of light. Again, external opththalmia is a constant concomitant of inflammation of the contiguous and continuous mucous membranes, as those of the nose and throat--hence the red, watery eyes that attend on nasal catarrh, sore throat, influenza, strangles, nasal glanders, and the like. In such cases, however, the affection of the eye is subsidiary and is manifestly overshadowed by the primary and predominating disease.

Symptoms.--The symptoms are watering of the eye, swollen lids, redness of the mucous membrane exposed by the separation of the lids--it may be a mere pink blush with more or less branching redness, or it may be a deep, dark red, as from effusion of blood--and a bluish opacity of the cornea, which is normally clear and translucent. Except when resulting from wounds and actual extravasation of blood, however, the redness is seen to be superficial, and if the opacity is confined to the edges, and does not involve the entire cornea, the aqueous humor behind is seen to be still clear and limpid. The fever is always less severe than in internal ophthalmia, and runs high only in the worst cases. The eyelids may be kept closed, the eyeball retracted, and the haw protruded over one-third or one-half of the ball, but this is due to the pain only and not to any excessive sensibility to light, as shown by the comparatively widely dilated pupil. In internal ophthalmia, on the contrary, the narrow, contracted pupil is the measure of the pain caused by the falling of light on the inflamed and sensitive optic nerve (retina) and choroid.

If the affection has resulted from a wound of the cornea, not only is that the point of greatest opacity, forming a white speck or fleecy cloud, but too often blood vessels begin to extend from the adjacent vascular covering of the eye (sclerotic) to the white spot, and that portion of the cornea is rendered permanently opaque. Again, if the wound has been severe, though still short of cutting into the anterior layers of the cornea, the injury may lead to ulceration that may penetrate more or less deeply and leave a breach in the tissue which, if filled up at all, is repaired by opaque fibrous tissue in place of the transparent cellular structure. Pus may form, and the cornea assumes a yellowish tinge and bursts, giving rise to a deep sore which is liable to extend as an ulcer, and may be in its turn followed by bulging of the cornea at that point (staphyloma). This inflammation of the conjunctiva may be simply catarrhal, with profuse mucopurulent discharge; it may be granular, the surface being covered with minute reddish elevations, or it may become the seat of a false membrane (diphtheria).

Treatment.--In treating external ophthalmia the first object is the removal of the cause. Remove any dust, chaff, thorn, or other foreign body from the conjunctiva, purify the stable from all sources of ammoniacal or other irritant gas; keep the horse from dusty roads, and, above all, from the proximity of a leading wagon and its attendant cloud of dust; remove from pasture and feed from a rack which is neither so high as to drop seeds, etc., into the eyes nor so low as to favor the accumulation of blood in the head; avoid equally excess of light from a sunny window in front of the stall and excess of darkness from the absence of windows; preserve from cold drafts and rains and wet bedding, and apply curative measures for inflammation of the adjacent mucous membranes or skin. If the irritant has been of a caustic nature, remove any remnant of it by persistent bathing with tepid water and a soft sponge, or with water mixed with white of egg, or a glass filled with the liquid may be inverted over the eye so that its contents may dilute and remove the irritant. If the suffering is very severe, a lotion with a few grains of extract of belladonna or of morphia in an ounce of water may be applied, or, if it is available, a few drops of 4 per cent solution of cocaine may be instilled into the eye.

In strong, vigorous patients benefit will usually be obtained from a laxative, such as 2 tablespoonfuls of Glauber's salt daily, and if the fever runs high from a daily dose of half an ounce of saltpeter. As local applications, astringent solutions are usually the best, as 30 grains of borax or of sulphate of zinc in a quart of water, to be applied constantly on a cloth, as advised under "Inflammation of the eyelids." In the absence of anything better, cold water may serve every purpose. Above all, adhesive and oily agents (molasses, sugar, fats) are to be avoided, as only adding to the irritation. By way of suggesting agents that may be used with good effect, salt and sulphate of soda may be named, in solutions double the strength of sulphate of zinc, or 7 grains of nitrate of silver may be added to a quart of distilled water, and will be found especially applicable in granular conjunctivitis, diphtheria, or commencing ulceration. A cantharides blister (1 part of Spanish fly to 4 parts lard) may be rubbed on the side of the face 3 inches below the eye, and washed off next morning with soapsuds and oiled daily till the scabs are dropped.

WHITE SPECKS AND CLOUDINESS OF THE CORNEA.

As a result of external ophthalmia, opaque specks, clouds, or haziness are too often left on the cornea and require for their removal that they be daily touched with a soft feather dipped in a solution of 3 grains nitrate of silver in 1 ounce distilled water. This should be applied until all inflammation has subsided, and until its contact is comparatively painless. It is rarely successful with an old, thick scar following an ulcer, nor with an opacity having red blood vessels running across it.

ULCERS OF THE CORNEA.

These may be treated with nitrate of silver lotion of twice the strength used for opacities. Powdered gentian, one-half ounce, and sulphate of iron, one-fourth ounce, daily, may improve the general health and increase the reparatory power.

INTERNAL OPHTHALMIA (IRITIS, CHOROIDITIS, AND RETINITIS).

Although inflammations of the iris, choroid, and retina--the inner, vascular, and nervous coats of the eye--occur to a certain extent independently of each other, yet one usually supervenes upon the other, and, as the symptoms are thus made to coincide, it will be best for our present purposes to treat the three as one disease.

Causes.--The causes of internal ophthalmia are largely those of the external form only, acting with greater intensity or on a more susceptible eye. Severe blows, bruises, punctures, etc., of the eye, the penetration of foreign bodies into the eye (thorns, splinters of iron, etc.), sudden transition from a dark stall to bright sunshine, to the glare of snow or water, constant glare from a sunny window, abuse of the overdraw checkrein, vivid lightning flashes, drafts of cold, damp air; above all, when the animal is perspiring, exposure in cold rain or snowstorms, swimming cold rivers; also certain general diseases like rheumatism, arthritis, influenza, and disorders of the digestive organs, may become complicated by this affection. From the close relation between the brain and eye--alike in the blood vessels and nerves--disorders of the first lead to affection of the second, and the same remark applies to the persistent irritation to which the jaws are subjected in the course of dentition. So potent is the last agency that we dread a recurrence of ophthalmia so long as dentition is incomplete, and hope for immunity if the animal completes its dentition without any permanent structural change in the eye.

Symptoms.--The symptoms will vary according to the cause. If the attack is due to direct physical injury, the inflammation of the eyelids and superficial structures may be quite as marked as that of the interior of the eye. If, on the other hand, from general causes, or as a complication of some distant disease, the affection may be largely confined to the deeper structures, and the swelling, redness, and tenderness of the superficial structures will be less marked. When the external coats thus comparatively escape, the extreme anterior edge of the white or sclerotic coat, where it overlaps the border of the transparent cornea, is in a measure free from congestion, and, in the absence of the obscuring dark pigment, forms a whitish ring around the cornea. This is partly due to the fact that a series of arteries (ciliary) passing to the inflamed iris penetrate the sclerotic coat a short distance behind its anterior border, and there is therefore a marked difference in color between the general sclerotic occupied between these congested vessels and the anterior rim from which they are absent. Unfortunately, the pigment is often so abundant in the anterior part of the sclerotic as to hide this symptom. In internal ophthalmia the opacity of the cornea may be confined to a zone around the outer margin of the cornea, and even this may be a bluish haze rather than a deep, fleecy white. In consequence it becomes impossible to see the interior of the chamber for the aqueous humor and the condition of the iris and pupil. The aqueous humor is usually turbid, and has numerous yellowish-white flakes floating on its substance or deposited in the lower part of the chamber, so as to cut off the view of the lower portion of the iris. The still visible portion of the iris has lost its natural, clear, dark luster, which is replaced by a brownish or yellowish sere-leaf color. This is more marked in proportion as the iris is inflamed, and less so as the inflammation is confined to the choroid. The quantity of flocculent deposit in the chamber of the aqueous humor is also in direct ratio to the inflammation of the iris. Perhaps the most marked feature of internal ophthalmia is the extreme and painful sensitiveness to light. On this account the lids are usually closed, but when opened the pupil is seen to be narrowly closed, even if the animal has been kept in a darkened stall. Exceptions to this are seen when inflammatory effusion has overfilled the globe of the eye, and by pressure on the retina has paralyzed it, or when the exudation into the substance of the retina itself has similarly led to its paralysis. Then the pupil may be dilated, and frequently its margin loses its regular, ovoid outline and becomes uneven by reason of the adhesions which it has contracted with the capsule of the lens, through its inflammatory exudations. In the case of excessive effusion into the globe of the eye that is found to have become tense and hard so that it can not be indented with the tip of the finger, paralysis of the retina is liable to result. With such paralysis of the retina, vision is heavily clouded or entirely lost; hence, in spite of the open pupil, the finger may be approached to the eye without the animal's becoming conscious of it until it touches the surface, and if the nose on the affected side is gently struck and a feint made to repeat the blow the patient makes no effort to evade it. Sometimes the edges of the contracted pupil become adherent to each other by an intervening plastic exudation, and the opening becomes virtually abolished. In severe inflammations pus may form in the choroid or iris, and escaping into the cavity of the aqueous humor show as a yellowish-white stratum below. In nearly all cases there is resulting exudation into the lens or its capsule, constituting a cloudiness or opacity (cataract), which in severe and old-standing cases appears as a white, fleecy mass behind a widely dilated pupil. In the slighter cases cataract is to be recognized by examination of the eye in a dark chamber, with an oblique side light, as described in the introduction to this article. Cataracts that appear as a simple haze or indefinite, fleecy cloud are usually on the capsule (capsular), while those that show a radiating arrangement are in the lens (lenticular), the radiating fibers of which the exudate follows. Black cataracts are formed by the adhesion of the pigment on the back of the iris to the front of the lens, and by the subsequent tearing loose of the iris, leaving a portion of its pigment adherent to the capsule of the lens. If the pupil is so contracted that it is impossible to see the lens, it may be dilated by applying to the front of the eye with a feather some drops of a solution of 4 grains of atropia in an ounce of water.

Treatment.--The treatment of internal ophthalmia should embrace, first, the removal of all existing causes or sources of aggravation of the disease, which need not be repeated here. Special care to protect the patient against strong light, cold, wet weather, and active exertion must, however, be insisted on. A dark stall and a cloth hung over the eye are important, while cleanliness, warmth, dryness, and rest are equally demanded. If the patient is strong and vigorous, a dose of 4 drams of Barbados aloes may be given, and if there is any reason to suspect a rheumatic origin one-half a dram powdered colchicum and one-half ounce salicylate of soda may be given daily. Locally the astringent lotions advised for external ophthalmia may be resorted to, especially when the superficial inflammation is well marked. More important, however, is to instill into the eye, a few drops at a time, a solution of 4 grains of atropia in 1 ounce of distilled water. This may be effected with the aid of a soft feather, and may be repeated at intervals of 10 minutes until the pupil is widely dilated. As the horse is to be kept in a dark stall, the consequent admission of light will be harmless, and the dilation of the pupil prevents adhesion between the iris and lens, relieves the constant tension of the eye in the effort to adapt the pupil to the light, and solicits the contraction of the blood vessels of the eye and the lessening of congestion, exudation, and intraocular pressure. Should atropia not agree with the case, it may be replaced by morphia (same strength) or cocaine in 4 per cent solution. Another local measure is a blister, which can usually be applied to advantage on the side of the nose or beneath the ear. Spanish flies may be used as for external ophthalmia. In very severe cases the parts beneath the eye may be shaved and three or four leeches applied. Setons are sometimes beneficial, and even puncture of the eyeball, but these should be reserved for professional hands.

The diet throughout should be easily digestible and moderate in quantity--bran mash, middlings, grass, steamed hay, etc.

Even after the active inflammation has subsided the atropia lotion should be continued for several weeks to keep the eye in a state of rest in its still weak and irritable condition, and during this period the patient should be kept in semidarkness, or taken out only with a dark shade over the eye. For the same reason heavy drafts and, rapid paces, which would cause congestion of the head, should be carefully avoided.

RECURRENT OPHTHALMIA (PERIODIC OPHTHALMIA, OR MOON-BLINDNESS).

This is an inflammatory affection of the interior of the eye, intimately related to certain soils, climates, and systems, showing a strong tendency to recur again and again, and usually ending in blindness from cataract or other serious injury.

Causes.--Its causes may be fundamentally attributed to soil. On damp clays and marshy grounds, on the frequently overflowed river bottoms and deltas, on the coasts of seas and lakes alternately submerged and exposed, this disease prevails extensively, and in many instances in France (Reynal), Belgium, Alsace (Zundel, Miltenberger), Germany, and England it has very largely decreased under land drainage and improved methods of culture. Other influences, more or less associated with such soil, are potent causative factors. Thus damp air and a cloudy, wet climate, so constantly associated with wet lands, are universally charged with causing the disease. These act on the animal body to produce a lymphatic constitution with an excess of connective tissue, bones, and muscles of coarse, open texture, thick skins, and gummy legs covered with a profusion of long hair. Hence the heavy horses of Belgium and southwestern France have suffered severely from the affection, while high, dry lands adjacent, like Catalonia, in Spain, and Dauphiny, Provence, and Languedoc; in France, have in the main escaped.

The rank, aqueous fodders grown on such soils are other causes, but these again are calculated to undermine the character of the nervous and sanguineous temperament and to superinduce the lymphatic. Other feeds act by leading to constipation and other disorders of the digestive organs, thus impairing the general health. Hence in any animal predisposed to this disease, heating, starchy feeds, such as maize, wheat, and buckwheat, are to be carefully avoided. It has been widely charged that beans, peas, vetches, and other Leguminosae are dangerous, but a fuller inquiry contradicts the statement. If these feeds are well grown, they invigorate and fortify the system, while, like any other fodder, if grown rank; aqueous, and deficient in assimilable principles, they tend to lower the health and open the way for the disease.

The period of dentition and training is a fertile exciting cause, for though the malady may appear at any time from birth to old age, yet the great majority of victims are from 2 to 6 years old, and if a horse escapes the affection till after 6 there is a reasonable hope that he will continue to resist it. The irritation about the head during the eruption of the teeth, and while fretting in the unwonted bridle and collar, the stimulating grain diet and the close air of the stable all combine to rouse the latent tendency to disease in the eye, while direct injuries by bridle, whip, or hay seeds are not without their influence. In the same way local irritants, like dust, severe rain and snow storms, smoke, and acrid vapors are contributing causes.

It is evident, however, that no one of these is sufficient of itself to produce the disease, and it has been alleged that the true cause is a microbe, or the irritant products of a microbe, which is harbored in the marshy soil. The prevalence of the disease on the same damp soils which produce ague in man and anthrax in cattle has been quoted in support of this doctrine, as also the fact that, other things being equal, the malady is always more prevalent in basins surrounded by hills where the air is still and such products are concentrated, and that a forest or simple belt of trees will, as in ague, at times limit the area of its prevalence. Another argument for the same view is found in the fact that on certain farms irrigated by town sewage this malady has become extremely prevalent, the sewage being assumed to form a suitable nidus for the growth of the germ. But on these sewage farms a fresh crop may be cut every fortnight, and the product is precisely that aqueous material which contributes to a lymphatic structure and a low tone of health. The presence of a definite germ in the system has not yet been proved, and in the present state of our knowledge we are only warranted in charging the disease to the deleterious emanations from the marshy soil in which bacterial ferments are constantly producing them.

Heredity is one of the most potent causes. The lymphatic constitution is of course transmitted and with it the proclivity to recurring ophthalmia. This is notorious in the case of both parents, male and female. The tendency appears to be stronger, however, if either parent has already suffered. Thus a mare may have borne a number of sound foals, and then fallen a victim to the malady, and all foals subsequently borne have likewise suffered. So it is in the case of the stallion. Reynal even quotes the appearance of the disease in alternate generations, the stallion offspring of blind parents remaining sound through life and yet producing foals which furnish numerous victims of recurrent ophthalmia. On the contrary, the offspring of diseased parents removed to high, dry regions and furnished with wholesome, nourishing rations will nearly all escape. Hence the dealers take colts that are still sound or have had but one attack from the affected low Pyrenees (France) to the unaffected Catalonia (Spain), with confidence that they will escape, and from the Jura Valley to Dauphiny with the same result.

Yet the hereditary taint is so strong and pernicious that intelligent horsemen everywhere refuse to breed from either horse or mare that has once suffered from recurrent ophthalmia, and the French Government studs not only reject all unsound stallions, but refuse service to any mare which has suffered with her eyes. It is this avoidance of the hereditary predisposition more than anything else that has reduced the formerly wide prevalence of this disease in the European countries generally. A consideration for the future of our horses would demand the disuse of all sires that are unlicensed, and the refusal of a license to any sire which has suffered from this or any other communicable constitutional disease.

Other contributing causes deserve passing mention. Unwholesome feed and a faulty method of feeding undoubtedly predisposes to the disease, and in the same district the carefully fed will escape in far larger proportion than the badly fed; it is so also with every other condition which undermines the general health. The presence of worms in the intestines, overwork, and debilitating diseases and causes of every kind weaken the vitality and lay the system more open to attack. Thierry long ago showed that the improvement of close, low, dark, damp stables, where the disease had previously prevailed, practically banished the affection. Whatever contributes to strength and vigor is protective; whatever contributes to weakness and poor health is provocative of the disease in the predisposed subject.

Symptoms.--The symptoms vary according to the severity of the attack. In some cases there is marked fever, and in some slighter cases it may be almost altogether wanting, but there is always a lack of vigor and energy, bespeaking general disorder. The local symptoms are in the main those of internal ophthalmia, in many cases with an increased hardness of the eyeball from effusion into its cavity. The contracted pupil does not expand much in darkness, nor even under the action of belladonna. Opacity advances from the margin, over a part or whole of the cornea, but so long as it is transparent there may be seen the turbid, aqueous humor with or without flocculi, the dingy iris robbed of its clear, black aspect, the slightly clouded lens, and a greenish-yellow reflection from the depth of the eye. From the fifth to the seventh day the flocculi precipitate in the lower part of the chamber, exposing more clearly the iris and lens, and absorption commences, so that the eye may be cleared up in ten or fifteen days.

The characteristic of the disease is, however, its recurrence again and again in the same eye until blindness results. The attacks may follow one another after intervals of a month, more or less, but they show no relation to any particular phase of the moon, as might be inferred from the familiar name, but are determined rather by the weather, the health, the feed, or by some periodicity of the system. From five to seven attacks usually result in blindness, and then the second eye is liable to be attacked until it also is ruined.

In the intervals between the attacks some remaining symptoms betray the condition, and they become more marked after each successive access of disease. Even after the first attack there is a bluish ring around the margin of the transparent cornea. The eye seems smaller than the other, at first because it is retracted in its socket, and often after several attacks because of actual shrinkage (atrophy). The upper eyelid, in place of presenting a uniform, continuous arch, has, about one-third from its inner angle, an abrupt bend, caused by the contraction of the levator muscle. The front of the iris has exchanged some of its dark, clear brilliancy for a lusterless yellow, and the depth of the eye presents more or less of the greenish-yellow shade. The pupil remains a little contracted, except in advanced and aggravated cases, when, with opaque lens, it is widely dilated. If, as is common, one eye only has suffered, the contrast in these respects with the sound eye is all the more characteristic. Another feature is the erect, attentive carriage of the ear, to compensate to some extent for the waning vision.

The attacks vary greatly in severity in different cases, but the recurrence is characteristic, and all alike lead to cataract and intraocular effusion, with pressure on the retina and abolition of sight.

Prevention.--The prevention of this disease is the great object to be aimed at, and this demands the most careful breeding, feeding, housing, and general management, as indicated under "Causes." Much can also be done by migration to a high, dry location, but for this and malarious affections the improvement of the land by drainage and good cultivation should be the final aim.

Treatment is not satisfactory, but is largely the same as for common internal ophthalmia. Some cases, like rheumatism, are benefited by 1-scruple doses of powdered colchicum and 2-dram doses of salicylate of soda twice a day. In other cases, with marked hardness of the globe of the eye from intraocular effusion, aseptic puncture of the eye, or even the excision of a portion of the iris, has helped. During recovery a course of tonics (2 drams oxid of iron, 10 grains nux vomica, and 1 ounce sulphate of soda daily) is desirable to invigorate the system and help to ward off another attack. The vulgar resort to knocking out the wolf teeth and cutting out the haw can only be condemned. The temporary recovery would take place in one or two weeks, though no such thing had been done, and the breaking of a small tooth, leaving its fang in the jaw, only increases the irritation.

CATARACT.

The common result of internal ophthalmia, as of the recurrent type, may be recognized as described under the first of these diseases. Its offensive appearance may be obviated by extraction or depression of the lens, but as the rays of light would no longer be properly refracted, perfect vision would not be restored, and the animal would be liable to prove an inveterate shyer. If perfect blindness continued by reason of pressure on the nerve of sight, no shying would result.

PALSY OF THE NERVE OF SIGHT, OR AMAUROSIS.

Causes.--The causes of this affection are tumors or other disease of the brain implicating the roots of the optic nerve, injury to the nerve between the brain and eye, and inflammation of the optic nerve within the eye (retina), or undue pressure on the same from dropsical or inflammatory effusion. It may also occur from overloaded stomach, from a profuse bleeding, and even from the pressure of the gravid womb in gestation.

Symptoms.--The symptoms are wide dilatation of the pupils, so as to expose fully the interior of the globe, the expansion remaining the same in light and darkness. Ordinary eyes when brought to the light have the pupils suddenly contract and then dilate and contract alternately until they adapt themselves to the light. The horse does not swerve when a feint to strike is made unless the hand causes a current of air. The ears are held erect, turn quickly toward any noise, and the horse steps high to avoid stumbling over objects which it can not see.

Treatment is only useful when the disease is symptomatic of some removable cause, like congested brain, overloaded stomach, or gravid womb. When recovery does not follow the termination of these conditions, apply a blister behind the ear and give one-half dram doses of nux vomica daily.

TUMORS OF THE EYEBALL.

A variety of tumors attack the eyeball--dermoid, papillary, fatty, cystic, and melanotic--but perhaps the most frequent in the horse is encephaloid cancer. This may grow in or on the globe, the haw, the eyelid, or the bones of the orbit, and can be remedied, if at all, only by early and thorough excision. It may be distinguished from the less dangerous tumors by its softness, friability, and great vascularity, bleeding on the slightest touch, as well as by its anatomical structure.

STAPHYLOMA.

This consists in a bulging forward of the cornea at a given point by the sacculate yielding and distention of its coats, and it may be either transparent or opaque and vascular. In the last form the iris has become adherent to the back of the cornea, and the whole structure is filled with blood vessels. In the first form the bulging cornea is attenuated; in the last it may be thickened. The best treatment is by excision of a portion of the rise so as to relieve the intraocular pressure.

PARASITES IN THE EYE.

Acari in the eye have been incidentally alluded to under inflammation of the lids.

Filaria palpebralis is a white worm, one-half to 1 inch long, which inhabits the lacrimal duct and the underside of the eyelids and haw in the horse, producing a verminous conjunctivitis. The first step in treatment in such cases is to remove the worm with forceps, then treat as for external inflammation.

Setaria equina is a delicate, white, silvery-looking worm, which I have repeatedly found 2 inches in length (a length as great as 5 inches has been reported). It invades the aqueous humor, where its constant active movements make it an object of great interest, and it is frequently exhibited as a "snake in the eye."[1] When present in the eye it causes inflammation and has to be removed through an incision made with the lancet in the upper border of the cornea close to the sclerotic, the point of the instrument being directed slightly forward to avoid injury to the iris. Then cold water or astringent antiseptic lotions should be applied.

Filaria conjunctivae, resembling Setaria equina very much in size and general appearance, is another roundworm which has been found in the eye of the horse.

The echinococcus, the cystic or larval stage of the echinococcus tapeworm of the dog, has been found in the eye of the horse, and a cysticercus is also reported.

FOOTNOTES:

[1] This worm is normally a parasite of the peritoneal cavity, and is probably transmitted from one horse to another by some biting insect which becomes infected by embryos in the blood.--M. C. HALL.

LAMENESS: ITS CAUSES AND TREATMENT.

BY A. LIAUTARD, M. D., V. M.,

Formerly principal of the American Veterinary College, New York.

[Revised by John R. Mohler, A. M., V. M. D.]

It is as living, organized, locomotive machines that the horse, camel, ox, and their burden-bearing companions are of practical value to man. Hence the consideration of their usefulness and consequent value to their human masters ultimately and naturally resolves itself into an inquiry concerning the condition of that special portion of their organism which controls their function of locomotion. This is especially true in regard to the members of the equine family, the most numerous and valuable of all the beasts of burden, and it naturally follows that with the horse for a subject of discussion the special topic and leading theme of inquiry, by an easy lapse, will become an inquest into the condition and efficiency of his power for usefulness as a carrier or traveler. There is a great deal of abstract interest in the study of that endowment of the animal economy which enables its possessor to change his place at will and convey himself whithersoever his needs or his moods may incline him; how much greater, however, the interest that attaches to the subject when it becomes a practical and economic question and includes within its purview the various related topics which belong to the domains of physiology, pathology, therapeutics, and the entire round of scientific investigation into which it is finally merged as a subject for medical and surgical consideration--in a word, of actual disease and its treatment. It is not surprising that the intricate and complicated apparatus of locomotion, with its symmetry and harmony of movement and the perfection and beauty of its details and adjuncts, by students of creative design and attentive observers or nature and her marvelous contrivances and adaptations, should be admiringly denominated a living machine.

Of all the animal tribe the horse, in a state of domesticity, is the largest sharer with his master in his liability to the accidents and dangers which are among the incidents of civilized life. From his exposure to the missiles of war on the battlefield to his chance of picking up a nail from the city pavement there is no hour when he is not in danger of incurring injuries which for their repair may demand the best skill of the veterinary practitioner. This is true not alone of casualties which belong to the class of external and traumatic cases, but includes as well those of a kind perhaps more numerous, which may result in lesions of internal parts, frequently the most serious and obscure of all in their nature and effects.

The horse is too important a factor in the practical details of human life and fills too large a place in the business and pleasure of the world to justify any indifference to his needs and physical comfort or neglect in respect to the preservation of his peculiar powers for usefulness. In entering somewhat largely, therefore, upon a review of the subject, and treating in detail of the causes, the symptoms, the progress, the treatment, the results, and the consequences of lameness in the horse, we are performing a duty which needs no word of apology or justification. The subject explains and justifies itself, and is its own vindication and illustration, if any are needed.

The function of locomotion is performed by the action of two principal systems of organs, known in anatomical and physiological terminology as passive and active, the muscles performing the active and the bones the passive portion of the movement. The necessary connection between the cooperating parts of the organism is effected by means of a vital contact by which the muscle is attached to the bone at certain determinate points on the surface of the latter. These points of attachment appear sometimes as an eminence, sometimes as a depression, sometimes a border or an angle, or again as a mere roughness, but each perfectly fulfilling its purpose, while the necessary motion is provided for by the formation of the ends of the long bones into the requisite articulations, joints, or hinges. Every motion is the product of the contraction of one or more of the muscles, which, as it acts upon the bony levers, gives rise to a movement of extension or flexion, abduction or adduction, rotation or circumduction. The movement of abduction is that which passes from and that of adduction that which passes toward the median line, or the center of the body. The movements of flexion and extension are too well understood to need defining. It is the combination and rapid alterations of these movements which produce the different postures and various gaits of the animal, and it is their interruption and derangement, from whatever causes, which constitute the pathological condition known as lameness.

A concise examination of the general anatomy of these organs, however, must precede the consideration of the pathological questions pertaining to the subject. A statement, such as we have just given, containing only the briefest hint of matters which, though not necessarily in their ultimate scientific minutiae, must be clearly comprehended in order to acquire a symmetrical and satisfactory view of the theme as a practical collation of facts to be remembered, analyzed, applied, and utilized.

It was the great Bacon who wrote: "The human body may be compared, from its complex and delicate organization, to a musical instrument of the most perfect construction, but exceedingly liable to derangement." In its degree the remark is equally applicable to the equine body, and if we would keep it in tune and profit by its harmonious action we must at least acquaint ourselves with the relations of its parts and the mode of their cooperation.

ANATOMY.

The bones, then, are the hard organs which in their connection and totality constitute the skeleton of an animal (see Plate XXIII). They are of various forms, three of which--the long, the flat, and the small--are recognized in the extremities. These are more or less regular in their form, but present upon their surfaces a variety of aspects, exhibiting in turn, according to the requirement of each case, a roughened or smooth surface, variously marked with grooves, crests, eminences, and depressions, for the necessary muscular attachments, and, as before mentioned, are connected by articulations and joints, of which some are immovable and others movable.

The substance of the bone is composed of a mass of combined earthy and animal matter surrounded by a fine, fibrous enveloping membrane (the periosteum) which is intimately adherent to the external surface of the bone, and is, in fact, the secreting membrane of the bony structure. The bony tissue proper is of two consistencies, the external portion being hard and "compact," and called by the latter term, while the internal, known as the "spongy" or "areolar tissue," corresponds to the descriptive terms. Those of the bones that possess this latter consistency contain also, in their spongy portion, the medullary substance known as marrow, which is deposited in large quantities in the interior of the long bones, and especially where a central cavity exists, called, for that reason, the medullary cavity. The nourishment of the bones is effected by means of what is known as the nutrient foramen, an opening established for the passage of the blood vessels which convey the nourishment necessary to the interior of the organ. Concerning the nourishment of the skeleton, there are other minutiae, such as the venous arrangement and the classification of their arterial vessels into several orders, which, though of interest as an abstract study, are not of sufficient practical value to refer to here.

The active organs of locomotion, the muscles (see Plate XXIII), speaking generally, form the fleshy covering of the external part of the skeleton and surround the bones of the extremities. They vary greatly in shape and size, being flat, triangular, long, short, or broad, and are variously and capriciously named, some from their shape, some from their situation, others from their use; and thus we have abductors and adductors--the pyramidal, orbicular, the digastricus, the vastus, and so on. Those which are under the control of the will, known as the voluntary muscles, appear in the form of fleshy structures, red in color, and with fibers of various degrees of fineness, and are composed of fasciculi, or bundles of fibers, united by connective or cellular tissue, each fasciculus being composed of smaller ones but united in a similar manner to compose the larger formations, each of which is enveloped by a structure of similar nature known as the sarcolemma. Many of the muscles are united to the bones by the direct contact of their fleshy fibers, but in other instances the body of the muscle is more or less gradually transformed into a cordy or membranous structure known as the tendon or sinew, and the attachment is made by the very short fibrous threads through the medium of a long tendinous band, which, passing from a single one to several others of the bones, effects its object at a point far distant from its original attachment. In thus carrying its action from one bone to another, or from one region of a limb to another, these tendons must necessarily have smooth surfaces over which to glide, either upon the bones themselves or formed at their articulations, and this need is supplied by the secretion of the synovial fluid, a yellowish, unctuous substance, furnished by a peculiar tendinous synovial sac designed for the purpose.

Illustrations in point of the agency of the synovial fluid in assisting the sliding movements of the tendons may be found under their various forms at the shoulder joint, at the upper part of the bone of the arm, at the posterior part of the knee joint, and also at the fetlocks, on their posterior part.

As the tendons, whether singly or in company with others, pass over these natural pulleys they are retained in place by strong, fibrous bands or sheaths, which are by no means exempt from danger of injury, as will be readily inferred from a consideration of their important special use as supports and reenforcements of the tendons themselves, with which they must necessarily share the stress of whatever force or strain is brought to bear upon both or either.

We have referred to that special formation of the external surface of a bone by which it is adapted to form a joint or articulation, either movable or fixed, and a concise examination of the formation and structure of the movable articulations will here be in place. These are formed generally by the extremities of the long bones, or may exist on the surfaces of the short ones. The points or regions where the contact occurs are denominated the articular surface, which assumes from this circumstance a considerable variety of aspect and form, being in one case comparatively flat and another elevated; or as forming a protruding head or knob, with a distinct convexity; and again presenting a corresponding depression or cavity, accurately adapted to complete, by their coaptation, the ball-and-socket joint. The articulation of the arm and shoulder is an example of the first kind, while that of the hip with the thigh bone is a perfect exhibition of the latter.

The structure whose office it is to retain the articulating surfaces in place is the ligament. This is usually a white, fibrous, inelastic tissue; sometimes, however, it is elastic in character and yellowish. In some instances it is funicular shaped or corded, serving to bind more firmly together the bones to which its extremities are attached; in others it consists of a broad membrane, wholly or partially surrounding the broad articulations, and calculated rather for the protection of the cavity from intrusion by the air than for other security. This latter form, known as capsular, is usually found in connection with joints which possess a free and extended movement. The capsular and funicular ligaments are sometimes associated, the capsular appearing as a membranous sac wholly or partially inclosing the joint, the funicular, here known as an interarticular ligament, occupying the interior, and thus securing the union of the several bones more firmly and effectively than would be possible for the capsular ligament unassisted.

The universal need which pertains to all mechanical contrivances of motion has not been forgotten while providing for the perfect working of the interesting piece of living machinery which performs the function of locomotion, as we are contemplating it, and nature has consequently provided for obviating the evils of attrition and friction and insuring the easy play and smooth movement of its parts by the establishment of the secretion of the synovia, the vital lubricant of which we have before spoken, as a yellow, oily, or rather glairy secretion, which performs the indispensable office of facilitating the play of the tendons over the joints and certain given points of the bones. This fluid is deposited in a containing sac, the lining (serous) membrane of which forms the secreting organ. This membrane is of an excessively sensitive nature, and while it lines the inner face of the ligaments, both capsular and fascicular, it is attached only upon the edges of the bones, without extending upon their length, or between the layers of cartilage which lie between the bones and their articular surfaces.

Our object in thus partially and concisely reviewing the structure and condition of the essential organs of locomotion has been rather to outline a sketch which may serve as a reference chart of the general features of the subject than to offer a minute description of the parts referred to. Other points of interest will receive proper attention as we proceed with the illustration of our subject and examine the matters which it most concerns us to bring under consideration. The foundation of facts which we have thus far prepared will be found sufficiently broad, we trust, to include whatever may be necessary to insure a ready comprehension of the essential matters which are to follow as our review is carried forward to completion. What we have said touching these elementary truths will probably be sufficient to facilitate a clear understanding of the requirements essential to the perfection and regularity which characterize the normal performance of the various movements that result in the accomplishment of the action of locomotion. So long as the bones, the muscles and their tendons, the joints with their cartilages, their ligaments, and their synovial structure, the nerves and the controlling influences which they exercise over all, with the blood vessels which distribute to every part, however minute, the vitalizing fluid which sustains the whole fabric in being and activity--so long as these various constituents and adjuncts of animal life preserve their normal exemption from disease, traumatism, and pathological change, the function of locomotion will continue to be performed with perfection and efficiency.

On the other hand, let any element of disease become implanted in one or several of the parts destined for combined action, any change or irregularity of form, dimensions, location, or action occur in any portion of the apparatus--any obstruction or misdirection of vital power take place, any interference with the order of the phenomena of normal nature, any loss of harmony and lack of balance be betrayed--and we have in the result the condition of lameness.

DEFINITION OF LAMENESS.

Physiology.--Comprehensively and universally considered, then, the term lameness signifies any irregularity or derangement of the function of locomotion, irrespective of the cause which produced it or the degree of its manifestation. However slightly or severely it may be exhibited, it is all the same. The nicest observation may be demanded for its detection, and it may need the most thoroughly trained powers of discernment to identify and locate it, as in cases in which the animal is said to be fainting, tender, or to go sore. On the contrary, the patient may be so far affected as to refuse utterly to use an injured leg, and under compulsory motion keep it raised from the ground, and prefer to travel on three legs rather than to bear any portion of his weight upon the afflicted member. In these two extremes, and in all the intermediate degrees, the patient is simply lame--pathognomonic minutiae being considered and settled in a place of their own.

This last condition of disabled function--lameness on three legs--and many of the lower degrees of simple lameness are very easy of detection, but the first, or mere tenderness or soreness, may be very difficult to identify, and at times very serious results have followed from the obscurity which has enveloped the early stages of the malady. For it may easily occur that in the absence of the treatment which an early correct diagnosis would have indicated, an insidious ailment may so take advantage of the lapse of time as to root itself too deeply into the economy to be subverted, and become transformed into a disabling chronic case, or possibly one that is incurable and fatal. Hence the impolicy of depreciating early symptoms because they are not accompanied with distinct and pronounced characteristics, and from a lack of threatening appearances inferring the absence of danger. The possibilities of an ambush can never be safely ignored. An extra caution costs nothing, even if wasted. The fulfillment of the first duty of a practitioner, when introduced to a case, is not always an easy task, though it is too frequently expected that the diagnosis, or "what is the matter" verdict, will be reached by the quickest and surest kind of an "instantaneous process" and a sure prognosis, or "how will it end," guessed at instanter.

Usually the discovery that the animal is becoming lame is comparatively an easy matter to a careful observer. Such a person will readily note the changes of movements which will have taken place in the animal he has been accustomed to drive or ride, unless they are indeed slight and limited to the last degree. But what is not always easy is the detection, after discovering the fact of an existing irregularity, of the locality of its point of origin, and whether its seat be in the near or off leg, or in the fore or the hind part of the body. These are questions too often wrongly answered, notwithstanding the fact that with a little careful scrutiny the point may be easily settled. The error, which is too often committed, of pronouncing the leg upon which the animal travels soundly as the seat of the lameness, is the result of a misinterpretation of the physiology of locomotion in the crippled animal. Much depends upon the gait with which the animal moves while under examination. The act of walking is unfavorable for accurate observation, though, if the animal walks on three legs, the decision is easy to reach. The action of galloping will often, by the rapidity of the muscular movements and their quick succession, interfere with a nice study of their rhythm, and it is only under some peculiar circumstances that the examination can be safely conducted while the animal is moving with that gait. It is while the animal is trotting that the investigation is made with the best chances of an intelligent decision, and it is while moving with that gait, therefore, that the points should be looked for which must form the elements of the diagnosis.

Our first consideration should be the physiology of normal or healthy locomotion, that thence we may the more easily reach our conclusions touching lameness, or that which is abnormal, and by this process we ought to succeed in obtaining a clew to the solution of the first problem, to wit, in which leg is the seat of the lameness?

A word of definition is here necessary, in order to render that which follows more easily intelligible. In veterinary nomenclature each two of the legs, as referred to in pairs, is denominated a biped. Of the four points occupied by the feet of the animal while standing at rest, forming a square, the two fore legs are known as the anterior biped; the two hinder, the posterior; the two on one side, the lateral: and one of either the front or hind biped with the opposite leg of the hind or front biped will form the diagonal biped.

Considering, as it is proper to do, that in a condition of health each separate biped and each individual leg is required to perform an equal and uniform function and to carry an even or equal portion of the weight of the body, it will be readily appreciated that the result of this distribution will be a regular, evenly balanced, and smooth displacement of the body thus supported by the four legs, and that therefore, according to the rapidity of the motion in different gaits, each single leg will be required at certain successive moments to bear the weight which had rested upon its congener while it was itself in the air, in the act of moving; or, again, two different legs of a biped may be called upon to bear the weight of the two legs of the opposite biped while also in the air in the act of moving.

To simplify the matter by an illustration, the weight of an animal may be placed at 1,000 pounds, of which each leg, in a normal and healthy condition, supports while at rest 250 pounds. When one of the fore legs is in action, or in the air, and carrying no weight, its 250 pounds share of the weight will be thrown upon its congener, or partner, to sustain. If the two legs of a biped are both in action and raised from the ground, their congeners, still resting in inaction, will carry the total weight of the other two, or 500 pounds. And as the succession of movements continues, and the change from one leg to another or from one biped to another, as may be required by the gait, proceeds, there will result a smooth, even, and equal balancing of active movements, shifting the weight from one leg or one biped to another, with symmetrical precision, and we shall be presented with an interesting example of the play of vital machanics in a healthy organization.

Much may be learned from the accurate study of the action of a single leg. Normally, its movements will be without variation or failure. When at rest it will easily sustain the weight assigned to it without showing hesitancy or betraying pain, and when it is raised from the ground in order to transfer the weight to its mate it will perform the act in such manner that when it is again placed upon the ground to rest it will be with a firm tread, indicative of its ability to receive again the burden to be thrown back upon it. In planting it upon the ground or raising it again for the forward movement while in action, and again replanting it upon the earth, each movement will be the same for each leg and for each biped, whether the act is that of walking or trotting, or even of galloping. In short, the regular play of every part of the apparatus will testify to the existence of that condition of orderly soundness and efficient activity eloquently suggestive of the condition of vital integrity which is simply but comprehensively expressed by the terms health and soundness.

But let some change, though slight and obscure, occur among the elements of the case; some invisible agency of evil intrude among the harmonizing processes going forward; any disorder occur in the relations of cooperating parts; anything appear to neutralize the efficiency of vitalizing forces; any disability of a limb to accept and to throw back upon its mate the portion of the weight which belongs to it to sustain--present itself, whether as the effect of accident or otherwise; in short, let anything develop which tends to defeat the purpose of nature in organizing the locomotive apparatus and we are confronted at once by that which may be looked upon as a cause of lameness.

Not the least of the facts which it is important to remember is that it is not sufficient to look for the manifestation of an existing discordance in the action of the affected limb alone, but that it is shared by the sound one and must be searched for in that as well as the halting member, if the hazard of an error is to be avoided. The mode of action of the leg which is the seat of the lameness will vary greatly from that which it exhibited when in a healthy condition, and the sound leg will also offer important modifications in the same three particulars before alluded to, to wit, that of resting on the ground, that of its elevation and forward motion, and that of striking the ground again when the full action of stepping is accomplished. Inability in the lame leg to sustain weight will imply excessive exertion by the sound one, and lack of facility or disposition to rest the lame member on the ground will necessitate a longer continuance of that action on the sound side. Changes in the act of elevating the leg, or of carrying it forward, or in both, will present entirely opposite conditions between the two. The lame member will be elevated rapidly, moved carefully forward, and returned to the ground with caution and hesitancy, and the contact with the earth will be effected as lightly as possible, while the sound limb will rest longer on the ground, move boldly and rapidly forward, and strike the ground promptly and forcibly. All this is due to the fact that the sound member carries more than its normal, healthy share of the weight of the body, a share which may be in excess from 1 to 250 pounds, and thus bring its burden to a figure varying from 251 to 500 pounds, all depending upon the degree of the existing lameness, whether it is simply a slight tenderness or soreness, or whether the trouble has reached a stage which compels the patient to the awkwardness of traveling on three legs.

That all this is not mere theory, but rests on a foundation of fact may be established by observing the manifestations attending a single alteration in the balancing of the body. In health the support and equilibrium of that mass of the body which is borne by the fore legs is equalized and passes by regular alternations from the right to the left side and vice versa. But if the left leg, becoming disabled, relieves itself by leaning, as it were, on the right, the latter becomes, consequently, practically heavier and the mass of the body will incline or settle upon that side. Lameness of the left side, therefore, means dropping or settling on the right and vice versa. We emphasize this statement and insist upon it, the more from the frequency of the instances of error which have come under our notice, in which persons have insisted upon their view that the leg which is the seat of the lameness is that upon which he drops and which the animal is usually supposed to favor.

HOW TO DETECT THE SEAT OF LAMENESS.

Properly appreciating the remarks which have preceded, and fully comprehending the modus operandi and the true pathology of lameness, but little remains to be done in order to reach an answer to the question as to which side of the animal is the seat of the lameness, except to examine the patient while in action. We have already stated our reasons for preferring the movement of trotting for this purpose. In conducting such an examination the animal should be unblanketed, and held by a plain halter in the hands of a man who knows how to manage his paces, and the trial should always be made over a firm, hard road whenever it is available. He is to be examined from various positions--from before, from behind, and from each side. Watching him as he approaches, as he passes by, and as he recedes, the observer should carefully study that important action which we have spoken of as the dropping of the body upon one extremity or the other, and this can readily be detected by attending closely to the motions of the head and of the hip. The head drops on the same side on which the mass of the body will fall, dropping toward the right when the lameness is in the left fore leg, and the hip dropping in posterior lameness, also on the sound leg, the reversal of the conditions, of course, producing reversed effects. In other words, when the animal in trotting exhibits signs of irregularity of action, or lameness, and this irregularity is accompanied with dropping or nodding the head, or depressing the hip on the right side of the body, at the time the feet of the right side strike the ground, the horse is lame on the left side. If the dropping and nodding are on the near side the lameness is on the off side.

In a majority of cases, however, the answer to the first question relating to the lameness of a horse is, after all, not a very difficult task. There are two other problems in the case more difficult of solution and which often require the exercise of a closer scrutiny, and draw upon all the resources of the experienced practitioner to settle satisfactorily. That a horse is lame in a given leg may be easily determined, but when it becomes necessary to pronounce upon the query as to what part, what region, what structure is affected, the easy part of the task is over, and the more difficult and important, because more obscure, portion of the investigation has commenced--except, of course, in cases of which the features are too distinctly evident to the senses to admit of error. It is true that by carefully noting the manner in which a lame leg is performing its functions, and closely scrutinizing the motions of the whole extremity, and especially of the various joints which enter into its structure; by minutely examining every part of the limb; by observing the outlines; by testing the change, if any, in temperature and the state of the sensibility--all these investigations may guide the surgeon to a correct localization of the seat of trouble, but he must carefully refrain from the adoption of a hasty conclusion, and, above all, assure himself that he has not failed to make the foot, of all the organs of the horse the most liable to injury and lesion, the subject of the most thorough and minute examination of all the parts which compose the suffering extremity.

The greater liability of the foot than of any other part of the extremities to injury from casualties, natural to its situation and use, should always suggest the beginning of an inquiry, especially in an obscure case of lameness at that point. Indeed the lameness may have an apparent location elsewhere when that is the true seat of the trouble, and the surgeon who, while examining his lame patient, discovers a ringbone, and convincing himself that he has encountered the cause of the disordered action suspends his investigation without subjecting the foot to a close scrutiny, at a later day when regrets will avail nothing, may deeply regret his neglect and inadvertence. As in human pathological experience, however, there are instances when inscrutable diseases will deliver their fatal messages, while leaving no mark and making no sign by which they might be identified and classified, so it will happen that in the humbler animals the onset and progress of mysterious and unrecognizable ailments will at times baffle the most skilled veterinarian, and leave our burden-bearing servants to succumb to the inevitable, and suffer and perish in unrelieved distress.

DISEASES OF BONES.

PERIOSTITIS, OSTITIS, AND EXOSTOSIS.

From the closeness and intimacy of the connection existing between the two principal elements of the bony structure while in health, it frequently becomes exceedingly difficult, when a state of disease has supervened, to discriminate accurately as to the part primarily affected and to determine positively whether the periosteum or the body of the bone is originally implicated. Yet a knowledge of the fact is often of the first importance, in order to obtain a favorable result from the treatment to be instituted. It is, however, quite evident that in a majority of instances the bony growths which so frequently appear on the surface of their structure, to which the general term of exostosis is applied, have had their origin in an inflammation of the periosteum, or enveloping membrane, and known as periostitis. However this may be, we have as a frequent result, sometimes on the body of the bone, sometimes at the extremities, and sometimes involving the articulation itself, certain bony growths, or exostoses, known otherwise by the term of splint, ringbone, and spavin, all of which, in an important sense, may be finally referred to the periosteum as their nutrient source and support, at least after their formation, if not for their incipient existence.

Cause.--It is certain that inflammation of the periosteum is frequently referable to wounds and bruises caused by external agencies, and it is also true that it may possibly result from the spreading inflammation of surrounding diseased tissues, but in any case the result is uniformly seen in the deposit of a bony growth, more or less diffuse, sometimes of irregular outline, and at others projecting distinctly from the surface from which it springs, as so commonly presented in the ringbone and the spavin.

Symptoms.--This condition of periostitis is often difficult to determine. The signs of inflammation are so obscure, the swelling of the parts so insignificant, any increase of heat so imperceptible, and the soreness so slight, that even the most acute observer may fail to find the point of its existence, and it is often long after the discovery of the disease itself that its location is positively revealed by the visible presence of the exostosis. Yet the first question had been resolved, in discovering the fact of the lameness, while the second and third remained unanswered, and the identification of the affected limb and the point of origin of the trouble remained unknown until their palpable revelation to the senses.

Treatment.--When, by careful scrutiny, the ailment has been located, a resort to treatment must be had at once, in order to prevent, if possible, any further deposit of the calcareous structure and increase of the exostotic growth. With this view the application of water, either warm or cold, rendered astringent by the addition of alum or sugar of lead, will be beneficial. The tendency to the formation of the bony growth, and the increase of its development after its actual formation, may often be checked by the application of a severe blister of Spanish fly. The failure of these means and the establishment of the diseased process in the form of chronic periostitis cause various changes in the bone covered by the disordered membrane, and the result may be softening, degeneration, or necrosis, but more usually it is followed by the formation of the bony growths referred to, on the cannon bone, the coronet, the hock, etc.

SPLINTS.

We first turn our attention to the splint, as certain bony enlargements that are developed on the cannon bone, between the knee or the hock and the fetlock joint, are called. (See Plate XXV.) They are found on the inside of the leg, from the knee, near which they are frequently found, downward to about the lower third of the principal cannon bone. They are of various dimensions, and are readily perceptible both to the eye and to the touch. They vary considerably in size, ranging from that of a large nut downward to very small proportions. In searching for them they may be readily detected by the hand if they have attained sufficient development in their usual situation, but must be distinguished from a small, bony enlargement that may be felt at the lower third of the cannon bone, which is neither a splint nor a pathological formation of any kind, but merely the buttonlike enlargement at the lower extremity of the small metacarpal or splint bone.

We have said that splints are to be found on the inside of the leg. This is true as a general statement, but it is not invariably so, for they occasionally appear on the outside. It is also true that they appear most commonly on the fore legs, but this is not exclusively the case, because they may at times be found on both the inside and outside of the hind leg. Usually a splint forms only a true exostosis, or a single bony growth, with a somewhat diffuse base, but neither is this invariably the case. In some instances they assume more important dimensions, and pass from the inside to the outside of the bone, on its posterior face, between that and the suspensory ligament. This form is termed the pegged splint, and constitutes a serious and permanent deformity, in consequence of its interference with the play of the fibrous cord which passes behind it, becoming thus a source of continual irritation and consequently of permanent lameness.

Symptoms.--A splint may thus frequently become a cause of lameness though not necessarily in every instance, but it is a lameness possessing features peculiar to itself. It is not always continuous, but at times assumes an intermittent character, and is more marked when the animal is warm than when cool. If the lameness is near the knee joint, it is very liable to become aggravated when the animal is put to work, and the gait acquires then a peculiar character, arising from the manner in which the limb is carried outward from the knees downward, which is done by a kind of abduction of the lower part of the leg. Other symptoms, however, than the lameness and the presence of the splint, which is its cause, may be looked for in the same connection as those which have been mentioned as pertaining to certain evidences of periostitis, in the increase of the temperature of the part, with swelling and probably pain on pressure. This last symptom is of no little importance, since its presence or absence has in many cases formed the determining point in deciding a question of difficult diagnosis.

Cause.--A splint being one of the results of periostitis, and the latter one of the effects of external hurts, it naturally follows that the parts which are most exposed to blows and collisions will be those on which the splint will most commonly be found, and it may not be improper, therefore, to refer to hurts from without as among the common causes of the lesion. But other causes may also be productive of the evil, and among these may be mentioned the over-straining of an immature organism by the imposition of excessive labor upon a young animal at a too early period of his life. The bones which enter into the formation of the cannon are three in number, one large and two smaller, which, during the youth of the animal, are more or less articulated, with a limited amount of mobility, but which become in maturity firmly joined by a rigid union and ossification of their interarticular surface. If the immature animal is compelled, then, to perform exacting tasks beyond his strength, the inevitable result will follow in the muscular straining, and perhaps tearing asunder of the fibers which unite the bones at their points of juncture, and it is difficult to understand how inflammation or periostitis can fail to develop as the natural consequence of such local irritation. If the result were deliberately and intelligently designed, it could hardly be more effectually accomplished.

The splint is an object of the commonest occurrence--so common, indeed, that in large cities a horse which can not exhibit one or more specimens upon some portion of his extremities is one of the rarest of spectacles. Though it is in some instances a cause of lameness, and its discovery and cure are sometimes beyond the ability of the shrewdest and most experienced veterinarians, yet as a source of vital danger to the general equine organization, or even of functional disturbance, or of practical inconvenience, aside from the rare exceptional cases which exist as mere samples of possibility, it can not be considered to belong to the category of serious lesions. The worst stigma that attaches to it is that in general estimation it is ranked among eyesores and continues indefinitely to be that and nothing different. The inflammation in which they originated, acute at first, either subsides or assumes the chronic form, and the bony growth becomes a permanence--more or less established, it is true, but doing no positive harm and not hindering the animal from continuing his daily routine of labor. All this, however, requires a proviso against the occurrence of a subsequent acute attack, when, as with other exostoses, a fresh access of acute symptoms may be followed by a new pathological activity, which shall again develop, as a natural result, a reappearance of the lameness.

Treatment.--It is, of course, the consideration of the comparative harmlessness of splints that suggests and justifies the policy of noninterference, except as they become a positive cause of lameness. And a more positive argument for such noninterference consists in the fact that any active and irritating treatment may so excite the parts as to bring about a renewed pathological activity, which may result in a reduplication of the phenomena, with a second edition, if not a second and enlarged volume, of the whole story. For our part, our faith is firm in the impolicy of interference, and this faith is founded on an experience of many years, during which our practice has been that of abstention.

Of course, there will be exceptional conditions which will at times indicate a different course. These will become evident when the occasions present themselves, and extraordinary forms and effects of inflammation and growth in the tumors offer special indications. But our conviction remains unshaken that surgical treatment of the operative kind is usually useless, if not dangerous. We have little faith in the method of extirpation except under very special conditions, among which that of diminutive size has been named; this seems in itself to constitute a sufficient negative argument. Even in such a case a resort to the knife or the gouge could scarcely find a justification, since no operative procedure is ever without a degree of hazard, to say nothing of the considerations which are always forcibly negative in any question of the infliction of pain and the unnecessary use of the knife.

If an acute periostitis of the cannon bone has been readily discovered, the treatment we have already suggested for that ailment is at once indicated, and the astringent lotions may be relied upon to bring about beneficial results. Sometimes, however, preference may be given to a lotion possessing a somewhat different quality, the alterative consisting of tincture of iodin applied to the inflamed spot several times daily. If the lameness persists under this mild course of treatment, it must, of course, be attacked by other methods, and we must resort to the cantharides ointment or Spanish-fly blister, as we have before recommended. Besides this, and producing an analogous effect, the compounds of biniodid of mercury are favored by some. It is prepared in the form of an ointment, consisting of 1 dram of the biniodid to 1 ounce of either lard or vaseline. It forms an excellent blistering and alterative application, and is of special advantage in newly formed or recently discovered exostosis.

It remains a pertinent query, however, and one which seems to be easily answered, whether a tumor so diminutive in size that it can be detected only by diligent search, and which is neither a disfigurement nor an obstruction to the motion of the limb, need receive any recognition whatever. Other modes of treatment for splints are recommended and practiced which belong strictly to the domain of operative veterinary surgery; among these are to be reckoned actual cauterization, or the application of the fire iron and the operation of periosteotomy. These are frequently indicated in the treatment of splints which have resisted milder means.

The mode of the development of their growth; their intimacy, greater or less, with both the large and the small cannon bones; the possibility of their extending to the back of these bones under the suspensory ligament; the dangerous complications which may follow the rough handling of the parts, with also a possibility, and, indeed, a probability, of their return after removal--these are the considerations which have influenced our judgment in discarding from our practice and our approval the method of removal by the saw or the chisel, as recommended by certain European veterinarians.

RINGBONES.

Ringbone is the designation of the exostosis which is found on the coronet and in the digital and phalangeal regions. (See Plate XXVI.) The name is appropriate, because the growth extends quite around the coronet, which it encircles in the manner of a ring, or perhaps because it often forms upon the back of that bone a regular osseous arch, through which the back tendons obtain a passage. The places where these growths are usually developed have caused their subdivision and classification into three varieties, with the designations of high, middle, and low, though much can be said as to the importance of the distinction. It is true that the ringbone or phalangeal exostosis may be found at various points on the foot, in one case forming a large bunch on the upper part and quite close to the fetlock joint; in another around the upper border of the hoof, or perhaps on the extreme front or on the very back of the coronet. The shape in which they commonly appear is favorable to their easy discovery, their form when near the fetlock usually varying too much from the natural outlines of the part when compared with those of the opposite side to admit of error in the matter. (See also page 439.)

A ringbone, when on the front of the foot, even when not very largely developed, assumes the form of a diffused convex swelling. If situated on the lower part, it will form a thick ring, encircling that portion of the foot immediately above the hoof; when found on the posterior part, a small, sharp osseous growth somewhat projecting, sometimes on the inside and sometimes on the outside of the coronet, may comprise the entire manifestation.

Cause.--As with splints, ringbones may result from severe labor in early life, before the process of ossification has been fully perfected; or they may be referred to bruises, blows, sprains, or other violence; injuries of tendons, ligaments, or joints also may be among the accountable causes.

It is certain that they may commonly be traced to diseases and traumatic lesions of the foot, and their appearance may be reasonably expected among the sequelae of an abscess of the coronet; or the cause may be a severe contusion resulting from calking, or a deep-punctured wound from picking up a nail or stepping upon any hard object of sufficiently irregular form to penetrate the sole.

Moreover, a ringbone may originate in heredity. This is a fact of no little importance in its relation to questions connected with the extensive interests of the stock breeder and purchaser.

That the hereditary transmission of constitutional idiosyncrasies is an active cause with regard to diseases in general, it would be absurd to assert, but we do say that a predisposition to contract ringbone through faulty conformation, such as long, thin pasterns with narrow joints and steep fetlocks, may be inherited in many cases, and in a smaller proportion of cases this predisposition may act as a secondary cause in the formation of ringbone.

The importance of this point when considered in reference to the policy which should be observed in the selection of breeding stock is obvious, and, as the whole matter is within the control of the owners and breeders, it will be their own fault if the unchecked transmission of ringbones from one equine generation to another is allowed to continue. It is our belief that among the diseases which are known for their tendency to perpetuate and repeat themselves by individual succession, those of the bony structures stand first, and the inference from such fact which would exclude every animal of doubtful soundness in its osseous apparatus from the stud list and the brood farm is too plain for argument.

Symptoms.--Periostitis of the phalanges is an ailment requiring careful exploration and minute inspection for its discovery, and is very liable to result in a ringbone of which lameness is the result. The mode of its manifestation varies according to the state of development of the diseased growth as affected by the circumstances of its location and dimensions. It is commonly of the kind which, in consequence of its intermittent character, is termed lameness when cool, having the peculiarity of exhibiting itself when the animal starts from the stable and of diminishing, if not entirely disappearing after some distance of travel, to return to its original degree, if not indeed a severer one, when he has again cooled off in his stable. The size of the ringbone does not indicate the degree to which it cripples the patient, but the position may, especially when it interferes with the free movement of the tendons which pass behind and in front of the foot. While a large ringbone will often interfere but little with the motion of the limb, a smaller growth, if situated under the tendon, may become the cause of considerable and continued pain.

A ringbone is doubtless a worse evil than a splint. Its growth, its location, its tendency to increased development, its exposure to the influence of causes of renewed danger, all tend to impart an unfavorable cast to the prognosis of a case and to emphasize the importance and the value of an early discovery of its presence and possible growth. Even when the discovery has been made, it is often the case that the truth has come to light too late for effectual treatment. Months may have elapsed after the first manifestation of the lameness before a discovery has been made of the lesion from which it has originated, and there is no recall for the lapsed time. And by the uncompromising seriousness of the discouraging prognosis must the energy and severity of the treatment and the promptness of its administration be measured. The periostitis has been overlooked; any chance that might have existed for preventing its advance to the chronic stage has been lost; the osseous formation is established; the ringbone is a fixed fact, and the indications are urgent and pressing.

Treatment.--The preventive treatment consists in keeping colts well nourished and in trimming the hoof and shoeing to balance the foot properly and thus prevent an abnormal strain on the ligaments. Even after the ringbone has developed, a cure may sometimes be occasioned by proper shoeing directed toward straightening the axis of the foot as viewed from the side by making the wall of the hoof from the coronet to the toe continuous with the line formed by the front of the pastern. So long as inflammation of the periosteum and ligaments remains, a sharp blister of biniodid of mercury and cantharides may do good if the animal is allowed to rest for four or five weeks. If this fails, some success may be accomplished by point firing in two or three lines over the ringbone. It is necessary to touch the hot iron well into the bone, as superficial firing does little good. When all these measures have failed to remove the lameness, or when the animal is not worth a long and uncertain treatment, a competent veterinarian should be engaged to perform double neurectomy, high or low, of the plantar nerves, or neurectomy of the median nerve as indicated by the seat of the lesion.

SIDEBONES.

On each side of the bone of the hoof--the coffinbone--there are normally two supplementary organs which are called the cartilages of the foot. They are soft, and though in a degree elastic, yet somewhat resisting, and are implanted on the lateral wings of the coffinbone. Evidently their office is to assist in the elastic expansion and contraction of the posterior part of the hoof, and their healthy and normal action doubtless contributes in an important degree to the perfect performance of the functions of that part of the leg. These organs are, however, liable to undergo a process of disease which results in an entire change in their properties, if not in their shape, by which they acquire a character of hardness resulting from the deposit of earthy substance in the intimate structure of the cartilage, and it is this change, when its consummation has been effected, that brings to our cognizance the diseased growth which has received the designation of sidebones. They are situated on one or both sides of the leg, bulging above the superior border of the hoof in the form of two hard bodies composed of ossified cartilage, irregularly square in shape and unyielding under the pressure of the fingers.

Cause.--Sidebones may be the result of a low inflammatory condition or of an acute attack as well, or may be caused by sprains, bruises, or blows; or they may have their rise in certain diseases affecting the foot proper, such as corns, quarter cracks, or quittor. The deposit of calcareous matter in the cartilage is not always uniform, the base of that organ near its line of union with the coffinbone being in some cases its limit, while at other times it is diffused throughout its substance, the size and prominence of the growth varying much in consequence.

Symptoms.--It would naturally be inferred that the degree of interference with the proper functions of the hoof which must result from such a pathological change would be proportioned to the size of the tumor, and that as the dimensions increase the resulting lameness would be the greater in degree. This, however, is not the fact. A small tumor while in a condition of acute inflammation during the formative stage may cripple a patient more severely than a much larger one in a later stage of the disease. In any case the lameness is never wanting, and with its intermittent character may usually be detected when the animal is cooled off after labor or exercise. The class of animals in which this feature of the disease is most frequently seen is that of the heavy draft horse and others similarly employed. There is a wide margin of difference in respect to the degrees of severity which may characterize different cases of sidebone. While one may be so slight as to cause no inconvenience, another may develop elements of danger which may involve the necessity of severe surgical interference.

Treatment.--The curative treatment should be similar to the prophylactic, and such means should be used as would tend to prevent the deposit of bony matters by checking the acute inflammation which causes it. The means recommended are the free use of the cold bath; frequent soaking of the feet, and at a later period treatment with iodin, either by painting the surface with the tincture several times daily or by applying an ointment made by mixing 1 dram of the crystals with 2 ounces of vaseline, rubbed in once a day for several days. If this proves to be ineffective, a Spanish-fly blister to which a few grains of biniodid of mercury have been added will effect in a majority of cases the desired result and remove the lameness. If finally this treatment is ineffectual the case must be relegated to the surgeon for the operation of neurectomy, or the free and deep application of the firing iron.

SPAVIN.

(Pls. XXVII-XXIX.)

This affection, popularly termed bone spavin, is an exostosis of the hock joint. The general impression is that in a spavined hock the bony growth should be seated on the anterior and internal part of the joint, and this is partially correct, as such a growth will constitute a spavin in the most nearly correct sense of the term. But an enlargement may appear on the upper part of the hock also, or possibly a little below the inner side of the lower extremity of the shank bone, forming what is known as a high spavin; or, again, the growth may form just on the outside of the hock and become an outside or external spavin. And, finally, the entire under surface may become the seat of the osseous deposit, and involve the articular face of all the bones of the hock, which again is a bone spavin. There would seem, then, to be but little difficulty in comprehending the nature of a bone spavin, and there would be none but for the fact that there are similar affections which may confuse one if the diagnosis is not very carefully made.

But the hock may be "spavined," while to all outward observation it still retains its perfect form. With no enlargement perceptible to sight or touch the animal may yet be disabled by an occult spavin, an anchylosis in fact, which has resulted from a union of several of the bones of the joint, and it is only those who are able to realize the importance of its action to the perfect fulfillment of the function of locomotion by the hind leg who can comprehend the gravity of the only prognosis which can be justified by the facts of the case--a prognosis which is essentially a sentence of serious import in respect to the future usefulness and value of the animal. For no disease, if we except those acute inflammatory attacks upon vital organs to which the patient succumbs at once, is more destructive to the usefulness and value of a horse than a confirmed spavin. Serious in its inception, serious in its progress, it is an ailment which, when once established, becomes a fixed condition which there is no known means of dislodging.

Cause.--The periostitis, of which it is nearly always a termination, is usually the effect of a traumatic cause operating upon the complicated structure of the hock, such as a sprain which has torn a ligamentous insertion and lacerated some of its fibers, or a violent effort in jumping, galloping, or trotting, to which the victim has been compelled by the torture of whip and spur while in use as a gambling implement by a sporting owner, under the pretext of "improving his breed"; the extra exertion of starting an inordinately heavy load, or an effort to recover his balance from a misstep, slipping upon an icy surface, or sliding with worn shoes upon a bad pavement, and other kindred causes. We can repeat here what we have before said concerning bones, in respect to heredity as a cause. From our own experience we know of equine families in which this condition has been transmitted from generation to generation, and animals otherwise of excellent conformation have been rendered valueless by the misfortune of a congenital spavin.

Symptoms.--The evil is one of the most serious character for other reasons, among which may be specified the slowness of its development and the insidiousness of its growth. Certain indefinite phenomena and alarming changes and incidents furnish usually the only portents of approaching trouble. Among these signs may be mentioned a peculiar posture assumed by the patient while at rest, and becoming at length so habitual that it can not fail to suggest the action of some hidden disorder. The posture is due to the action of the adductor muscles, the lower part of the leg being carried inward, and the heel of the shoe resting on the toe of the opposite foot. Then an unwillingness may be noticed in the animal to move from one side of the stall to the other. When driven he will travel, but stiffly, with a sort of sidelong gait between the shafts, and after finishing his task and resting again in his stall will pose with the toe pointing forward, the heel raised, and the hock flexed. Considerable heat and inflammation soon appear. The slight lameness which appears when backing out of the stall ceases to be noticeable after a short distance of travel.

A minute examination of the hock may then reveal the existence of a bony enlargement which may be detected just at the junction of the hock and the cannon bone, on the inside and a little in front, and tangible both to sight and touch. This enlargement, or bone spavin, grows rapidly and persistently and soon acquires dimensions which renders it impossible to doubt any longer its existence or its nature. Once established, its development continues under conditions of progress similar to those to which we have before alluded in speaking of other like affections. The argument advanced by some that because these bony deposits are frequently found on both hocks they are not spavins is fallacious. If they are discovered on both hocks, it proves merely that they are not confined to a single joint.

The characteristic lameness of bone spavin, as it affects the motion of the hock joint, presents two aspects. In one class of cases it is most pronounced when the horse is cool, in the other when he is at work. The first is characterized by the fact that when the animal travels the toe first touches the ground, and the heel descends more slowly, the motion of flexion at the hock taking place stiffly, and accompanied with a dropping of the hip on the opposite side. In the other case the peculiarity is that the lameness increases as the horse travels; that when he stops he seeks to favor the lame leg, and when he resumes his work soon after he steps much on his toe, as in the first variety.

As with sidebones, though for a somewhat different reason, the dimensions of the spavin and the degree of the lameness do not seem to bear any determinate relation, the most pronounced symptoms at times accompanying a very diminutive growth. The distinction between the two varieties of cool and warm, however, may easily be determined by remembering the fact that in most cases the first, or cool, is due to a simple exostosis, while the second is generally connected with disease of the articulation, such as ulceration of the articular surface--a condition which, as we proceed further, will receive our attention when we reach the subject of stringhalt.

An excellent test for spavin lameness, which may be readily applied, consists in lifting the affected leg from the ground for one or two minutes and holding the foot high so as to flex all the joints. An assistant, with the halter strap in his hand, quickly starts the animal off in a trot, when, if the hock joint is affected, the lameness will be so greatly intensified as to lead readily to a diagnosis.

Prognosis.--Having thus fully considered the history of bone spavin, we are prepared to give due weight to the reasons that exist for the adverse prognosis which we must usually feel compelled to pronounce when encountering it in practice, as well as to realize the importance of early discovery. It is but seldom, however, that the necessary advantage of this early knowledge can be obtained, and when the true nature of the trouble has become apparent it is usually too late to resort to the remedial measures which, if duly forewarned, a skillful practitioner might have employed. We are fully persuaded that but for the loss of the time wasted in the treatment of purely imaginary ailments very many cases of bone spavin might be arrested in their incipiency and their victims preserved for years of comfort for themselves and valuable labor to their owners.

Treatment.--To consider a hypothetical case: An early discovery of lameness has been made; that is, the existence of an acute inflammation--of periostitis--has been detected. The increased temperature of the parts has been observed, with the stiffened gait and the characteristic pose of the limb, and the question is proposed for solution, What is to be done? Even with only these comparatively doubtful symptoms--doubtful with the nonexpert--we should direct our treatment to the hock in preference to any other joint, since of all the joints of the hind leg it is this which is most liable to be attacked, a natural result from its peculiarities of structure and function. And in answer to the query, What is the first treatment indicated? We should answer rest--emphatically, and as an essential condition, rest. Whether only threatened, suspected, or positively diseased, the animal must be wholly released from labor, and it must be no partial or temporary quiet of a few days. In all stages and conditions of the disease, whether the spavin is nothing more than a simple exostosis, or whether accompanied with the complication of arthritis, there must be a total suspension of effort until the danger is over. Less than a month's quiet ought not to be thought of--the longer the better.

Good results may also be expected from local applications. The various lotions which cool the parts, the astringents which lower the tension of the blood vessels, the tepid fomentations which accelerate the circulation in the engorged capillaries, the liniments of various composition, the stimulants, the opiate anodynes, the sedative preparations of aconite, the alterative frictions of iodin--all these are recommended and prescribed by one or another. We prefer counterirritants, for the reason, among many others, that by the promptness of their action they tend to prevent the formation of the bony deposits. The lameness will often yield to the blistering action of cantharides, in the form of ointment or liniment, and to the alterative preparations of iodin or mercury. If the owner of a "spavined" horse really succeeds in removing the lameness, he has accomplished all that he is justified in hoping for; beyond this let him be well persuaded that a "cure" is impossible.

For this reason, moreover, he will do well to be on his guard against the patented "cures" which the traveling horse doctor may urge upon him, and withhold his faith from the circular of the agent who will deluge him with references and certificates. It is possible that nostrums may in some exceptional instances prove serviceable, but the greater number of them are capable of producing only injurious effects. The removal of the bony tumor can not be accomplished by any such means, and if a trial of these unknown compounds should be followed by complications no worse than the establishment of one or more ugly, hairless cicatrices, it will be well for both the horse and his owner.

Rest and counterirritation, with the proper medicaments, constitute, then, the prominent points in the treatment designed for the relief of bone spavin. Yet there are cases in which all the agencies and methods referred to seem to lack effectiveness and fail to produce satisfactory results. Either the rest has been prematurely interrupted or the blisters have failed to modify the serous infiltration, or the case in hand has some undiscernible characteristics which seem to have rendered the disease neutral to the agencies used against it. An indication of more energetic means is then presented, and free cauterization with the firing iron becomes necessary.

At this point a word of explanation in reference to this operation of firing may be appropriate for the satisfaction of any among our readers who may entertain an exaggerated idea of its severity and possible cruelty.

The operation is one of simplicity, but is nevertheless one which, in order to secure its benefits, must be reserved for times and occasions of which only the best knowledge and highest discretion should be allowed to judge. It is not the mere application of a hot iron to a given part of the body which constitutes the operation of firing. It is the methodical and scientific introduction of heat into the structure with a view to a given effect upon a diseased organ or tissue by an expert surgeon. The first is one of the degrees of mere burning. The other is scientific cauterization, and is a surgical manipulation which should be committed exclusively to the practiced hand of the veterinary surgeon.

Either firing alone or stimulation with blisters is of great efficacy for the relief of lameness from bone spavin. Failure to produce relief after a few applications and after allowing a sufficient interval of rest should be followed by a second or, if needed, a third firing.

In case of further failure there is a reserve of certain special operations which have been tried and recommended, among which those of cunean tenotomy, periosteotomy, the division of nervous branches, etc., may be mentioned. These, however, belong to the peculiar domain of the veterinary practitioner, and need not now engage our attention.

FRACTURES.

In technical language a fracture is a "solution of continuity in the structure or substance of a bone." It ranks among the most serious of the lesions to which the horse--or any animal--can be subject. It is a subject of special interest to veterinarians and horse owners in view of the fact that it occurs in such a variety of forms and subjects the patient to much loss of time, resulting in the suspension of his earning capacity. Though of less serious consequence in the horse than in man, it is always a matter of grave import. It is always slow and tedious in healing and is frequently of doubtful and unsatisfactory result.

This solution of continuity may take place in two principal ways. In the most numerous instances it includes the total thickness of the bone and is a complete fracture. In other cases it involves only a portion of the thickness of the bone, and for that reason is described as incomplete. If the bone is divided into two separate portions and the soft parts have received no injury, the fracture is a simple one, or it becomes compound if the soft parts have suffered laceration, and comminuted if the bones have been crushed or ground into fragments, many or few. The direction of the break also determines its further classification. Broken at a right angle, it is transverse; at a different angle it becomes oblique, and it may be longitudinal or lengthwise. In a complete fracture, especially of the oblique kind, there is a condition of great importance in respect to its effect upon the ultimate result of the treatment in the fact that from various causes, such as muscular contractions or excessive motion, the bony fragments do not maintain their mutual coaptation, but become separated at the ends, which makes it necessary to add another descriptive term--with displacement. These words again suggest the negative and introduce the term without displacement, when the facts justify that description. Furthermore, a fracture may be intra-articular or extra-articular, as it extends into a joint or otherwise, and, once more, intra-periosteal when the periosteum remains intact. Finally, there is no absolute limit to the use of descriptive terminology in the case.

The condition of displacement is largely influential in determining the question of treatment and as affecting the final result of a case of fracture. This, however, is dependent upon its location or whether its seat is in one or more of the axes of the bone, in its length, its breadth, its thickness, or its circumference. An incomplete fracture may also be either simple or comminuted. In the latter case the fragments are held together by the periosteum when it is intact; in that case the fracture belongs to the intra-periosteal class. At times, also, there is only a simple fissure or split in the bone, making a condition of much difficulty of diagnosis.

Causes.--Two varieties of originating cause may be recognized in cases of fracture. They are the predisposing and the occasional. As to the first, different species of animals differ in the degree of their liability. That of the dog is greater than that of the horse, and in horses the various questions of age, the mode of labor, the season of the year, the portion of the body most exposed, and the existence of ailments, local and general, are all to be taken into account.

Among horses, those employed in heavy draft work or that are driven over bad roads are more exposed than light-draft or saddle horses, and animals of different ages are not equally liable. Dogs and young horses, with those which have become sufficiently aged for their bones to have acquired an enhanced degree of frangibility, are more liable than those which have not exceeded the time of their prime. The season of the year is undoubtedly, though in an incidental way, an important factor in the problem of the etiology of these accidents, for though they may be observed at all times, it is during the months when the slippery condition of the icy roads renders it difficult for both men and beasts to keep their feet that they occur most frequently. The long bones, those especially which belong to the extremities, are most frequently the seat of fractures, from the circumstance of their superficial position, their exposure to contact and collision, and the violent muscular efforts involved both in their constant, rapid movement and their labor in the shafts or at the pole of heavy and heavily laden carriages.

The relation between sundry idiosyncrasies and diathesis and a liability to fractures is too constant and well-established a pathological fact to need more than a passing reference. The history of rachitis, of melanosis, and of osteoporosis, as related to an abnormal frangibility of the bones, is a part of our common medical knowledge. There are few persons who have not known of cases among their friends of frequent and almost spontaneous fractures, or at least of such as seem to be produced by the slightest and most inadequate violence, and there is no tangible reason for doubting an analogous condition in dividuals of the equine race. Among local predisposing causes mention must not be omitted of such bony diseases as caries, tuberculosis, and others of the same class.

Exciting, occasional, or "efficient" causes of fracture are in most instances external traumatisms, as violent contacts, collisions, falls, etc., or sudden muscular contractions. These external accidents are various in their character, and are usually associated with quick muscular exertion. A violent, ineffectual effort to move too heavy a load; a semispasmodic bracing of the frame to avoid a fall or resist a pressure; a quick jump to escape a blow; stopping too suddenly after speeding; struggling to liberate a foot from a rail, perhaps to be thrown in the effort--all these are familiar and easy examples of accidents happening hourly by which our equine servants become sufferers. We may add to these the fracture of the bones of the vertebrae, occurring when casting a patient for the purpose of undergoing a surgical operation, quite as much as the result of muscular contraction as of a preexisting diseased condition of the bones. A fracture occurring under these circumstances may be called with propriety indirect, while one which has resulted from a blow or a fall differently caused is of the direct kind.

Symptoms.--We now return to the first items in our classification of the varieties of fractures for the purpose of bringing them in turn under an orderly review, and our first examination will include those which belong to the first category, or the complete kind. Irregularity in the performance of the functions of the apparatus to which the fractured bone belongs is a necessary consequence of the existing lesion, and this is lameness. If the broken bone belongs to one of the extremities, the impossibility of the performance of its natural function in sustaining the weight of the body and contributing to the act of locomotion is usually complete, though the degree of disability will vary according to the kind of fracture and the bone which is injured. For example, a fracture of the cannon bone without displacement, or of one of the phalanges, which are surrounded and sustained by a complex fibrous structure, is, in a certain degree, not incompatible with some amount of resting on the foot. On the contrary, if the shank bone, or that of the forearm is the implicated member, it would be very difficult for the leg to exercise any agency whatever in the support of the body, and in a fracture of the lower jaw it would be obviously unreasonable to expect it to contribute materially to the mastication of feed.

It seldom happens that a fracture is not accompanied with a degree of deformity, greater or less, of the region or the leg affected. This is due to the exudation of the blood into the meshes of the surrounding tissues and to the displacement which occurs between the fragments of the bones, with subsequently the swelling which follows the inflammation of the surrounding tissues. The character of the deformity will mainly depend upon the manner in which the displacement occurs.

In a normal state of things the legs perform their movements with the joints as their only centers or bases of action, with no participation of intermediate points, while with a fracture the flexibility and motion which will be observed at unnatural points are among the most strongly characteristic signs of the lesion. No one need be told that, when the shaft of a limb is seen to bend midway between the joints, with the lower portion swinging freely, the leg is broken. There are still some conditions, however, in which the excessive mobility is not easy to detect. Such are the cases in which the fracture exists in a short bone, near a movable joint, or in a bone of a region where several short and small bones are united in a group, or even in a long bone the situation of which is such that the muscular covering prevents the visible manifestation of the symptom.

If the situation of a fracture precludes its discovery by means of this abnormal flexibility, other modes of detection remain. There is one method which is absolute and positive and which can be applied in by far the most, though not in all cases. This is crepitation, or the peculiar effect which is produced by the friction of the fractured surfaces one against another. Though discerned by the organs of hearing it can scarcely be called a sound, for the grating of the parts as the rubbing takes place is more felt than heard; however, there is no mistaking its import in cases favorable for the application of the test. The conditions in which it is not available are those of incomplete fracture, in which the mobility of the part is lacking, and those in which the whole array of phenomena are usually obscure. To obtain the benefit of this pathognomonic sign requires deliberate, careful, and gentle manipulation. Sometimes the slightest of movements will be sufficient for its development, after much rougher handling has failed to discover it. Perhaps the failure in the latter case is due to a sort of defensive spasmodic rigidity caused by the pain resulting from the rude interference.

More or less reactive fever is a usual accompaniment of a fracture. Ecchymosis in the parts is but a natural occurrence, and is more easily discovered in animals possessing a light-colored and delicate skin than in those of any other character.

There are difficulties in the way of the diagnosis of an incomplete fracture, even sometimes when there is a degree of impairment in the function of locomotion, with evidences of pain and swelling at the seat of lesion. There should then be a careful examination for evidences of a blow or other violence sufficient to account for the fracture, though very often a suspicion of its existence can be converted into a certainty only by a minute history of the patient if it can be obtained up to the moment of the occurrence of the injury. A diagnosis ought not to be hastily pronounced, and where good ground for suspicion exists it ought not to be rejected upon any evidence less than the best. We too often read of serious and fatal complications following careless conclusions in similar cases, among which we may refer to one instance of a complete fracture manifesting itself in an animal during the act of rising in his stall after a decision had been pronounced that he had no fracture at all.

Fractures are of course liable to complications, especially those which are of a traumatic character, such as extensive lacerations, tearing of tissues, punctures, contusions, etc. Unless these are in communication with the fracture itself the indication is to treat them simply as independent lesions upon other parts of the body. A traumatic emphysema at times causes trouble, and abscesses, more or less deep and diffused, may follow. In some cases small, bony fragments from a comminuted fracture, becoming loose and acting as foreign bodies, give rise to troublesome fistulous tracts. A frequent complication is hemorrhage, which often becomes of serious consequence. A fracture in close proximity to a joint may be accompanied with dangerous inflammations of important organs, and induce an attack of pneumonia, pleurisy, arthritis, etc., especially if near the chest; it may also cause luxations, or dislocations. Gangrene, as a consequence of contusions or of hemorrhage or of an impediment to the circulation, caused by unskillfully applied apparatus, must not be overlooked among the occasional incidents; nor must lockjaw, which is not an uncommon occurrence. Even founder, or laminitis, has been met with as the result of forced and long-continued immobility of the feet in the standing posture, as one of the involvements of unavoidably protracted treatment.

When a simple fracture has been properly treated and the broken ends of the bone have been securely held in coaptation, one of two things will occur. Either--and this is the more common event--there will be a union of the two ends by a solid cicatrix, the callus, or the ends will continue separated or become only partially united by an intermediate fibrous structure. In the first instance the fracture is consolidated or united; in the second there is a false articulation, or pseudarthrosis.

The time required for a firm union or true consolidation of a fracture varies with the character of the bone affected, the age and constitution of the patient, and the general conditions of the case. The union will be perfected earlier in a young than in an adult animal, and sooner in the latter than in the aged, and a general healthy condition is, of course, in every respect, an advantage.

The mode of cicatrization, or method of repair in lesions of the bones, has been a subject of much study among investigators in pathology, and has elicited various expressions of opinion from those high in authority. The weight of evidence and preponderance of opinion are about settled in favor of the theory that the law of reparation is the same for both the hard and the soft tissues. In one case a simple exudation of material, with the proper organization of newly formed tissue, will bring about a union by the first intention, and in another the work will be accompanied with suppuration, or union by the second intention, a process so familiar in the repair of the soft structures by granulation.

Considering the process in its simplest form, in a case in which it advances without interruption or complication to a favorable result, it may probably be correctly described in this wise:

On the occurrence of the injury an effusion of blood takes place between the ends of the bone. The coagulation of the fluid soon follows, and this, after a few days, undergoes absorption. There is then an excess of inflammation in the surrounding structure, which soon spreads to the bony tissue, when a true ostitis is established, and the compact tissue of the bone becomes the seat of a new vascular organization, and of a certain exudation of plastic lymph, appearing between the periosteum and the external surface of the bone, as well as on the inner side of the medullary cavity. After a few days the ends of the bone thus surrounded by this exudate become involved in it, and the lymph, becoming vascular, is soon transformed into cartilaginous, and in due time into bony, tissue.

Thus the time required for the consolidation of the fractured segments is divisible into two distinct periods. In the first they are surrounded by an external bony ring, and the medullary cavity is closed by a bony plug or stopper, constituting the period of the provisional callus. This is followed by the period of permanent callus, during which the process of converting the cartilaginous into the osseous form is going forward.

The restorative process is sooner completed in the carnivorous than in the herbivorous tribes. In the former the temporary callus may attain sufficient fineness of consistency for the careful use of the limb within four weeks, but with the latter a period of from six weeks to two months is not too long to allow before removing the supporting apparatus from the limb.

This, in general terms, represents the fact when the resources of nature have not been thwarted by untoward accidents, such as a want of vigor in the constitution of the patient or a lack of skill on the part of the practitioner, and especially when, from any cause, the bony fragments have not been kept in a state of perfect immobility and the constant friction has prevented the osseous union of the two portions. Failures and misfortunes are always more than possible, and instead of a solid and practicable bony union the sequel of the accident is sometimes a false joint, composed of mere flexible cartilage, a poor pseudarthrosis. The explanation of this appears to be that, first, the sharp edges of the ends of the bone disappear by becoming rounded at their extremities by friction and polishing against each other. Then follows an exudation of a plastic nature which becomes transformed into a cartilaginous layer of a rough, articular aspect. In this bony nuclei soon appear, and the lymph secreted between the segments thus transformed, instead of becoming truly ossified, is changed into a sort of fibrocartilaginous pouch, or capsular sac, in which a somewhat albuminous secretion, or pseudo-synovia, permits the movement to take place. Most commonly, however, in our animals, the union of the bony fragments is obtained wholly through the medium of a layer of fibrous tissue, and it is because the union has been accomplished by a ligamentous formation only that motion becomes practicable.

Prognosis.--The prognosis in a case of fracture in an animal is one of the gravest vital import to the patient, and therefore of serious pecuniary concern to his owner. The period has not long elapsed when to have received such a hurt was quite equivalent to undergoing a sentence of death for the suffering animal, and perhaps to-day a similar verdict is pronounced in many cases in which the exercise of a little mechanical ingenuity, with a due amount of careful nursing, might secure a contrary result and insure the return of the patient to his former condition of soundness and usefulness.

Treatment.--Considered per se, a fracture in an animal is in fact no less amenable to treatment than the same description of injury in any other living being. But the question of the propriety and expediency of treatment is dependent upon certain specific points of collateral consideration.

(1) The nature of the lesion is a point of paramount importance. A simple fracture occurring in a bone where the ends can be firmly secured in coaptation presents the most favorable condition for successful treatment. If it is that of a long bone, it will be the less serious if situated at or near the middle of its length than if it were in close proximity to a joint, from the fact that perfect immobility can rarely, in the latter case, be secured without incurring the risk of subsequent rigidity of the joint.

A simple is always less serious than a compound fracture. A comminuted is always more dangerous than a simple, and a transverse break is easier to treat than one which is oblique. The most serious are those which are situated on parts of the body in which it is difficult to obtain perfect immobility, and especially those which are accompanied with severe contusions and lacerations in the soft parts; the protrusion of fragments through the skin; the division of blood vessels by the broken ends of the bone; the existence of an articulation near the point to which inflammation is liable to extend; the luxation of a fragment of the bone; laceration of the periosteum; the presence of a large number of bony particles, the result of the crushing of the bone--all these are circumstances which discourage a favorable prognosis, and weigh against the hope of saving the patient for future usefulness.

Fractures which may be accounted curable are those which are not conspicuously visible, as those of the ribs, where displacements are either very limited or do not occur, the parts being kept in situ by the nature of their position, the shape of the bones, the articulations they form with the vertebra, the sternum, or their cartilages of prolongation; those of transverse processes of the lumbar vertebra; those of the bones of the face; those of the ilium; and that of the coffinbones. To continue the category, the following are evidently curable when their position and the character of the patient contribute to aid the treatment: Those of the cranium, in the absence of cerebral lesions; those of the jaws; of the ribs, with displacement; of the hip; and those of the bones of the leg in movable regions, but where their vertical position admits of perfect coaptation.

On the contrary, a compound, complicated, or comminuted, fracture, in whatever region it may be situated, may be counted incurable.

In treating fractures time is an important element and "delays are dangerous." Those of recent occurrence unite more easily and more regularly than older ones.

(2) As a general rule, fractures are less serious in animals of the smaller species than in those of more bulky dimensions. This influence of species will be readily appreciated when we realize that the difficulties involved in the treatment of the latter class have hardly any existence in connection with the former. The difference in weight and size, and consequent facility in handling and making the necessary applications of dressings and other appliances for the purpose of securing the indispensable immobility of the parts, and usually a less degree of uneasiness in the deportment of the patients are considerations in this connection of great weight.

(3) In respect to the utilization of the animal, the most obvious point in estimating the gravity of the case in a fracture accident is the certainty of the total loss of the services of the patient during treatment--certainly for a considerable period of time; perhaps permanently. For example, the fracture of the jaw of a steer just fattening for the shambles will involve a heavier loss than a similar accident to a horse. Usually the fracture of the bones of the extremities in a horse is a very serious casualty, the more so proportionately as the higher region of the limb is affected. In working animals it is exceedingly difficult to treat a fracture in such manner as to restore a limb to its original perfection of movement. A fracture of a single bone of an extremity in a breeding stallion or mare will not necessarily impair the value of the animal as a breeder. Other specifications under this head, though pertinent and more or less interesting, may be omitted.

(4) Age and temper are important factors of cure. A young, growing, robust patient whose vis vitae is active is amenable to treatment which one with a waning constitution and past mature energies would be unable to endure, and a docile, quiet disposition will act cooperatively with remedial measures which would be neutralized by the fractious opposition of a peevish and intractable sufferer.

The fulfillment of three indications is indispensable in all fractures. The first is the reduction, or the replacement, of the parts as nearly as possible in their normal position. The second is their retention in that position for a period sufficient for the formation of the provisional callus, and the third, which, in fact, is but an incident of the second, the careful avoidance of any accidents or causes of miscarriage which might disturb the curative process.

In reference to the first consideration, it must be remembered that the accident may befall the patient at a distance from his home, and his removal becomes the first duty to be attended to. Of course, this must be done as carefully as possible. If he can be treated on the spot, so much the better, though this is seldom practicable, and the method of removal becomes the question calling for settlement. But two ways present themselves--he must either walk or be carried. If the first, it is needless to say that every caution must be observed in order to obviate additional pain and to avoid any aggravation of the injury. Led slowly, and with partial support, if practicable, the journey will not always involve untoward results. If he is carried, it must be by means of a wagon, a truck, or an ambulance; the last being designed and adapted to the purpose, would, of course, be the most suitable vehicle. As a precaution which should never be overlooked, a temporary dressing should first be applied. This may be so done as for the time to answer all the purposes of the permanent adjustment and bandaging. Without thus securing the patient, a fracture of an inferior degree may be transformed to one of the severest kind, and, indeed, a curable changed to an incurable injury. We recall a case in which a fast-trotting horse, after running away in a fright caused by the whistle of a locomotive, was found on the road limping with excessive lameness in the off fore leg, and walked with comparative ease some 2 miles to a stable before being seen by a surgeon. His immediate removal in an ambulance was advised, but before that vehicle could be procured the horse lay down, and upon being made to get upon his feet was found with a well-marked comminuted fracture of the os suffraginis, with considerable displacement. The patient, however, after long treatment, made a comparatively good recovery and though with a large, bony deposit, a ringbone, was able to trot in the forties.

The two obvious indications in cases of fracture are reduction, or replacement, and retention.

In an incomplete fracture, where there is no displacement, the necessity of reduction does not exist. With the bone kept in place by an intact periosteum, and the fragments secured by the uninjured fibrous and ligamentous structure which surrounds them, there is no dislocation to correct. Reduction is also at times rendered impossible by the seat of the fracture itself, by its dimensions, alone, or by the resistance arising from muscular contraction. That is illustrated even in small animals, as in dogs, by the exceeding difficulty encountered in bringing together the ends of a broken femur or humerus, the muscular contractions being even in these animals sufficiently forcible to renew the displacement.

It is generally, therefore, only fractures of the long bones, and then at points not in close proximity to the trunk, that may be considered to be amenable to reduction. It is true that some of the more superficial bones, as those of the head, of the pelvis, and of the thoracic walls, may in some cases require special manipulations and appliances for their retention in their normal positions; hence the treatment of these and of a fractured leg can not be the same.

The methods of accomplishing reduction vary with the features of each case, the manipulations being necessarily modified to meet different circumstances. If the displacement is in the thickness of the bone, as in transverse fracture, the manipulation of reduction consists in applying constant pressure upon one of the fragments, while the other is kept steady in its place, the object of the pressure being the reestablishment of the exact coincidence of the two bony surfaces. If the displacement has taken place at an angle it will be sufficient in order to effect the reduction to press upon the summit, or apex, of the angle until its disappearance indicates that the parts have been brought into coaptation. This method is often practiced in the treatment of a fractured rib. In a longitudinal fracture, or when the fragments are pressed together by the contraction of the muscles to which they give insertion until they so overlap as to correspond by certain points of their circumference, the reduction is to be accomplished by effecting the movements of extension, counter extension, and coaptation. Extension is accomplished by making traction upon the lower portion of the limb. Counter extension consists in firmly holding or confining the upper or body portion in such manner, that it shall not be affected by the traction applied to the lower part. In other words, the operator, grasping the limb below the fracture, draws it down or away from the trunk, while he seeks not to draw away, but simply to hold the upper portion still until the broken ends of bone are brought to their natural relative positions, when the coaptation, which is thus effected, has only to be made permanent by the proper dressings to perfect the reduction.

In treating fractures in small animals the strength of the hand is usually sufficient for the required manipulations. In the fracture of the forearm of a dog, for example, while the upper segment is firmly held by one hand the lower may be grasped by the other and the bone itself made to serve the purpose of a lever to bring about the desired coaptation. In such case that is sufficient to overcome the muscular contraction and correct the overlapping or other malposition of the bones. If, however, the resistance can not be overcome in this way, the upper segment may be committed to an assistant for the management of the counter extension, leaving to the operator the free use of both hands for the further manipulation of the case.

If the reduction of fractures in small animals is an easy task, however, it is far from being so when the patient is a large animal whose muscular force is largely greater than that of several men combined. In such case resort must be had not only to superior numbers for the necessary force, but in many cases to mechanical aids. A reference to the manner of proceeding in a case of fracture with displacement of the forearm of a horse will illustrate the matter. The patient is first to be carefully cast, on the uninjured side, with ropes or a broad, leather strap about 18 feet long passed under and around his body and under the axilla of the fractured limb and secured at a point opposite to the animal and toward his back. This will form the mechanical means of counter extension. Another rope will then be placed around the inferior part of the leg below the point of fracture, with which to produce extension, and this will sometimes be furnished with a block and pulleys, in order to augment the power when necessary; there is, in fact, always an advantage in their use, on the side of steadiness and uniformity, as well as of increased power. It is secured around the fetlock or the coronet or, what is better, above the knee and nearer the point of fracture, and is committed to assistants. The traction on this should be firm, uniform, and slow, without relaxing or jerking, while the operator carefully watches the process. If the bone is superficially situated he is able, by the eye, to judge of any changes that may occur in the form or length of the parts under traction, and discovering, at the moment of its happening, the restoration of symmetry in the disturbed region he gently but firmly manipulates the place until all appearance of severed continuity has vanished. Sometimes the fact and the instant of restoration are indicated by a peculiar sound or "click" as the ends of the bones slip into contact, to await the next step of the restorative procedure.

The process is the same when the bones are covered with thick muscular masses except that it is attended with greater difficulties from the fact that the finger must be substituted for the eye and taxis must take the place of sight.

It frequently happens that perfect coaptation is prevented by the interposition, between the bony surfaces, of such substances as a small fragment of detached bone or a clot of blood; sometimes the extreme obliquity of the fracture, by permitting the bones to slip out of place, is the opposing cause. These are difficulties which can not always be overcome, even in small-sized animals, and still it is only when they are mastered that a correct consolidation can be looked for. Without it the continuity between the fragments will be by a deformed callus, the union will leave a shortened, crooked, or angular limb, and the animal will be disabled.

If timely assistance can be obtained, and the reduction accomplished immediately after the occurrence of the accident, that is the best time for it, but if it can not be attended to until inflammation has become established and the parts have become swollen and painful, time must be allowed for the subsidence of these symptoms before attempting the operation. A spasmodic, muscular contraction which sometimes interposes a difficulty may be easily overcome by subjecting the patient to general anesthesia, and need not, therefore, cause any loss of time. A tendency to this may also be overcome by the use of sedatives and antiphlogistic remedies.

The reduction of the fracture having been accomplished, the problem which follows is that of retention. The parts which have been restored to their natural position must be kept there, without disturbance or agitation, until the perfect formation of a callus, and it is here that ample latitude exists for the exercise of ingenuity and skill by the surgeon in the contrivance of the necessary apparatus. One of the most important of the conditions which are available by the surgeon in treating human patients is denied to the veterinarian in the management of those which belong to the animal tribes. This is position. The intelligence of the human patient cooperates with the instructions of the surgeon, in the case of the animal sufferer there is a continual antagonism between the parties, and the forced extension and fatiguing position which must for a considerable period be maintained as a condition of restoration require special and effective appliances to insure successful results. To obtain complete immobility is scarcely possible, and the surgeon must be content to reach a point as near as possible to that which is unattainable. For this reason, as will subsequently be seen, the use of slings and the restraint of patients in very narrow stalls is much to be preferred to the practice sometimes recommended of allowing entire freedom of motion by turning them loose in box stalls. Temporary and movable apparatus are not usually of difficult use in veterinary practice, but the restlessness of the patients and their unwillingness to submit quietly to the changing of the dressings render it obligatory to have recourse to permanent and immovable bandages, which should be retained without disturbance until the process of consolidation is complete.

The materials composing the retaining apparatus consist of oakum, bandages, and splints, with an agglutinating compound which forms a species of cement by which the different constituents are blended into a consistent mass to be spread upon the surface covering the locality of the fracture. Its components are black pitch, rosin, and Venice turpentine, blended by heat. The dressing may be applied directly to the skin, or a covering of thin linen may be interposed. A putty made with powdered chalk and the white of egg is recommended for small animals, though a mixture of sugar of lead and burnt alum with the albumen is preferred by others. Another formula is spirits of camphor, Goulard's extract, and albumen. Another recommendation is to saturate the oakum and bandages with an adhesive solution formed with gum arabic, dextrin, flour paste, or starch. This is advised particularly for small animals, as is also the silicate of soda. Dextrin mixed while warm with burnt alum and alcohol cools and solidifies into a stony consistency, and is preferable to plaster of Paris, which is less friable and has less solidity, besides being heavier and requiring constant additions as it becomes older. Starch and plaster of Paris form another good compound.

In applying the dressing the leg is usually padded with a cushion of oakum thick and soft enough to equalize the irregularities of the surface and to form a bedding for the protection of the skin from chafing. Over this the splints are placed. The material for these is, variously, pasteboard, thin wood, bark, laths, gutta-percha, strips of thin metal, as tin or perhaps sheet iron. They should be of sufficient length not only to cover the region of the fracture but to extend sufficiently above and below to render the immobility more nearly complete than in the surrounding joints. The splints, again, are covered with cloth bandages--linen preferably--soaked in a glutinous mixture. These bandages are to be carefully applied, with a perfect condition of lightness. They are usually made to embrace the entire length of the leg in order to avoid the possibility of interference with the circulation of the extremity as well as for the prevention of chafing. They should be rolled from the lower part of the leg upward and carefully secured against loosening. In some instances suspensory bandages are recommended, but except for small animals our experience does not justify a concurrence in the recommendation.

These permanent dressings always need careful watching with reference to their immediate effect upon the region they cover, especially during the first days succeeding that of their application. Any manifestation of pain, or any appearance of swelling above or below, or any odor suggestive of suppuration should excite suspicion, and a thorough investigation should follow without delay. The removal of the dressing should be performed with great care, and especially so if time enough has elapsed since its application to allow of a probability of a commencement of the healing process or the existence of any points of consolidation. With the original dressing properly applied in its entirety in the first instance, the entire extremity will have lost all chance of mobility, and the repairing process may be permitted to proceed without interference. There will be no necessity and there need be no haste for removal or change except under such special conditions as have just been mentioned, or when there is reason to judge that solidification has become perfect, or for the comfort of the animal, or for its readaptation in consequence of the atrophy of the limb from want of use. Owners of animals are often tempted to remove a splint or bandage prematurely at the risk of producing a second fracture in consequence of the failure of the callus properly to consolidate.

The method of applying the splints which we have described refers to the simple variety only. In a compound case the same rules must be observed, with the modification of leaving openings through the thickness of the dressing, opposite the wound, in order to permit the escape of pus and to secure access to the points requiring the application of treatment.

FRACTURE OF CRANIAL BONES.

Fractures of the cranial bones in large animals are comparatively rare, though the records are not destitute of cases. When they occur, it is as the result of external violence, the sufferers being usually run-aways which have come in collision with a wall or a tree or other obstruction, or it may occur in those which in pulling upon the halter have broken it with a jerk and been thrown backward, as may occur in rearing too violently. Under these conditions we have witnessed fractures of the parietal, of the frontal, and of the sphenoid bones. These fractures may be of both the complete and the incomplete kinds, which indeed is usually the case with those of the flat bones, and they are liable to be complicated with lacerations of the skin, in consequence of which they are easily brought under observation. When the fact is otherwise and the skin is intact, however, the diagnosis becomes difficult.

Symptoms.--The incomplete variety may be unaccompanied with any special symptoms, but in the complete kind one of the bony plates may be so far detached as to press upon the cerebral substance with sufficient force to produce serious nervous complications. When the injury occurs at the base of the cranium hemorrhage may be looked for, with paralytic symptoms, and when these are present the usual termination is death. It may happen, however, that the symptoms of an apparently very severe concussion may disappear, resulting in an early and complete recovery, and the surgeon will therefore do well to avoid undue haste in venturing upon a prognosis. In fractures of the orbital or the zygomatic bones the danger is less pressing than with injuries otherwise located about the head.

Treatment.--The treatment of cranial fractures is simple, though involving the best skill of an experienced surgeon. When incomplete hardly any interference is needed; even plain bandaging may usually be dispensed with. In the complete variety the danger to be combated is compression of the brain, and attention to this indication must not be delayed. The means to be employed are the trephining of the skull over the seat of the fracture and the elevation of the depressed bone or the removal of the portion which is causing the trouble. Fragments of bone in comminuted cases, bony exfoliations, collections of fluid, or even protruding portions of the brain substance must be carefully cleansed away and a simple bandage so applied as to facilitate the application of subsequent dressings.

FRACTURES OF THE BONES OF THE FACE.

In respect to their origin--usually traumatic--these injuries rank with the preceding, and are commonly of the incomplete variety. They may easily be overlooked, and may even sometimes escape recognition until the reparative process has been well established and the wound is discovered owing to the prominence caused by the presence of the provisional callus which marks its cure. When the fracture is complete it will be marked by local deformity, mobility of the fragments, and crepitation. Nasal hemorrhage, roaring, frequent sneezing, loosening or loss of teeth, difficulty of mastication, and inflammation of the cavities of the sinuses are varying complications of these accidents. The object of the treatment should be the restoration of the depressed bones as nearly as possible to their normal position and their retention in place by protecting splints, which should cover the entire facial region. Special precautions should be observed to prevent the patient from disturbing the dressing by rubbing his head against surrounding objects, such as the stall, manger, rack, etc. Clots of blood in the nasal passages must be washed out, collections of pus removed from the sinuses, and, if the teeth are loosened and liable to fall out, they should be removed. If roaring is threatened, tracheotomy is indicated.

FRACTURES OF THE PREMAXILLARY BONE.

These are mentioned by continental authors and are usually encountered in connection with fractures of the nasal bone, and may take place either in the width or the length of the bone.

The deformity of the upper lip, which is drawn sidewise in this lesion, renders it easy of diagnosis. The abnormal mobility and the crepitation, with the pain manifested by the patient when undergoing examination, are concurrent symptoms. Looseness of the teeth, abundant salivation, and entire inability to grasp the feed complete the symptomatology of these accidents. In the treatment splints of gutta-percha or leather are sometimes used, but they are of difficult application. Our own judgment and practice are in favor of the union of the bones by means of metallic sutures.

FRACTURES OF THE LOWER JAW.

A fracture here is not an injury of infrequent occurrence. It involves the body of the bone, at its symphysis, or back of it, and includes one or both of its branches, either more or less forward, or at the posterior part near the temporomaxillary articulation, at the coronoid process.

Falls, blows, or other external violence, or powerful muscular contractions during the use of the speculum, may be mentioned among the causes of this lesion. The fracture of the neck, or that portion formed by the juncture of the two opposite sides, and of the branches in front of the cheeks, causes the lower jaw, the true dental arch, to drop, without the ability to raise it again to the upper, and the result is a peculiar and characteristic physiognomy. The prehension and mastication of feed become impossible; there is an abundant escape of fetid and sometimes bloody saliva, especially if the gums have been wounded; there is excessive mobility of the lower end of the jawbone; and there is crepitation, and frequently paralysis of the under lip. Although an animal suffering with a complete and often compound and comminuted fracture of the submaxilla presents at times a serious aspect, the prognosis of the case is comparatively favorable, and recovery is usually only a question of time. The severity of the lesion corresponds in degree to that of the violence to which it is due, also to the resulting complications and the situation of the wound. It is simple when at the symphysis, but becomes more serious when it affects one of the branches, and most aggravated when both are involved. Fracture of the coronoid process becomes important principally as an evidence of the existence of a morbid diathesis, such as osteoporosis, or the like.

The particular seat of the injury, with its special features, will, of course, determine the treatment. For a simple fracture, without displacement, provided there is no laceration of the periosteum, an ordinary supporting bandage will usually be sufficient, but when there is displacement the reduction of the fracture must first be accomplished, and for this special splints are necessary. In a fracture of the symphysis or of the branches the adjustment of the fragments by securing them with metallic sutures is the first step necessary, to be followed by the application of supports, consisting of splints of leather or sheets of metal, the entire front of the head being then covered with bandages prepared with adhesive mixtures. During the entire course of treatment a special method of feeding becomes necessary. The inability of the patient to appreciate the situation, of course, necessitates a resort to an artificial mode of introducing the necessary feed into his stomach; this is accomplished by forcing between the commissures of the lips, in a liquid form, by means of a syringe, the milk or nutritive gruels selected for his sustenance until the consolidation is sufficiently advanced to permit the ingestion of feed of a more solid consistency. The callus will usually be sufficiently hardened in two or three weeks to allow of a change of diet to mashes of cut hay and scalded grain, until the removal of the dressing restores the animal to its old habit of mastication.

FRACTURES OF VERTEBRAE.

These are not very common, but when they do occur the bones most frequently injured are those of the back and loins.

Causes.--The ordinary causes of fracture are responsible here as elsewhere, such as heavy blows on the spinal column, severe falls while conveying heavy loads, and especially violent efforts in resisting the process of casting. Although occurring more or less frequently under the latter circumstances, the accident is not always attributable to carelessness or error in the management. It may, of course, sometimes result from such a cause as a badly prepared bed, or the accidental presence of a hard body concealed in the straw, or to a heavy fall when the movements of the patient have not been sufficiently controlled by an effective apparatus and its skillful adaptation, but it is quite as liable to be caused by the violent resistance and the consequent powerful muscular contraction by the frightened patient. The simple fact of the overarching of the vertebral column, with excessive pressure against it from the intestinal mass, owing to the spasmodic action of the abdominal muscles, may account for it, and so also may the struggles of the animal to escape from the restraint of the hobbles while frantic under the pain of an operation without anesthesia. In these cases the fracture usually occurs in the body or the annular part, or both, of the posterior dorsal or the anterior lumbar vertebra. When the transverse processes of the last-named bones are injured, it is probably in consequence of the heavy concussion incident to striking the ground when cast. The diagnosis of a fracture of the body of a vertebra is not always easy, especially when quite recent, and more especially when there is no accompanying displacement.

Symptoms.--There are certain peculiar signs accompanying the occurrence of the accident while an operation is in progress which should at once excite the suspicion of the surgeon. In the midst of a violent struggle the patient becomes suddenly quiet; the movement of a sharp instrument, which at first excited his resistance, fails to give rise to any further evidence of sensation; perhaps a general trembling, lasting for a few minutes, will follow, succeeded by a cold, profuse perspiration, particularly between the hind legs, and frequently there will be micturition and defecation. Careful examination of the vertebral column may then detect a slight depression or irregularity in the direction of the spine, and there may be a diminution or loss of sensation in the posterior part of the trunk, while the anterior portion continues to be as sensitive as before. In making an attempt to get upon his feet, however, upon the removal of the hobbles, only the fore part of the body will respond to the effort, a degree of paraplegia being present, and while the head, neck, and fore part of the body will be raised, the hind quarters and hind legs will remain inert. The animal may perhaps succeed in rising and probably may be removed to his stall, but the displacement of the bone will follow, converting the fracture into one of the complete kind, either through the exertion of walking or by a renewed attempt to rise after another fall before reaching his stall. By this time the paralysis is complete, and the extension of the meningitis, which has become established, is a consummation soon reached.

To say that the prognosis of fracture of the body of the vertebra is always serious is to speak very mildly. It would be better, perhaps, to say that occasionally a case may recover. Fractures of the transverse processes are less serious.

Treatment.--Instead of stating the indication in this class of cases as if assuming them to be amenable to treatment, the question naturally would be: Can any treatment be recommended in a fracture of the body of a vertebra? The only indication in such a case, in our opinion, is to reach the true diagnosis in the shortest possible time and to act accordingly. If there is displacement, and the existence of serious lesions may be inferred from the nervous symptoms, the destruction of the suffering animal appears to suggest itself as the one conclusion in which considerations of policy, humanity, and science at once unite.

If, however, it is fairly evident that no displacement exists; that pressure upon the spinal cord is not yet present; that the animal with a little assistance is able to rise upon his feet and to walk a short distance--it may be well to experiment upon the case to the extent of placing the patient in the most favorable circumstances for recovery and allow nature to operate without further interference. This may be accomplished by obtaining immobility of the whole body as much as possible, and especially of the suspected region, by placing the patient in slings, in a stall sufficiently narrow to preclude lateral motion, and covering the loins with a thick coat of agglutinative mixture. Developments should be watched and awaited.

FRACTURE OF THE RIBS.

The different regions of the chest are not equally exposed to the violence that causes fractures of the ribs, and they are therefore either more common or more easily discovered during life at some points than at others. The more exposed regions are the middle and the posterior, while the front is largely covered and defended by the shoulder. A single rib may be the seat of fracture, or a number may be involved, and there may be injuries on both sides of the chest at the same time. It may take place lengthwise, in any part of the bone, though the middle, being the most exposed, is the most frequently hurt. Incomplete fractures are usually lengthwise, involving a portion only of the thickness of one or other of the surfaces. The complete kind may be either transverse or oblique, and are most commonly denticulated. The fracture may be comminuted, and a single bone may show one of the complete and one of the incomplete kind at different points. The extent of surface presented by the thoracic region, with its complete exposure at all points, explains the liability of the ribs to suffer from all the forms of external violence.

Symptoms.--In many instances fractures, especially the incomplete variety, of these bones continue undiscovered, without displacement, though the evidences of local pain, a certain amount of swelling, and a degree of disturbance of the respiration, if noticed during the examination of a patient, may suggest a suspicion of their existence. Abnormal mobility and crepitation are difficult of detection, even when present, and they are not always present. When there is displacement the deformity which it occasions will betray the fact, and when such an injury exists the surgeon, in view of possible and probable complications of thoracic trouble, of course will become vigilant and prepare himself for an encounter with a case of traumatic pleuritis or pneumonia. Fatal injuries of the heart are recorded. Subcutaneous emphysema is a common accompaniment of broken ribs, and I recall the death, from this cause, of a patient of my own which had suffered a fracture of two ribs in the region of the withers, under the cartilages of the shoulder, and of which the diagnosis was made only after the fatal ending of the case.

These hurts are not often of a very serious character, though the union is never so solid and complete as in other fractures, the callus being usually imperfect and of a fibrous character, with an amphiarthrosis formation. Still, complications occur which may impart gravity to the prognosis.

Treatment.--Fractures with but a slight or no displacement need no reduction. All that is necessary is a simple application of a blistering nature as a preventive of inflammation or for its subjugation when present, and in order to excite an exudation which will tend to aid in the support and immobilization of the parts. At times, however, a better effect is obtained by the application of a bandage placed firmly around the chest, although, while this limits the motion of the ribs, it is liable to render the respiration more labored.

If there is displacement, with much accompanying pain and evident irritation of the lungs, the fracture must be reduced without delay. The means of effecting this vary according to whether the displacement is outward or inward. In the first case the bone may be straightened by pressure from without, while in the second the end of it must be raised by a lever, for the introduction of which a small incision through the skin and intercostal spaces will be necessary. When coaptation has been effected it must be retained by the external application of an adhesive mixture, with splints and bandages around the chest.

FRACTURES OF THE BONES OF THE PELVIS.

These fractures will be considered under their separate denominations, as those of the sacrum and the os innominatum, or hip, which includes the subdivisions of the ilium, the pubes, and the ischium.

The sacrum.--Fractures of this bone are rarely met with among solipeds. Among cattle, however, it is of common occurrence, being attributed not only to the usual varieties of violence, as blows and other external hurts, but to the act of coition and violent efforts in parturition. It is generally of the transverse kind and may be recognized by the deformity which it occasions. This is due to the dropping of the bone, with a change in its direction and a lower attachment of the tail, which also becomes more or less paralyzed. The natural and spontaneous relief which usually interposes in these cases has doubtless been observed by the extensive cattle breeders of the West, and their practice and example fully establish the inutility of interference. Still, cases may occur in which reduction may be indicated, and it then becomes a matter of no difficulty. It is effected by the introduction of a round, smooth piece of wood into the rectum as far as the fragment of bone and using it as a lever, resting upon another as a fulcrum placed under it outside. The bone, having been thus returned, may be kept in place by the ordinary external means in use.

The os innominatum.--Fracture of the ilium may be observed either at the angle of the hip or at the neck of the bone; those of the pubes may take place at the symphysis, or in the body of the bone; those of the ischium on the floor of the bone, or at its posterior external angle. Or, again, the fracture may involve all three of these constituent parts of the hip bone by having its situation in the articular cavity--the acetabulum by which it joins the femur or thigh bone.

Symptoms.--Some of these fractures are easily recognized, while others are difficult to identify. The ordinary deformity which characterizes a fracture of the external angle of the ilium, its dropping and the diminution of that side of the hip in width, unite in indicating the existence of the condition expressed by the term "hipped." An incomplete fracture, however, or one that is complete without displacement, or even one with displacement, often demands the closest scrutiny for its discovery. The lameness may be well marked, and an animal may show it but little while walking, though upon being urged into a trot will manifest it more and more, until presently it will cease to use the crippled limb altogether, and travel entirely on three legs. The acute character of the lameness will vary in degree as the seat of the lesion approximates the acetabulum. In walking, the motion at the hip is very limited, and the leg is dragged; while at rest it is relieved from bearing its share in sustaining the body. An intelligent opinion and correct conclusion will depend largely upon a knowledge of the history of the case, and while in some instances that will be but a report of the common etiology of fractures, such as blows, hurts, and other external violence, the simple fact of a fall may furnish in a single word a satisfactory solution of the whole matter.

With the exception of the deformity of the ilium in a fracture of its external angle, and unless there has been a serious laceration of tissues and infiltration of blood, or excessive displacement, there are no very definite external symptoms in a case of a fracture of the hip bone. There is one, however, which, in a majority of cases, will not fail--it is crepitation. This evidence is attainable by both external and internal examination--by manipulation of the gluteal surface and by rectal taxis. Very often a lateral motion, or balancing of the hinder parts by pressing the body from one side to the other, will be sufficient to render the crepitation more distinct--a slight sensation of grating, which may be perceived even through the thick coating of muscle which covers the bone--and the sensation may not only be felt, but to the expert may even become audible. This external manifestation is, however, not always sufficient in itself, and should invariably be associated with the rectal taxis for corroboration. It is true that this may fail to add to the evidence of fracture, but till then the simple testimony afforded by the detection of crepitation from the surface, though a strong confirmatory point, is scarcely sufficiently absolute to establish more than a reasonable probability or strong suspicion in the case.

In addition to the fact that the rectal examination brings the exploring hand of the surgeon into near proximity to the desired point of search, and to an accurate knowledge of the situation of parts, both pro and con as respects his own views, there is another advantage attendant upon it which is well entitled to appreciation. This is the facility with which he can avail himself of the help of an assistant, who can aid him by manipulating the implicated limb and placing it in various positions, so far as the patient will permit, while the surgeon himself is making explorations and studying the effect from within. By this method he can hardly fail to ascertain the character of the fracture and the condition of the bony ends. By the rectal taxis, as if with eyes in the finger ends, he will "see" what is the extent of the fracture of the ilium or of the neck of that bone; to what part of the central portion of the bone (the acetabulum) it reaches; whether this is free from disease or not, and in what location on the floor of the pelvis the lesion is situated. By this method we have frequently been able to detect a fracture at the symphysis, which, from its history and symptoms and an external examination, could only have been guessed at. Yet, with all its advantages, the rectal examination is not always necessary, as, for example, when the fracture is at the posterior and external angle of the ischium, when by friction of the bony ends the surgeon may discern the crepitation without it.

Every variety of complication, including muscular lacerations with the formation of deep abscesses and injuries to the organs of the pelvic cavity, the bladder, the rectum, and the uterus, may be associated with fractures of the hip bone.

Prognosis.--The prognosis of these lesions will necessarily vary considerably. A fracture of the most superficial part of the bone of the ilium or of the ischium, especially if there is little displacement, will unite rapidly, leaving a comparatively sound animal often quite free from subsequent lameness. If there is much displacement, however, only a ligamentous union will take place, with much deformity and more or less irregularity in the gait. Other fractures may be followed by complete disability of the patient, as, for example, when the cotyloid cavity is involved, or when the reparatory process has left bony deposits in the pelvic cavity at the seat of the union, which may, in the case of the female, interfere with the steps of parturition, or induce some local paralysis by pressure upon the nerves which govern the muscles of the hind legs. This is a condition not infrequently observed when the callus has been formed on the floor of the pelvis near the obturator foramen, pressing upon the course or involving the obturator nerve.

Treatment.--In our estimation, the treatment of all fractures of the hip bone should be of the simplest kind. Rendered comparatively immovable by the thickness of the muscles by which the region is enveloped, one essential indication suggests itself, and that is to place the animal in a position which, so far as possible, will be fixed and permanent. For the accomplishment of this purpose the best measure, as we consider it, is to place the horse in a stall of just sufficient width to admit him, and to apply a set of slings, snugly, but comfortably. (See Plate XXXI.) This will fulfill the essential conditions of recovery--rest and immobility. Blistering applications would be injurious, though the adhesive mixture might prove in some degree beneficial.

The minimum period allowable for solid union in a fractured hip is, in our judgment, two months, and we have known cases in which that was too short a time.

As we have said before, there may be cases in which the treatment for fracture at the floor of the pelvis has been followed by symptoms of partial paralysis, the animal, when lying down, being unable to regain his feet, but moving freely when placed in an upright position. This condition is owing to the interference of the callus with the functions of the obturator nerve, which it presses upon or surrounds. By my experience in similar cases I feel warranted in cautioning owners of horses in this condition to exercise due patience, and to avoid a premature sentence of condemnation against their invalid servants; they are not all irrecoverably paralytic. With alternations of moderate exercise, rest in the slings, and the effect of time while the natural process of absorption is taking effect upon the callus, with other elements of change that may be so operating, the horse in due time may become able once more to earn his subsistence and serve his master.

FRACTURE OF THE SCAPULA.

This bone is seldom fractured, its comparative exemption being due to its free mobility and the protection it receives from the superimposed soft tissues. Only direct and powerful causes are sufficient to effect the injury, and when it occurs the large rather than the smaller animals are the subjects.

Cause.--The causes are heavy blows or kicks and violent collisions with unyielding objects. Those which are occasioned by falls are generally at the neck of the bone, and of the transverse and comminuted varieties.

Symptoms.--The diagnosis is not always easy. The symptoms are inability to rest the leg on the ground and to carry weights, and they are present in various degrees from slight to severe. The leg rests upon the toe, seems shortened, and locomotion is performed by jumps. Moving the leg while examining it and raising the foot for inspection seem to produce much pain and cause the animal to rear. Crepitation is readily felt with the hand upon the shoulder when the leg is moved. If the fracture occurs in the upper part of the bone, overlapping of the fragments and displacement will be considerable.

The fracture of this bone is usually classed among the more serious accidents, though cases may occur which are followed by recovery without very serious ultimate results, especially when the seat of the injury is at some of the upper angles of the bone or about the acromion crest. But if the neck and the joint are the parts involved, complications which are likely to disable the animal for life are liable to be present.

Treatment.--If there is no displacement, a simple adhesive dressing to strengthen and immobilize the parts will be sufficient. A coat of black pitch dissolved with wax and Venice turpentine, and kept in place over the region with oakum or linen bands, will be all the treatment required, especially if the animal is kept quiet in the slings.

Displacement can not be remedied, and reduction is next to impossible. Sometimes an iron plate is applied over the parts and retained by bandages, as in the dressing of Bourgelat (Plate XXX); this may be advantageously replaced by a pad of thick leather. In smaller animals the parts are retained by figure-8 bandages, embracing both the normal and the diseased shoulders, crossing each other in the axilla and covered with a coating of adhesive mixture.

FRACTURES OF THE HUMERUS.

These are more common in small than in large animals, and are always the result of external traumatism, such as falls, kicks, and collisions. They are generally very oblique, are often comminuted, and though more usually involving the shaft of the bone will in some cases extend to the upper end and into the articular head.

Symptoms.--There is ordinarily considerable displacement in consequence of the overlapping of the broken ends of the bone, and this of course causes more or less shortening of the limb. There will also be swelling, with difficulty of locomotion, and crepitation will be easy of detection. This fracture is always a serious damage to the patient, leaving him with a permanently shortened limb and an incurable, lifelong lameness.

Treatment.--If treatment is determined on, it will consist in the reduction of the fracture by means of extension and counter extension, to accomplish which the animal must be thrown. If successful in the reduction, then follows the application and adjustment of the apparatus of retention, which must be of the most perfect and efficient kind. Finally, this, however skillfully contrived and carefully adapted, will often fail to effect any good purpose whatever.

FRACTURES OF THE FOREARM.

A fracture in this region may also involve the radius or the ulna, the latter being broken at times in its upper portion above the radio-ulnar arch at the olecranon. If the fracture occurs at any part of the forearm from the radio-ulnar arch down to the knee, it may involve either the radius alone or the radius and the cubitus, which are there intimately united.

Cause.--Besides having the same etiology with most of the fractures, those of the forearm are, nevertheless, more commonly due to kicks from other animals, especially when crowded together in large numbers in insufficient space. It is a matter of observation that under these circumstances fractures of the incomplete kind are those which occur on the inside of the leg, the bone being in that region almost entirely subcutaneous, while those of the complete class are either oblique or transverse. The least common are the longitudinal, in the long axis of the bone.

Symptoms.--This variety of fracture is easily recognized by the appearance of the leg and the different changes it undergoes. There is inability to use the limb; impossibility of locomotion; mobility below the injury; the ready detection of crepitation--in a word, the assemblage of all the signs and symptoms which have been already considered as associated with the history of broken bones.

The fracture of the ulna alone, principally above the radio-ulnar arch, may be ascertained by the aggravated lameness, the excessive soreness on pressure, and perhaps a certain increase of motion, with a very slight crepitation if tested in the usual way. Displacement is not likely to take place except when it is well up toward the olecranon or its tuberosity, the upper segment of the bone being in that case likely to be drawn upward. For a simple fracture of this region there is a fair chance of recovery, but in a case of the compound and comminuted class there is less ground for a favorable prognosis, especially if the elbow joint has suffered injury. A fracture of the ulna alone is not of serious importance, except when the same conditions prevail. A fracture of the olecranon is less amenable to treatment, and promises little better than a ligamentous union.

Treatment.--Considering all the various conditions involving the nature and extent of these lesions, the position and direction of the bones of the forearm are such as to render the chances for recovery from fracture as among the best. The reduction, by extension and counterextension; the maintenance of the coaptation of the segments; the adaptation of the dressing by splints, oakum, and agglutinative mixtures; in fact, all the details of treatment may be here fulfilled with a degree of facility and precision not attainable in any other part of the organism. An important, if not an essential, point, however, must be emphasized in regard to the splints. Whether they are of metal, wood, or other material, they should reach from the elbow joint to the ground, and should be placed on the posterior face and on both sides of the leg. This is then to be so confined in a properly constructed box as to preclude all possibility of motion, while yet it must sustain a certain portion of the weight of the body. The iron splint (represented in Plate XXX) recommended by Bourgelat is designed for fractures of the forearm, of the knee, and of the cannon bone, and will prove to be an appliance of great value. For small animals the preference is for an external covering of gutta-percha, embracing the entire leg. A sheet of this substance of suitable thickness, according to the size of the animal, softened in lukewarm water, is, when sufficiently pliable, molded on the outside of the leg, and when suddenly hardened by the application of cold water forms a complete casing sufficiently rigid to resist all motion. Patients treated in this manner have been able to use the limb freely, without pain, immediately after the application of the dressing. The removal of the splint is easily effected by cutting it away, either wholly or in sections, after softening it by immersing the leg in a warm bath.

FRACTURE OF THE KNEE.

This accident, happily, is of rare occurrence, but when it takes place is of a severe character, and always accompanied with synovitis, with disease of the joint.

Cause.--It may be caused by falling upon a hard surface, and is usually compound and comminuted. Healing seldom occurs, and when it does there is usually a stiffness of the joint from arthritis.

Symptoms.--As a result of this fracture there is inability to bear weight on the foot. The leg is flexed as in complete radial paralysis, or fracture of the ulna. There is abnormal mobility of the bones of the knee, but crepitation is usually absent.

Prognosis.--Healing is hard to effect, as one part of the knee is drawn upward by the two flexor muscles which separate it from the lower part. The callus which forms is largely fibrous, and if the animal is put to work too quickly this callus is liable to rupture. In favorable cases healing takes place in two or three months. Many horses during the treatment develop founder, with consequent drop sole in the sound leg, as a result of pressure due to continuous standing.

Treatment.--Place the animal in the slings, bring the pieces of bone together if possible, and try to keep them in place by a tight plaster-of-Paris dressing about the leg, extending down to the fetlock. Place the animal in a roomy box stall well provided with bedding so that he can lie down, to prevent founder.

FRACTURE OF THE FEMUR.

The protection which this bone receives from the large mass of muscles in which it is enveloped does not suffice to invest it with immunity in regard to fractures.

Cause.--It contributes its share to the list of accidents of this description, sometimes in consequence of external violence and sometimes as the result of muscular contraction; sometimes it takes place at the upper extremity of the bone; sometimes at the lower; sometimes at the head, when the condyles become implicated; but it is principally found in the body or diaphysis. The fracture may be of any of the ordinary forms, simple or compound, complete or incomplete, transverse or oblique, etc. A case of the comminuted variety is recorded in which 85 fragments of bone were counted and removed.

The thickness of the muscular covering sometimes renders the diagnosis difficult by interfering with the manipulation, but the crepitation test is readily available, even when the swelling is considerable, and which is liable to be the case as the result of the interstitial hemorrhage which naturally follows the laceration of the blood vessels of the region involved.

Symptoms.--If the fracture is at the neck of the bone the muscles of that region (the gluteal) are firmly contracted, and the leg seems to be shortened in consequence. Locomotion is impossible. There is intense pain and violent sweating at first. Crepitation may in some cases be discerned by rectal examination, with one hand resting over the coxo-femoral (hip) articulation. Fractures of the tuberosities of the upper end of the bone, the great trochanter, may be identified by the deformity, the swelling, the impossibility of rotation, and the dragging of the leg in walking. Fracture of the body is always accompanied with displacement, and as a consequence a shortening of the leg, which is carried forward. The lameness is excessive, the foot being moved, both when raising it from the ground and when setting it down, very timidly and cautiously. The manipulations for the discovery of crepitation always cause much pain. Lesions of the lower end of the bone are more difficult to diagnosticate with certainty, though the manifestation of pain while making heavy pressure upon the condyles will be so marked that only crepitation will be needed to turn a suspicion into a certainty.

Treatment.--The question as to treatment in fractures of this description resolves itself into the query whether any treatment can be suggested that will avail anything practically as a curative measure; whether, upon the hypothesis of reduction as an accomplished fact, any permanent or efficient device as a means of retention is within the scope of human ingenuity. If the reduction were successfully performed, would it be possible to keep the parts in place by any known means at our disposal? At the best the most favorable result that could be anticipated would be a reunion of the fragments with a considerable shortening of the bone and a helpless, limping, crippled animal to remind us that for human achievement there is a "thus far and no farther."

In small animals, such as dogs and cats, however, attempts at treatment are justifiable, and we are convinced that in many cases of difficulty in the application of splints and bandages a patient may be placed in a condition of undisturbed quiet and left to the processes of nature for "treatment" as safely and with as good an assurance of a favorable result as if he had been subjected to the most heroic secundum artem doctoring known to science. As a case in point, mention may be made of the case of a pregnant bitch which suffered a fracture of the upper end of the femur by being run over by a light wagon. Her "treatment" consisted in being tied up in a large box and let alone. In due time she was delivered of a family of puppies, and in three weeks she was running in the streets, limping very slightly, and nothing the worse for her accident.

FRACTURE OF THE PATELLA.

This, fortunately, is a rare accident, and can result only from direct violence, as a kick or other blow. The lameness which follows it is accompanied with enormous tumefaction of the joint, pain, inability to bear weight upon the foot, and finally disease of the articulation. Crepitation is absent, because the hip muscles draw away the upper part of the bone. The prognosis is unavoidably adverse, destruction being the only termination of this incurable and very painful injury. Most of the reported cases of cures are based upon a wrong diagnosis.

FRACTURES OF THE TIBIA.

Of all fractures these are probably more frequently encountered than any others among the class of accidents we are considering. As with injuries of the forearm of a like character, they may be complete or incomplete; the former when the bone is broken in the middle or at the extremities, and transverse, oblique, or longitudinal. The incomplete kind are more common in this bone than in any other.

Symptoms.--Complete fractures are easy to recognize, either with or without displacement. The animal is very lame, and the leg is either dragged or held clear from the ground by flexion at the stifle, while the lower part hangs down. Carrying weight or moving backward is impossible. There is excessive mobility below the fracture, and well-marked crepitation. If there is much displacement, as in an oblique fracture, there will be considerable shortening of the leg.

While incomplete fractures can not be recognized in the tibia with any greater degree of certainty than in any other bone, there are some facts associated with them by which a diagnosis may be justified. The hypothetical history of a case may serve as an illustration:

An animal has received an injury by a blow or a kick on the inside of the bone, perhaps without showing any mark. Becoming very lame immediately afterwards, he is allowed a few days' rest. If taken out again, he seems to have recovered his soundness, but within a day or two he betrays a little soreness, and this increasing he becomes very lame again, to be furloughed once more, with the result of a temporary improvement, and again a return to labor and again a relapse of the lameness; and this alternation seems to be the rule. The leg being now carefully examined, a local periostitis is readily discovered at the point of the injury, the part being warm, swollen, and painful. What further proof is necessary? Is it not evident that a fracture has occurred, first superficial--a mere split in the bony structure, which, fortunately, has been discovered before some extra exertion or a casual misstep had developed it into one of the complete kind, possibly with complications? What other inference can such a series of symptoms thus repeated establish?

The prognosis of fracture of the tibia, as a rule, must be unfavorable.

Treatment.--The difficulty of obtaining a union without shortening, and consequently without lameness, is proof of the futility of ordinary attempts at treatment, but though this may be true in respect to fractures of the complete kind, it is not necessarily so with the incomplete variety, and with this class the simple treatment of the slings is all that is necessary to obtain consolidation. A few weeks of this confinement will be sufficient.

With dogs and other small animals there are cases which may be successfully treated. If the necessary dressings can be successfully applied and retained, a cure will follow.

FRACTURES OF THE HOCK.

Injuries of the astragalus which had a fatal termination have been recorded. Fractures of the os calcis have also been observed, but never with a favorable prognosis, and attempts to induce recovery, as might have been expected, have proved futile.

FRACTURES OF THE CANNON BONES.

Whether these occur in the fore or hind legs, they appear either in the body or near their extremities. If in the body as a rule the three metacarpal or metatarsal bones are affected, and the fracture is generally transverse and oblique. On account of the absence of soft tissue and tightness of the skin, the broken bones pierce the skin and render the fracture a complicated one. The diagnosis is easy when all the bones are completely broken, but the incomplete fracture can be only suspected.

Symptoms.--There is no displacement, but excessive mobility, crepitation, inability to sustain weight, and the leg is kept off the ground by the flexion of the upper joint.

No region of the body affords better facilities for the application of treatment, and the prognosis on this account is usually favorable. We recall a case, however, which proved fatal, though under exceptional circumstances. The patient was a valuable stallion of highly nervous organization, with a compound fracture of one of the cannon bones, and his unconquerable resistance to treatment, excited by the intense pain of the wound, precluded all chance of recovery, and ultimately caused his death.

Treatment.--The general form of treatment for these lesions will not differ from that which has been already indicated for other fractures. Reduction, sometimes necessitating the casting of the patient; coaptation, comparatively easy by reason of the subcutaneous situation of the bone; retention, by means of splints and bandages--applied on both sides of the region, and reaching to the ground as in fractures of the forearm--these are always indicated. We have obtained excellent results by the use of a mold of thick gutta-percha, composed of two sections and made to surround the entire lower part of the leg as in an inflexible case.

FRACTURE OF THE FIRST PHALANX.

The hind extremity is more liable than the fore to this injury. It is usually the result of a violent effort, or of a sudden misstep or twisting of the leg, and may be transverse, or, as has usually been the case in our experience, longitudinal, extending from the upper articular surface down to the center of the bone, and generally oblique and often comminuted. The symptoms are the swelling and tenderness of the region, possibly crepitation; a certain abnormal mobility; an excessive degree of lameness, and in some instances a dropping back of the fetlock, with perhaps a straightened or upright condition of the pastern.

The difficulty of reduction and coaptation in this accident, and the probability of bony deposits, as of ringbones, resulting in lameness, are circumstances which tend to discourage a favorable prognosis.

The treatment is that which has been recommended for all fractures, so far as it can be applied. The iron splint which has been mentioned gives excellent results in many instances, but if the fracture is incomplete and without displacement, a form of treatment less energetic and severe should be attempted. One case is within our knowledge in which the owner lost his horse by his refusal to subject the animal to treatment, the post-mortem revealing only a simple fracture with very slight displacement.

FRACTURES OF THE SECOND PHALANX (CORONET).

Though these are generally of the comminuted kind, there are often conditions associated with them which justify the surgeon in attempting their treatment. Though crepitation is not always easy to detect, the excessive lameness, the soreness on pressure, the inability to carry weight, the difficulty experienced in raising the foot, all these suggest, as the solution of the question of diagnosis, the fracture of the coronet, with the accompanying realization of the fact that there is yet, by reason of the situation of the member, immobilized as it is by its structure and its surroundings, room left for a not unfavorable prognosis. Only a slight manipulation will be needed in the treatment of this lesion. To render the immobility of the region more fixed, to support the bones in their position by bandaging, and to establish forced immobility of the entire body with the slings is usually all that is required. Ringbone, being a common sequela of the reparative process, must receive due attention subsequently. One of the severest complications liable to be encountered is an immobile joint (anchylosis). Neurectomy of the median nerve may relieve lameness after a fracture of the phalanges.

FRACTURES OF THE THIRD PHALANX (OS PEDIS).

These lesions may result from a penetrating street nail, or follow plantar or median neurectomy. In the latter instance it is caused by the animal setting the foot down carelessly and too violently, and partly due to degeneration of bone tissue which follows nerving.

Though these fractures are not of very rare occurrence, their recognition is not easy, and there is more of speculation than of certainty pertaining to their diagnosis. The animal is very lame and spares the injured foot as much as possible, sometimes resting it upon the toe alone and sometimes holding it from the ground. The foot is very tender, and the exploring pinchers of the examining surgeon cause much pain. During the first 24 hours there is no increased pulsation in the digital and plantar arteries, but on the second day it is apparent.

There is nothing to encourage a favorable prognosis, and a not unusual termination is an anchylosis with either the navicular bone or the coronet.

No method of treatment needs to be suggested here, the hoof performing the office of retention unaided. Local treatment by baths and fomentations will do the rest. It may be months before there is any mitigation of the lameness.

An ultimate recovery depends to a great extent upon whether the other foot can support the weight during the healing process without causing a drop sole in the supporting foot.

FRACTURE OF THE SESAMOID BONES.

This lesion has been considered by veterinarians, erroneously, we think, as one of rare occurrence. We believe it to be more frequent than has been supposed. Many observations and careful dissections have convinced us that fractures of these little bones have been often mistaken for specific lesions of the numerous ligaments that are implanted upon their superior and inferior parts, and which have been described as a "giving way" or "breaking down" of these ligaments. In my post-mortem examinations I have always noted the fact that when the attachments of the ligaments were torn from their bony connections minute fragments of bony structure were also separated, though we have failed to detect any diseased process of the fibrous tissue composing the ligamentous substance.

Cause.--From whatever cause this lesion may arise, it can hardly be considered as of a traumatic nature, no external violence having any apparent agency in producing it, and it is our belief that it is due to a peculiar degeneration or softening of the bones themselves, a theory which acquires plausibility from the consideration of the spongy consistency of the sesamoids. The disease is a peculiar one, and the suddenness with which different feet are successively attacked, at short intervals and without any obvious cause, seems to prove the existence of some latent, morbid cause which has been unsuspectedly incubating. It is not peculiar to any particular class of horses, nor to any special season of the year, having fallen under our observation in each of the four seasons.

Symptoms.--The general fact is reported in the history of most cases that it makes its appearance without premonition in animals which, after enjoying a considerable period of rest, are first exercised or put to work, though in point of fact it may manifest itself while the horse is still idle in his stable. A hypothetical case, in illustration, will explain our theory: An animal which has been at rest in his stable is taken out to work, and it will be presently noticed that there is something unusual in his movement. His gait is changed, and he travels with short, mincing steps, without any of his accustomed ease and freedom. This may continue until his return to the stable, and then, after being placed in his stall, he will be noticed shifting his weight from side to side and from one leg to another, continuing the movement until rupture of the bony structure takes place. But it may happen that the lameness in one or more of the extremities, anterior or posterior, suddenly increases, and it becomes evident that the rupture has taken place in consequence of a misstep or a stumble while the horse is at work. Then, upon coming to a standstill, he will be found with one or more of his toes turned up; he is unable to place the affected foot flat on the ground. The fetlock has dropped and the leg rests upon this part, the skin of which may have remained intact or may have been more or less extensively lacerated. It seldom happens that more than one toe at a time will turn up, yet still the lesion in one will be followed by its occurrence in another. Commonly two feet, either the anterior or posterior, are affected, and we recall one case in which the two fore and one of the hind legs were included at the same time. The accident, however, is quite as liable to happen while the horse is at rest in his stall, and he may be found in the morning standing on his fetlocks. One of the earliest of the cases occurring in my own experience had been under care for several weeks for suspected disease of the fetlocks, the nature of which had not been made out, when, apparently improved by the treatment which he had undergone, the patient was taken out of the stable to be walked a short distance into the country, but had little more than started when he was called to a halt by the fracture of the sesamoids of both fore legs.

While there are no positive premonitory symptoms of these fractures known, we believe that there are signs and symptoms which come but little short of being so, and the appearance of which will always justify a strong suspicion of the truth of the case. These have been indicated when referring to the soreness in standing, the short, mincing gait, and the tenderness betrayed when pressure is made over the sesamoids on the sides of the fetlock, with others less tangible and definable.

Prognosis.--These injuries can never be accounted less than serious, and in our judgment will never be other than fatal. If our theory of their pathology is the correct one, and the cause of the lesions is truly the softening of the sesamoidal bony structure and independent of any changes in the ligamentous fibers, the possibility of a solid osseous union can hardly be considered admissible.

Treatment.--In respect to the treatment to be recommended and instituted it can be employed only with any rational hope of benefit during the incubation, and with the anticipatory purpose of prevention. It must be suggested by a suspicion of the verities of the case, and applied before any rupture has taken place. To prevent this and to antagonize the causes which might precipitate the final catastrophe--the elevation of the toes--resort must be had to the slings and to the application of firm bandages or splints, perhaps of plaster of Paris, with a high shoe, as about the only indications which science and nature are able to offer. When the fracture is an occurred event, and the toes, one or more, are turned up, any further resort to treatment will be futile.

DISEASES OF JOINTS.

Three classes of injury will be considered under this head. These are, affections of the synovial sacs, those of the joint structures, or of the bones and their articular surfaces, and those forms of solution of continuity known as dislocations or luxations.

DISEASES OF THE SYNOVIAL SACS.

Two forms of affection here present themselves, one being the result of an abnormal secretion which induces a dropsical condition of the sac without any acute, inflammatory action, while the other is characterized by excessive inflammatory symptoms, with their modifications, constituting synovitis.

SYNOVIAL DROPSIES.

We have already considered in a general way the presence of these peculiar oil bags in the joints, and in some regions of the legs where the passage of the tendons takes place, and have noticed the similarity of structure and function of both the articular and the tendinous bursae, as well as the etiology of their injuries and their pathological history, and we will now treat of the affections of both.

WINDGALLS.

This name is given to the dilated bursae found at the posterior part of the fetlock joint. They have their origin in a dropsical condition of the bursae of the joint itself, also of the tendon which slides behind it, and are therefore further known by the designations of articular and tendinous windgalls, or puffs. (See also p. 401.)

They appear in the form of soft and somewhat symmetrical tumors, of varying dimensions, and generally well defined in their circumference. They are more or less tense, according to the quantity of secretion they contain, apparently becoming softer as the foot is raised and the fetlock flexed. Usually they are painless and only cause lameness under certain conditions, as when they begin to develop themselves under the stimulus of inflammatory action, or when large enough to interfere with the functions of the tendons, or again when they have undergone certain pathological changes, such as calcification, which is among their tendencies.

Cause.--Windgalls may be attributed to external causes, such as severe labor or strains resulting from heavy pulling, fast driving, or jumping, or they may be among the sequelae of internal disorders, such as strangles or the resultants of a pleuritic or pneumonic attack.

Unnecessary anxiety is sometimes experienced respecting these growths, with much questioning touching the expediency of their removal, all of which might be spared, for, while they constitute a blemish, their unsightliness will not hinder the usefulness of the animal, and in any case they rarely fail to show themselves easily amenable to treatment.

Treatment.--When in their acute stage, and when the dropsical condition is not excessive, the inflammation may be checked during the day by continuous, cold-water irrigation by means of a hose or soaking tub and at night by applying a moderately tight-roller bandage. Later absorption may be promoted by a Priessnitz bandage,[2] pressure by roller bandages, sweating, the use of liniments, or if necessary by a sharp blister of biniodid of mercury. This treatment should subdue the inflammation, abate the soreness, absorb the excess of secretion, strengthen the walls of the sac, and finally cause the windgalls to disappear, provided the animal is not too quickly returned to labor and exposed to the same factors that occasioned them at first.

If the inflammation has become chronic, however, and the enlargement has been of considerable duration, the negative course will be the wiser one. If any benefit results from treatment it will be of only a transient kind, the dilatation returning when the patient is again subjected to labor, and it will be a fortunate circumstance if inflammation has not supervened.

Notwithstanding the generally benignant nature of the swelling there are exceptional cases, usually when it is probably undergoing certain pathological changes, which may result in lameness and disable the animal, in which case surgical treatment will be indicated, especially if repeated blisters have failed to improve the symptoms. Line firing is then a preeminent suggestion, and many a useful life has received a new lease as the result of this operation timely performed. Another method of firing, which consists in emptying the sac by means of punctures through and through, made with a red-hot needle or wire, and the subsequent injection of certain irritating and alterative compounds into the cavity, designed to effect its closure by exciting adhesive inflammation, such as tincture of iodin, may be commended. But they are all too active and energetic in their effects and require too much special attention and intelligent management to be trusted to any hands other than those of an expert veterinarian.

BLOOD SPAVIN, BOG SPAVIN, AND THOROUGHPIN.

The blood spavin is situated in front and to the inside of the hock and is merely a varicose or dilated condition of the saphena vein. It occurs directly over the point where the bog spavin is found, and has thus been frequently confused with the latter.

The complicated arrangement of the hock joint, and the powerful tendons which pass on the posterior part, are lubricated with the product of secretion from one tendinous synovial and several articular synovial sacs. A large articular sac contributes to the lubrication of the shank bone (the tibia) and one of the bones of the hock (the astragalus). The tendinous sac lies back of the articulation itself and extends upward and downward in the groove of that joint through which the flexor tendons slide. The dilatation of this articular synovial sac is what is denominated bog spavin, the term thoroughpin being applied to the dilatation of the tendinous capsule.

The bog spavin is a round, smooth, well-defined, fluctuating tumor situated in front and a little inward of the hock. On pressure it disappears at this point to reappear on the outside and just behind the hock. If pressed to the front from the outside it will then appear on the inside of the hock. On its outer surface it presents a vein which is quite prominent, running from below upward, and it is to the preternatural dilatation of this blood vessel that the term blood spavin is applied.

The thoroughpin is found at the back and on the top of the hock in that part known as the "hollows," immediately behind the shank bone. It is round and smooth, but not so regularly formed as the bog spavin, and is most apparent when viewed from behind. The swelling is usually on both sides and a little in front of the so-called hamstring, but may be more noticeable on the inside or on the outside.

In their general characteristics bog spavins and thoroughpins are similar to windgalls, and one description of the origin, symptoms, pathological changes, and treatment will serve for all equally, except that it is possible for a bog spavin to cause lameness, and thus to involve a verdict of unsoundness in the patient, a circumstance which will, of course, justify its classification by itself as a severer form of a single type of disease.

We have already referred to the subject of treatment and the means employed--rest, of course--with liniments, blisters, etc., and what we esteem as the most active and beneficial of any, early, deep, and well-performed cauterization. There are, besides, commendatory reports of a form of treatment by the application of pressure pads and peculiar bandages upon the hocks, and it is asserted that the removal of the tumors has been effected by their use. Our experience with this apparatus, however, has not been accompanied with such favorable results as would justify our indorsement of the flattering representations which have sometimes appeared in its behalf.

OPEN JOINTS, BROKEN KNEES, SYNOVITIS, AND ARTHRITIS.

The close relationship which exists among these several affections, their apparently possible connection as successive developments of a similar, if not an essentially identical, origin, together with the advantage gained by avoiding frequent repetitions in the details of symptoms, treatment, etc., are our reasons for treating under a single head the ailments we have grouped together in the present section.

Cause.--The great, comprehensive, common cause of, sometimes permanent, sometimes only transient, disability of the horse is external traumatism.

Blows, bruises, hurts by nearly every known form of violence, falls, kicks, lacerations, punctures--we may add compulsory speed in racing and cruel overloading of draft animals--cover the entire ground of causation of the diseases and injuries of the joints now receiving our consideration.

In one case, a working horse making a misstep stumbles, and falling on his knees receives a hurt, variously severe, from a mere abrasion of the skin to a laceration, a division of the tegument, a slough, mortification, and the escape of the synovial fluid, with or without exposure of the bones and their articular cartilages.

In another case, an animal, from one cause or another, perhaps an impatient temper, has formed the habit of striking or pawing his manger with his fore feet until inflammation of the knee joint is induced, first as a little swelling, diffused, painless; then as a periostitis of the bones of the knee; later as bony deposits, then lameness, and finally the implication of the joint, with all the various sequelae of chronic inflammation of the knee joint.

In another case, a horse has received a blow with a fork from a careless hostler on or near a joint, or has been kicked by a stable companion, with the result of a punctured wound, at first mild-looking, painless, apparently without inflammation, and not yet causing lameness, but which, in a few hours, or it may be only after a few days, becomes excessively painful, grows worse, the entire joint swells, presently discharges, and at last a case of suppurative synovitis is presented, with perhaps disease of the joint proper, and arthritis as a climax. The symptoms of articular injuries vary not only in the degrees of the hurt but in the nature of the lesion.

Or the condition of broken knees, resulting as we have said, may have for its starting point a mere abrasion of the skin--a scratch, apparently, which disappears without a scar. The injury may, however, have been more severe, the blow heavier, the fall aggravated by occurring upon an irregular surface, or sharp or rough object, with tearing or cutting of the skin, and this laceration may remain. A more serious case than the first is now brought to our notice.

Another time, immediately following the accident, or possibly as a sequel of the traumatism, the tendinous sacs may be opened, with the escape of the synovia, or, worse, the tendons which pass in front of the knee are torn, the inflammation spreads, the joint and leg are swollen, the animal is becoming very lame; synovitis has set in. With this the danger becomes very great, for soon suppuration will be established, then the external coat of the articulation proper becomes ulcerated, if it is not already in that state, and we find ourselves in the presence of an open joint with suppurative synovitis--that is, with the worst among the conditions of diseased processes, because of the liability of the suppuration to become infiltrated into every part of the joint, macerating the ligaments and irritating the cartilages, soon to be succeeded by their ulceration, with the destruction of the articular surface--or the lesion of ulcerative arthritis, one of the gravest among all the disorders known to the animal economy.

Ulcerative arthritis and suppurative synovitis may be developed otherwise than in connection with open joints; the simplest and apparently most harmless punctures may prove to be sufficient cause. For example, a horse may be kicked, perhaps, on the inside of the hock; there is a mark and a few drops of blood to indicate the spot; he is put to work apparently free from pain or lameness and performs his task with his usual ease and facility. On the following morning, however, the hock is found to be a little swollen and there is some stiffness. A little later on he betrays a degree of uneasiness in the leg, and shrinks from resting his weight upon it, moving it up and down for relief. The swelling has increased and is increasing; the pain is severe; and finally, at the spot where the kick inpinged, there is an oozing of an oily liquid mixed with whitish drops of suppuration. The mischief is done; a simple, harmless, punctured wound has expanded into a case of ulcerative arthritis and suppurative synovitis.

Prognosis.--From ever so brief and succinct description of this traumatism of the articulations, the serious and important character of these lesions, irrespective of which particular joint is affected, will be readily understood. Yet there will be modifications in the prognosis in different cases, in accordance with the peculiarities of structure in the joint specially involved, as, for example, it is obvious that a better result may be expected from treatment when but a single joint, with only its plain articular surfaces, is the place of injury, than in one which is composed of several bones, united in a complex formation, as in the knee or hock. As severe a lesion as suppurative synovitis always is, and as frequently fatal as it proves to be, still cases arise in which, the inflammation assuming a modified character and at length subsiding, the lesion terminates favorably and leaves the animal with a comparatively sound and useful joint. There are cases, however, which terminate in no more favorable a result than the union of the bones and occlusion of the joint, to form an anchylosis, which is scarcely a condition to justify a high degree of satisfaction, as it insures a permanent lameness with very little capacity for usefulness.

Appreciating now the dangers associated with all wounds of articulations, however simple and apparently slight, and how serious and troublesome are the complications which are liable to arise during their progress and treatment, we are prepared to understand and realize the necessity and the value of early and prompt attention upon their discovery and diagnosis.

Treatment.--For simple bruises, like those which appear in the form of broken knees or of carpitis, simple remedies, such as warm fomentations or cold-water applications and compresses of astringent mixtures, suggest themselves at once. Injuries of a more complicated character, as lacerations of the skin or tearing of soft structures, will also be benefited by simple dressings with antiseptic mixtures, as those of the carbolic-acid order. The escape of synovia should suggest the prompt use of collodion dressings to check the flow and prevent the further escape of the fluid. But if the discharge is abundant and heavily suppurative, little can be done more than to put in practice the "expectant" method with warm fomentations, repeatedly applied, and soothing, mucilaginous poultices. Improvement, if any is possible, will be but slow to manifest itself. The most difficult of all things to do, in view of varying interests and opinions--that is, in a practical sense--is to abstain from "doing" entirely, and yet in the cases we are considering we are firmly convinced that noninterference is the best and wisest policy.

In cases which are carried to a successful result the discharge will diminish by degrees, the extreme pain will gradually subside, the convalescent will begin timidly to rest his foot upon the ground, and presently to bear weight upon it, and perhaps, after a long and tedious process of recuperation, he may be returned to his former and normal condition of usefulness. When the discharge has wholly ceased and the wounds are entirely healed, a blister covering the whole of the joint for the purpose of stimulating the absorption of the exudation will be of great service. If, on the contrary, there is no amelioration of symptoms and the progress of the disease resists every attempt to check it; if the discharge continues to flow not only without abatement but in an increased volume, and not alone by a single opening but by a number of fistulous tracts which have successively formed; if it seems evident that this drainage is rapidly and painfully sapping the suffering animal's vitality, and a deficient vis vitae fails to cooperate with the means of cure--all rational hope of recovery may be finally abandoned. Any further waiting for chances, or time lost in experimenting, will be mere cruelty and there need be no hesitation concerning the next step. The poor beast is under sentence of death, and every consideration of interest and of humanity demands an anticipation of nature's evident intent in the quick and easy execution of the sentence.

One of the essentials of treatment, and probably an indispensable condition when recovery is in any wise attainable, is the suspension of the patient in slings. He should be continued in them so long as he can be made to submit quietly to their restraint.

DISLOCATIONS.

Dislocations and luxations are interchangeable terms, meaning the separation and displacement of the articulating surfaces of the bones entering into the formation of a joint. This injury is rarely encountered in our large animals on account of the combination of strength and solidity in the formation of their joints. It is met with but seldom in cattle and less so in horses, while dogs and smaller animals are more often the sufferers.

Cause.--The accident of a luxation is less often encountered in the animal races than in man. This is not because the former are less subject to occasional violence involving powerful muscular contractions, or are less often exposed to casualties similar to those which result in luxations in the human skeleton, but because it requires the cooperation of conditions--anatomical, physiological, and perhaps mechanical--present in the human race and lacking in the others, which, however, can not in every case be clearly defined. Perhaps the greater relative length of the bony levers in the human formation may constitute a cause of the difference.

Among the predisposing causes in animals may be enumerated caries of articular surfaces, articular abscesses, excessive dropsical conditions, degenerative softening of the ligaments, and any excessive laxity of the soft structures.

Symptoms and diagnosis.--Three signs of dislocation must usually be taken into consideration. They are: (1) An alteration in the shape of the joint and in the normal relationship of the articulating surfaces; (2) an alteration in the length of the limb, either shortening or lengthening; (3) an alteration in the movableness of the joint, usually an unnatural immobility. Only the first, however, can be relied upon as essential. Luxations are not always complete; they may be partial; that is, the articulating surfaces may be displaced but not separated. In such cases several symptoms may not be present. And not only may the third sign be absent, but the mobility of the first be greatly increased when the character of the injury has been such as to produce extensive lacerations of the articular ligaments.

In addition to the above signs, a luxation is usually characterized by pain, swelling, hemorrhage beneath the skin from damaged or ruptured blood vessels, and even paralysis, when important nerves are pressed on by the displaced bones.

Sometimes a bone is fractured in the immediate vicinity of a joint. The knowledge of this fact requires us to be able to diagnose between a dislocation and such a fracture. In this we generally have three points to assist us: (1) The immobility of a dislocated joint as against the apparently remarkable freedom of movement in fracture; (2) in a dislocation there is no true crepitus--that peculiar grating sensation heard as well as felt on rubbing together the rough ends of fractured bones; however, it must be remembered that in a dislocation two or three days old the inflammatory changes around the joint may give rise to a crackling sensation similar to that in fracture; (3) as a rule, in luxations, if the ligamentous and muscular tissues about the joint are not badly torn, the displacement, when reduced, does not recur.

Prognosis.--The prognosis of a luxation is comparatively less serious than that of a fracture, though at time the indications of treatment may prove to be so difficult to apply that complications of a very severe character may arise.

Treatment.--The treatment of luxations must, of course, be similar to that of fractures. Reduction, naturally, will be the first indication in both cases, and the retention of the replaced parts must follow. The reduction involves the same steps of extension and counter extension, performed in the same manner, with the patient subdued by anesthetics.

The difference between the reduction of a dislocation and that of a fracture consists in the fact that in the former the object is simply to restore the bones to their true, normal position, with each articular surface in exact contact with its companion surface, the apparatus necessary afterwards to keep them in situ being similar to that which is employed in fracture cases, and which will usually require to be retained for a period of from 40 to 50 days, if not longer, before the ruptured retaining ligaments are sufficiently firm to be trusted to perform their office unassisted. A variety of manipulations are to be used by the surgeon, consisting in pushing, pulling, pressing, rotating, and, indeed, whatever movement may be necessary, until the bones are forced into such relative positions that the muscular contraction, operating in just the right directions, pulls the opposite matched ends together in true coaptation--a head into a cavity, an articular eminence into a trochlea, as the case may be. The "setting" is accompanied with a peculiar, snapping sound, audible and significant, as well as a visible return of the surface to its normal symmetry.

Special dislocations.--While all the articulations of the body are liable to this form of injury, there are three in the large animals which may claim a special consideration, viz:

THE SHOULDER JOINT.

We mention this displacement without intending to imply the practicability of any ordinary attempt at treatment, which is usually unsuccessful, the animal whose mishap it has been to become a victim to it being disabled for life. The superior head of the arm bone as it is received into the lower cavity of the shoulder blade is so situated as to be liable to be forced out of place in four directions. It may escape from its socket, according to the manner in which the violence affects it--outward, inward, backward, or forward--and the deformity which results and the effects which follow will correspondingly differ. We have said that treatment is generally unsuccessful. It may be added that the difficulties which interpose in the way of reduction are nearly insurmountable, and that the application of means for the retention of the parts after reduction would be next to impossible. The prognosis, from any point of view, is sufficiently grave for the luckless animal with a dislocated shoulder.

THE HIP JOINT.

This joint partakes very much of the characteristics of the humero-scapular articulation, but is more strongly built. The head of the thigh bone is more separated, or prominent and rounder in form, and the cup-like cavity, or socket, into which it fits is much deeper, forming together a deep, true ball-and-socket joint, which is, moreover, reenforced by two strong cords of funicular ligaments, which unite them. It will be easily comprehended, from this hint of the anatomy of the region, that a luxation of the hip joint must be an accident of comparatively rare occurrence; yet cases are recorded in which the head of the bone has been affirmed to slip out of its cavity and assume various positions--inward, outward, forward, or backward.

The indications of treatment are those of all cases of dislocation. When the reduction is accomplished the surgeon will be apprised of the fact by the peculiar, snapping sound usually heard on such occasions.

PSEUDO-LUXATIONS OF THE PATELLA.

This is not a true dislocation. The stifle bone is so peculiarly articulated with the thigh bone that the means of union are of sufficient strength to resist the causes which usually give rise to luxations, yet there is sometimes discovered a peculiar, pathological state in the hind legs of animals, the effect of which is closely to simulate the manifestation of many of the general symptoms of dislocations. This condition originates in muscular cramps, the action of which is seen in a certain change in the coaptation of the articular surfaces of the stifle and thigh bone, resulting in the exhibition of a sudden and alarming series of symptoms which have suggested the phrase of "stifle out" as a descriptive term.

Symptoms.--The animal so affected stands quietly and firmly in his stall, or perhaps with one of his hind legs extended backward, and resists every attempt to move him backward. If urged to move forward he will either refuse or comply with a jump, with the toe of the disabled leg dragging on the ground and brought forward by a second effort. There is no flexion at the hock and no motion at the stifle, while the circular motion of the hip is quite free. The leg appears to be much longer than the other, owing to the straightened position of the thigh bone, which forms almost a straight line with the tibia from the hip joint down. The stifle joint is motionless, and the motions of all the joints below it are more or less interfered with. External examination of the muscles of the hip and thigh reveals a certain degree of rigidity, with perhaps some soreness, and the stifle bone may be seen projecting more or less on the outside and upper part of the joint.

This state of things may continue for some time and until treatment is applied, or it may spontaneously and suddenly terminate, leaving everything in its normal condition, but perhaps to return again.

Cause.--Pseudo-dislocation of the patella is liable to occur under many of the conditions which cause actual dislocation, and yet it may often occur in animals which have not been exposed to the ordinary causes, but which have remained at rest in their stables. Sometimes these cases are assignable to falls in a slippery stall, or perhaps slipping when endeavoring to rise; sometimes to weakness in convalescing patients; sometimes to lack of tonicity of structure and general debility; sometimes to relaxation of tissues from want of exercise or use. A straight leg, sloping croup, and the young are predisposed to this dislocation.

Treatment.--The reduction of these displacements of the patella is not usually attended with difficulty. A sudden jerk or spasmodic action will often be all that is required to spring the patella into place, when the flexion of the leg at the hock ends the trouble for the time. But this is not always sufficient, and a true reduction may still be indicated. To effect this the leg must be drawn well forward by a rope attached to the lower end, and the patella, grasped with the hand, forcibly pushed forward and inward and made to slip over the outside border of the trochlea of the femur. The bone suddenly slips into position, the excessive rigor of the leg ceases with a spasmodic jerk, and the animal may walk or trot away without suspicion of lameness. Though this may end the trouble for the time, and the restoration seem to be perfect and permanent, a repetition of the entire transaction may subsequently take place, and perhaps from the loss of some proportion of tensile power which would naturally follow the original attack in the muscles involved the lesion might become a habitual weakness.

Warm fomentations and douches with cold water will often promote permanent recovery, and liberty in a box stall or in the field will in many cases insure constant relief. The use of a high-heeled shoe is recommended by European veterinarians. The use of stimulating liniments, with frictions, charges, or even severe blisters, may be resorted to in order to prevent the repetition of the difficulty by strengthening and toning up the parts.

DISEASES OF MUSCLES AND TENDONS.

SPRAINS.

This term expresses a more or less complete laceration or yielding of the fibers of the muscles, tendons, or the sheaths surrounding and supporting them. The usual cause of a sprain is external violence, such as a fall or a powerful exertion of strength, with following symptoms of soreness, heat, swelling, and a suspension of function. Their termination varies from simple resolution to suppuration, and commonly fibrinous exudation difficult to remove. None of the muscles or tendons of the body are exempt from liability to this lesion, though naturally from their uses and the exposure of their situation the extremities are more liable than other regions to become their seat. The nature of the prognosis will be determined by a consideration of the seat of the injury and the complications likely to arise.

Treatment.--The treatment will resolve itself into the routine of local applications, including warm fomentations, stimulating liniments, counterirritation by blistering, and in some cases even firing. Rest, in the stable or in a box stall, will be of advantage by promoting the absorption of whatever fibrinous exudation may have formed, or absorption may be stimulated by the careful persevering application of iodin in the form of ointments of various degrees of strength.

There are many conditions in which not only the muscular and tendinous structures proper are affected by a strain, but, by contiguity of parts, the periosteum of neighboring bones may become involved, with a complication of periostitis and its sequelae.

LAMENESS OF THE SHOULDER.

The frequency of the occurrence of lameness in the shoulder from sprains entitles it to precedence of mention in the present category, for, though so well covered with its muscular envelope, it is often the seat of injuries which, from the complex structure of the region, become difficult to diagnosticate with satisfactory precision and facility. The flat bone which forms the skeleton of that region is articulated in a comparatively loose manner with the bone of the arm, but the joint is, notwithstanding, rather solid, and is powerfully strengthened by tendons passing outside, inside, and in front of it. Still, shoulder lameness or sprain may exist, originating in lacerations of the muscles, the tendons or the ligaments of the joint, or perhaps in diseases of the bones themselves. "Slip of the shoulder" is a phrase frequently applied to such lesions.

The identification of the particular structures involved in these lesions is of much importance, in view of its bearing upon the question of prognosis. For example, while a simple superficial injury of the spinatus muscles, or the muscles by which the leg is attached to the trunk, may not be of serious import and may readily yield to treatment, or even recover spontaneously and without interference, the condition is quite changed in a case of tearing of the flexor brachii, or of its tendons as they pass in front of the articulation, or, what is still more serious, if there is inflammation or ulceration in the groove over which this tendon slides, or upon the articular surfaces or their surroundings, or periostitis at any point adjacent.

Causes.--The frequency of attacks of shoulder lameness is not difficult to account for. The superficial and unprotected position of the part and the numerous movements of which it is capable, and which, in fact, it performs, render it both subjectively and objectively preeminently liable to accident or injury. It would be difficult and would not materially avail to enumerate all the forms of violence by which the shoulder may be crippled. A fall, accompanied with powerful concussion; a violent muscular contraction in starting a heavily loaded vehicle from a standstill; a misstep following a quick muscular effort; a jump accompanied with miscalculated results in alighting; a slip on a smooth, icy road; balling the feet with snow; colliding with another horse or other object--indeed, the list may be indefinitely extended, but without profit or utility.

Symptoms.--Some of the symptoms of shoulder lameness are peculiar to themselves, and yet the trouble is frequently mistaken for other affections--navicular disease more often than any other. The fact that in both affections there are instances when the external symptoms are but imperfectly defined, and that one of them especially is very similar in both, is sufficient to mislead careless or inexperienced observers and to occasion the error which is sometimes committed of applying to one disease the name of the other, erring both ways in the interchange. The true designation of pathological lesions is very far at times from being of certain and easy accomplishment, and, owing to the massive structure of the parts we are considering, this is especially true in the present connection. Still there are many cases in which there is really no reasonable excuse for an error in diagnosis by an average practitioner.

Shoulder lameness will, of course, manifest itself by signs and appearances more or less distinct and pronounced, according to the nature of the degrees and the extent of the originating cause. We summarize some of these signs and appearances:

The lameness is not intermittent, but continued, the disturbance of motion gaging the severity of the lesion and its extent. It is more marked when the bones are diseased than when the muscles alone are affected. When in motion the two upper bony levers--the shoulder blade and the bone of the upper arm--are reduced to nearly complete immobility and the walking is performed by the complete displacement of the entire mass, which is dragged forward without either flexion of extension. The action of the joint below, as a natural consequence, is limited in its flexion. In many instances there is a certain degree of swelling at the point of injury--at the joint, or, more commonly, in front of it, or on the surface of the spinatus muscle. Again, instead of swelling there will be muscular atrophy, though, while this condition of loss of muscular power may interfere with perfect locomotion, it is not in itself usually a cause of shoulder lameness. "Sweenied" shoulders are more often due to disease below the fetlock than to affections above the elbow.

During rest the animal often carries his leg forward, somewhat analogous to the "pointing" position of navicular disease, though in some cases the painful member drops at the elbow in a semiflexed position. The backing is sometimes typical, the animal when performing it, instead of flexing his shoulder, dragging the whole leg without motion in the upper segment of the extremity.

The peculiar manner in which the leg is brought forward in the air for another step in the act of walking or trotting is in some instances characteristic of injuries of the shoulder. The lameness also manifests itself in bringing the leg forward with a circumflex swinging motion and a shortening in the extension of the step. The foot is carried close to the ground and stumbling is frequent, especially on an uneven road.

With the utmost scrutiny and care the vagueness and uncertainty of the symptoms will contribute to perplex and discredit the diagnosis and embarrass the surgeon, and sometimes the expedient is tried of aggravating the symptoms by way of intensifying their significance, and thus rendering them more intelligible. This has been sought by requiring the patient to travel on hard or very soft ground and compelling him to turn on the sound leg as a pivot, with other motions calculated to betray the locality of the pain.

Treatment.--It is our conviction that lameness of the shoulder will in many cases disappear with no other prescription than that of rest. Provided the lesions occasioning it are not too severe, time is all that is required. But the negation of letting alone is seldom accepted as a means of doing good, in the place of the active and the positive forms of treatment. This is in accordance with a trait of human nature which is universal, and is unlimited in its applications; hence something must be done. In mild cases of shoulder lameness, then, the indications are water, either in the cold douche or by showering, or by warm fomentations. Warm, wet blankets are of great service; in addition, or as alternative, anodyne liniments, camphor, belladonna, either in the form of tincture or the oils, are of benefit, and at a later period stimulating friction with suitable mixtures, sweating liniments, blistering compounds, subcutaneous injections over the region of the muscle of 1-1/2 grains of veratrin (the variety insoluble in water) mixed in 2 drams of water, etc., will find their place, and finally, when necessity demands it, the firing iron and the seton.

The duration of the treatment must be determined by its effects and the evidence that may be offered of the results following the action of the reparative process. But the great essential condition of cure, and the one without which the possibility of relapse will always remain as a menace, is, as we have often reiterated in analogous cases, rest, imperatively rest, irrespective of any other prescriptions with which it may be associated.

SPRAIN OF THE ELBOW MUSCLES.

Causes.--This injury, which fortunately is not very common, is mostly encountered in cities among heavy draft horses or rapidly driven animals which are obliged to travel, often smooth shod, upon slippery, icy, or greasy pavements, where they are easily liable to lose their foothold. The region of the strain is the posterior part of the shoulder, and the affected muscles are those which occupy the space between the posterior border of the scapula and the posterior face of the arm. It is the muscles of the olecranon which give way.

Symptoms.--The symptoms are easily recognized, especially when the animal is in action. While at rest the attitude may be normal, or by close scrutiny a peculiarity may perhaps be detected. The leg may seem to drop; the elbow may appear to be lower than its fellow, with the knee and lower part of the leg flexed and the foot resting on the toe, with the heel raised. Such an attitude, however, may be occasionally assumed by an animal without having any special significance, but when it becomes more pronounced in motion the fact acquires a symptomatic value, and this is the case in the present instance. A rapid gait becomes quite impossible, and the walk, as in some few other diseases, becomes sufficiently characteristic to warrant a diagnosis even when observed from a distance. An entire dropping of the anterior part of the trunk becomes manifest, and no weight is carried on the disabled side in consequence of the loss of action in the suspensory muscles. There are often heat, pain, and swelling in the muscular mass at the elbow, though at times a hollow, or depression, may be observed near the posterior border of the scapula, which is probably the seat of injury.

These hurts are of various degrees of importance, varying from mere minor casualties of quick recovery to lesions which are of sufficient severity to render an animal useless and valueless for life.

Treatment.--The prime elements of treatment, which should be strictly observed, are rest and quiet. Prescriptions of all kinds, of course, have their advocates. Among them are ether, chloroform, camphor, alcoholic frictions, warm fomentations, blisters, setons, etc. Unless the conclusions of experience are to be ignored, my own judgment is decisive in favor of rest, judiciously applied, however, and my view of what constitutes a judicious application of rest has been more than once presented in these pages. There are degrees of this rest. One contemplates simple immobility in a narrow stall. Another means the enforced mobility of the slings and a narrow stall as well. Another a box stall, with ample latitude as to posture and space, and option to stand or lie down. As wide as this range may appear to be, radical recovery has occurred under all of these modified forms of letting our patients alone.

HIP LAMENESS.

The etiology of injuries and diseases of the hip is one and the same with that of the shoulder. The same causes operate and the same results follow. The only essential change, with an important exception, which would be necessary in passing from one region to the other in a description of its anatomy, its physiology, and its pathology would be a substitution of anatomical names in reference to certain bones, articulations, muscles, ligaments, and membranes concerned in the injuries and diseases described. It would be only a useless repetition to cover again the ground over which we have so recently passed in recital of the manner in which certain forms of external violence (falls, blows, kicks, etc.) result in other certain forms of lesion (luxation, fracture, periostitis, ostitis, etc.), and to recapitulate the items of treatment and the names of the medicaments proper to use. The same rules of diagnosis and the same indications and prognosis are applicable equally to every portion of the organism, with only such modifications in applying dressings and apparatus as may be required by differences of conformation and other minor circumstances, which must suggest themselves to the judgment of every experienced observer when the occasion arrives for its exercise.

An exception is to be made, while considering the subject in connection with the region now under advisement, in respect to the formidable affection known as morbus coxarius, or hip-joint disease; and leaving the detail of other lesions to take their place under other heads, that relating to the shoulder, for instance, we turn to the hip joint and its ailments as the chief subject of our present consideration.

Symptoms.--In investigating for morbus coxarius, let the observer first examine the lame animal by scanning critically the outlines of the joint and the region adjacent for any difference of size or disturbance of symmetry in the parts, any prominence or rotundity, and on both sides. The lame side will probably be warmer, more developed, and fuller, both to the touch and to the eye. Let him then grasp the lower part of the leg (as he would in examining a case of shoulder lameness) and endeavor to produce excessive passive motion. This will probably cause pain when the leg is made to assume a given position. Let him push the thigh forcibly against the hip bone, and the contact will again probably cause a manifestation of pain. If the horse is trotted, the limited action of the hip joint proper and the excessive dropping and rising of the hip of the opposite side will be easily recognized. Usually the animal does not extend the foot so far as customarily and picks it up much sooner.

The abductive or circumflex motion observed in shoulder lameness is also present in hip lameness, but under special conditions, and the test of the difficulty, either by traveling on soft ground or in turning the horse in a circle, may here also contribute to the diagnosis, as in testing for lameness in the anterior extremity.

Prognosis.--The prognosis of hip lameness is at times quite serious, not only on account of the long duration of treatment required to effect good results, and because of the character which may be assumed by the disease, but of the permanence of the disability resulting from it. Exostosis and ulcerative arthritis are sequelae which often resist every form of treatment.

Treatment.--As before intimated, this is little more than a repetition of the remarks upon the lameness of the shoulder, with slight modifications occasioned by the muscular structure of the hip, and we are limited to the same recommendations of treatment. The advantages of rest must be reaffirmed, with local applications, of which, however, it may be said that they are more distinctly indicated and likely to be more effective in their results than in shoulder lameness, and may be more freely employed, whether in the form of liniments, blisters (singly or repeated), firing, or setoning.

SPRAINS OF SUSPENSORY LIGAMENTS AND OF FLEXOR TENDONS OR THEIR SHEATHS.

The fibrous structure situated behind the cannon bones, both in the fore and hind legs, is often the seat of lacerations or sprains resulting from violent efforts or sudden jerks.

Cause.--The injury may be considered serious or trifling, according to the circumstances of each case as judged by its own history. Among the predisposing causes are a long, thin fetlock and a narrow knee or hock as viewed from the side, with the flexor muscles tied in just below the joint. The longer and more oblique the pastern the greater is the strain on the flexor tendons and suspensory ligaments; hence a low quarter, a toe calk, and no heel calks, or a thin calk placed at the tip under the toe, and leaving the quarters long abnormally stretches the back tendons and causes a great strain upon them just before the weight is shifted from the foot in locomotion. In runners and hunters the disease is liable to be periodic. In driving horses it is most common in well-bred animals of nervous temperament. Draft horses suffer most frequently in the hind legs.

Symptoms.--The injury is readily recognized by the changed aspect of the region and the accompanying local symptoms. The parts which in health are well defined, with the outlines of the tendons and ligaments well marked, become the seat of a swelling, more or less developed, from a small spot on the middle of the back of the tendon to a tumefaction reaching from the knee down to and even involving the fetlock itself. It is always characterized by heat, and it is variously sensitive, ranging from a mere tenderness to a degree of soreness which shrinks from the lightest touch. The degree of the lameness varies, and it has a corresponding range with the soreness, sometimes showing only a slight halting and at others the extreme of lameness on three legs, with intermediate degrees.

The lameness is always worse when the weight is thrown on the foot and is most marked toward the end of the phase of contact with the ground. Either passive irritation of the leg or turning the animal in a circle causes pain as in diseases of the joints. Sometimes the horse likes to get the heels on a stone or some elevation so as to relieve the weight from the flexor tendons. Finally, in cases of long standing, a shortening of the tendons occurs, resulting in the abnormal flexion of the foot known by horsemen as "broken down," or a more upright position of the foot may follow, producing perhaps knuckling or the so-called clubfoot.

Prognosis.--It may be safely assumed on general principles that a leg which has received such injuries seldom returns to a perfect condition of efficiency and soundness, and that as a fact a certain absolute amount of thickening and deformity will remain permanent, even when the lameness has entirely disappeared.

Treatment.--The injured member should receive the earliest attention possible, not only when the inflammatory condition is present, but when it is subsiding and there is only the thickening of the ligaments, the tendons, or the sheath.

The most important remedy is rest, and the shoes should always be removed. During the first three days cold in the form of immersion or continuous irrigation is indicated. Then warm moisture and continuous pressure are advised. The latter is best applied by placing two padded splints about the thickness of the thumb along the two sides of the tendon and binding them in place with even pressure by bandage. Frequent bathing with warm soap suds is also beneficial. The absorption of the exudate may be promoted and the work of restoration effected by frictions with alcohol, tincture of soap, spirits of camphor, mild liniments, strong, sweating liniments, and blisters. An excellent ointment to apply with massage consists of equal parts of blue ointment and green soap, with double the quantity of vaseline. The action of blisters in these cases depends chiefly upon the massage used in applying them and upon the continuous pressure of the swollen skin on the inflamed tendons. In old cases more beneficial results will follow line firing. In these cases shoeing is very important. Leave the quarters long, shorten the toe, give the shoe rolling motion, and either put short heel calks on the branches or thicken the branches. Although this line of treatment is efficacious in many cases, there are others in which the thickening of the tendons refuses to yield and the changed tissues remain firmly organized, leaving them in the form of a thick mass resting upon the back part of the cannon bone.

KNUCKLING OF FETLOCK.

As a consequence of the last-mentioned lesion of the tendons, a new condition presents itself in the articular disposition, constituting the deformity known as the knuckling fetlock. (See also p. 400.)

By this is meant a deformity of the fetlock joint by which the natural angle is changed from that which pertains to the healthy articulation. The first pastern, or suffraginis, loses its oblique direction and assumes another, which varies from the upright to the oblique, from before backward, and from above downward; in other words, forming an angle with its apex in front.

Causes.--This condition, as we have seen, may be the result of chronic disease producing structural changes in the tendons, and it may also occur as the result of other affections or some peculiarity independent of this and situated below the fetlock, such as ringbones, sidebones, or traumatic disease of the foot proper. Animals are sometimes predisposed to knuckling, such, for example, as are naturally straight in their pasterns, or animals which are compelled to labor when too young. The hind legs are more predisposed than the fore to this deformity, in consequence of the greater amount of labor they are required to perform as the propelling levers of the body.

Symptoms.--The symptoms of knuckling are easily recognized. The changes in the direction of the bones vary more or less with the degree of the lesion, sometimes assuming such a direction that it almost becomes a true dislocation of the pastern.

The effect of knuckling upon the gait also varies according to the degree of the deformity. As the different degrees of the shortening of the leg affect the motion of the fetlock, the lameness may be very slight or quite extreme. Another consequence of this shortening is such a change in the position of the foot that the heels cease to come in contact with the ground and assume a greater elevation, and the final result of this is soon witnessed in the development of a clubfoot.

Treatment.--To whatever cause the knuckling may be ascribed, it is always a severe infirmity, and there is but little room for hoping to overcome it unless it be during the very first stages of the trouble, and the hope dwindles to still smaller dimensions when it is secondary to other diseases below the fetlock. If it is caused by overworking the animal, the first indication, of course, will be rest. Line firing has proved very efficacious in these cases. The animal must be turned loose and left unemployed. Careful attention should be given to the condition of his feet and to the manner of shoeing, while time is allowed for the tendons to become restored to their normal state and the irritation caused by excessive stretching has subsided. A shoe with a thick heel will contribute to this. If no improvement can be obtained, however, and the tendons though retracted have yet been relieved of much of their thickening, the case is not a desperate one, and may yet be benefited by the operation of tenotomy, single or double--an operative expedient which must be committed to the experienced surgeon for its performance.

SPRUNG KNEES.

Though not positively the result of diseases of the tendons acting upon the knees, we venture to consider this deformity in connection with that which we have just described. It consists in such an alteration in the direction and articulation of the bones which form the various carpal joints that instead of forming a vertical line from the lower end of the forearm to the cannon bone they are so united that the knee is more or less bent forward, presenting a condition caused by the retraction of two of the principal muscles by which the cannon bone is flexed.

Cause.--This flexion of the knee may be a congenital deformity and have continued from the foaling of the animal; or, like clubfoot, it may be the result of heavy labor which the animal has been compelled to perform when too young. It may also be due to other diseases existing in parts below the knee joint.

Symptoms.--This change of direction largely influences the movement of the animal by detracting from its firmness and practically weakening the entire frame, even to the extent of rendering him insecure on his feet and liable to fall. This condition of weakness is sometimes so pronounced that he is exposed to fall even when standing at rest and unmolested, the knees being unable even to bear their portion of the mere weight of the frame. This results in another trouble--that of being unable to keep permanently upright. He is liable to fall on his knees, and by this act becomes presently a sufferer from the lesion known by the term of "broken knees."

Treatment.--Whatever may be the originating cause of this imperfection, it detracts very largely from the usefulness and value of a horse, disqualifying him for ordinary labor and wholly unfitting him for service under the saddle without jeopardizing the safety of his rider. If, however, the trouble is known from the start, and is not the result of congenital deformity or weakness of the knee joint, or secondary to other diseases, rest, with fortifying frictions, may sometimes aid in strengthening the joints; and the application of blisters on the posterior part of the knee, from a short distance above to a point a little below the joint, may be followed by some satisfactory results; but with this trouble, as with knuckling fetlocks, the danger of relapse must be kept in mind as a contingency always liable to occur.

CURB.

This lesion is the bulging backward of the posterior part of the hock, where in the normal state there should be a straight line, extending from the upper end of the point of the hock down to the fetlock.

Cause.--The cause may be a sprain of the tendon which passes on the posterior part of the hock, or of one of its sheaths, or of the strong ligament situated on the posterior border of the os calcis.

Hocks of a certain conformation seems to possess a greater liability to curb than others. They are overbent, coarse, and thick in appearance, or may be too narrow from front to back across the lower portion. This condition may therefore result as a sequence to congenital malformation, as in the case of horses that are "saber-legged." It often occurs, also, as the result of violent efforts, of heavy pulling, of high jumping, or of slipping; in a word, it may result from any of the causes heretofore considered as instrumental in producing lacerations of muscular, tendinous, or ligamentous structure.

Symptoms.--A hock affected with curb will present at the outset a swelling more or less diffuse on its posterior portion, with varying degrees of heat and soreness, and these will be accompanied with lameness of a permanent character. At a later period, however, the swelling will become better defined, the deformity more characteristic, the prominent, curved line readily detected, and the thickness of the infiltrated tissue easily determined by the fingers. At this time, also, there may be a condition of lameness, varying in degree, while at others, again, the irregularity of action at the hock will be so slight as to escape detection, the animal betraying no appearance of its existence.

A curb constitutes, by a strict construction of the term, an "unsoundness," since the hock thus affected is less able to endure severe labor, and is more liable to give way with the slightest effort. Yet the prognosis of a curb can not be considered to be serious, as it generally yields to treatment, or at least the lameness it may occasion is generally easily relieved, though the loss of contour caused by the bulging will always constitute a blemish.

Treatment.--On the first appearance of a curb, when it exhibits the signs of an acute inflammation, the first indication is to subdue it by the use of cold applications, as intermittent or constant irrigation or an ice poultice; when these have exhausted their effect and the swelling has assumed better defined boundaries, and the infiltration of the tendons or of the ligaments is all that remains of a morbid state, then every effort must be directed to the object of effecting its absorption and reducing its dimensions by pressure and other methods. The medicaments most to be trusted are blisters of cantharides and frictions with ointments of iodin, or, preferably, biniodid of mercury. Mercurial agents alone, by their therapeutic properties or by means of the artificial bandages which they furnish by their incrustations when their vesicatory effects are exhausted, will give good results in some instances by a single application, and often by repeated applications. The use of the firing iron must, however, be frequently resorted to, either to remove the lameness or to stimulate the absorption. We believe that its early application ought to be resorted to in preference to waiting until the exudation is firmly organized. Firing in dull points or in lines will prove as beneficial in curb as in any other disease of a similar nature.

LACERATED TENDONS.

This form of injury, whether of a simple or of a compound character, may become a lesion of a very serious nature, and will usually require long and careful treatment, which may yet prove unavailing in consequence either of the intrinsically fatal character of the wound itself or the complications which have rendered it incurable.

Cause.--Like all similar injuries, they are the result of traumatic violence, such as contact with objects either blunt or sharp; a curb-stone in the city; in the country, a tree stump or a fence, especially one of wire. It may easily occur to a runaway horse when he is "whipped" with fragments of harness or "flogged" by fragments of splintered shafts "thrashing" his legs, or by the contact of his legs with the wagon he has overturned and shattered with his heels while disengaging himself from the wreck.

Symptoms.--It is not always necessary that the skin be involved in this form of injury. On the contrary, the tegument is frequently left entirely intact, especially when the injury follows infectious diseases or occurs during light exercise after long periods of rest in the stable. Again, the skin may be cut through and the tendons nearly severed. A point a little above the fetlock is usually the seat of the injury. But irrespective of this, and whether the skin is or is not implicated, the symptoms resemble very much those of a fracture. There is excessive mobility, at least more than in a normal state, with more or less inability to carry weight. There may be swelling of the parts, and on passing the hands carefully along the tendon to the point of division the stumps of the divided structure will be felt more or less separated, perhaps wholly divided. The position of the animal while at rest and standing is peculiar and characteristic. While the heels are well placed on the ground, the toe is correspondingly elevated, with a tendency to turn up--a form of breaking down which was described when speaking of the fracture of the sesamoids. Carrying weight is done only with considerable difficulty, but with comparatively little pain, and the animal will unconsciously continue to move the leg as if in great suffering, notwithstanding the fact that his general condition may be very good and his appetite unimpaired.

The effect upon the general organism of compound lacerated wounds of tendinous structures, or those which are associated with injuries of the skin, are different. The wound becomes in a short time the seat of a high degree of inflammation, with abundant suppuration filling it from the bottom; the tendon, whether as the result of the bruise or of the laceration, or of maceration in the accumulated pus, undergoes a process of softening, and necrosis and sloughing ensue. This complicates the case and probably some form of tendinous synovitis follows, running into suppurative arthritis, to end, if close to a joint, with a fatal result.

Prognosis.--The prognosis of lacerated tendons should be very conservative. Under the most favorable circumstances a period of from six weeks to two months will be necessary for the treatment, before the formation of the cicatricial callus and the establishment of a firm union between the tendinous stumps.

Treatment.--As with fractures, and even in a greater degree, the necessity is imperative, in the treatment of lacerated tendons, to obtain as perfect a state of immobility as can be obtained compatibly with the disposition of the patient; the natural opposition of the animal, sometimes ill-tempered and fractious at best, under the necessary restraint causing at times much embarrassment to the practitioner in applying the necessary treatment. Without the necessary immobility there can be no close connection of the ends of the tendons. To fulfill this necessary condition the posterior part of the foot and the fetlock must be supported and the traction performed by them relieved, an object which can be obtained by the use of the high-heeled and bar shoe, or possibly better accomplished with a shoe of the same kind extending about 2 or 2-1/2 inches back of the heels. The perfect immobility of the legs is obtained in the same way as in the treatment of fracture, with splints, bandages, iron apparatus, plaster of adhesive mixtures, and similar means. So long as the dressings remain in place undisturbed and no chafing or other evidence of pain is present, the dressings may be continued without changing, the patient being kept in the slings for a period sufficient to insure the perfect union of the tendons. For a compound lesion when there is laceration of the skin some special care is necessary. The wound must be carefully watched and the dressings removed at intervals of a few days or as often as may be needful, all of which additional manipulation and extra nursing, however indispensable, still adds to the gravity of the case and renders the prognosis more and more serious. When the tendons have sloughed in threads of various dimensions, or if in the absence of this process of mortification healthy granulations should form and fill up the wound, still very careful attention will be required, the granulating ends of the tendons having a tendency to bulge between the edges of the skin and to assume large dimensions, forming bulky excrescences or growths of a warty or cauliflower appearance, the removal of which becomes a troublesome matter.

The union of the tendons will at times leave a thickening of varying degree near the point of cicatrization, the absorption of which becomes an object of difficult and doubtful accomplishment, but which may be promoted by moderate blistering and the use of alterative and absorbent mixtures or perhaps the fire iron. A shoe with heels somewhat higher than usual will prove a comfort to the animal and aid in moderating and relieving the tension of the tendons.

RUPTURE OF THE FLEXOR METATARSI.

This is a muscle of the anterior part of the shank. It is situated in front of the tibia, and is of peculiar formation, being composed of a muscular portion with a very powerful tendon, which are at first distinct and separate, to be intimately united lower down, and terminating at the lower end by a division into four tendinous bands. It is a powerful muscle of the hinder shank bone, and also acts as a strong means of support for the stifle joint; that is, of the articulation of the thigh and shank bone, in front and outside of which it passes. Its situation and its use cause it to be liable to severe stretching and straining, and a rupture of some of its fibers is sometimes the consequence.

Cause.--This injury may be the result of a violent effort of the animal in leaping over a high obstacle; in missing his foothold and suddenly slipping backward while powerfully grasping the ground with the feet in striving to start a heavily loaded vehicle; in making a violent effort to prevent a probable fall; or in attempting to lift the feet from miry ground.

Symptoms.--The accident is immediately followed by disability which will vary according to the true seat of the injury and the period of its duration. This rupture will not prevent the horse from standing perfectly and firmly on his feet when kept at rest, and while no muscular efforts are required from him there is no appearance of any lesion or unsoundness. An attempt to move him backward, however, will cause him to throw all his weight upon his hind-quarters, and he will refuse to raise his foot from the ground. If compelled to do so, or required to move forward, the hock being no longer capable of flexion, the muscle which effects that movement being the injured one, the opposite muscles, the extensors, acting freely, the entire lower part of the leg, from the hock down, will be suddenly, with a jerk, extended on the tibia or shank bone, and simultaneously with this the tendo Achillis, the cord of the hock, the tendons of the extensors of the hock will be put in a wrinkled and relaxed condition. The leg is behind the animal and the toe rests on the ground. Examination of the fore part of the shank from the stifle down to the hock may reveal soreness, and possibly some swelling and heat at the seat of the lesion.

Treatment.--Our experience with injuries of this form convinces us that, generally speaking, they are amenable to treatment. Provided a sufficient time has been allowed for union to take place, very few instances in which radical recovery has not been effected have come to our knowledge. The more flexed the leg can be kept, the quicker will it heal.

In these cases, as in those of simple laceration of tendons, already considered, the indications resemble those which apply in the treatment of fractures, as near as coaptation of the lacerated ends is possible, with immobility, being the necessary conditions to secure. The first is a matter of very difficult accomplishment, by bandaging alone, and some have recommended instead the application of charges or blisters in order to compel the animal to keep more quiet.

To secure the necessary immobility the animal should be placed in slings snugly applied, and kept in a narrow stall. He should also be tied short, and restrained from any backward movement by ropes or boards, and should, moreover, be kept in as quiet a temper as possible by the exclusion of all causes of irritation or excitement. Weeks must then elapse, not less, but frequently more than six, often eight, before he can be considered out of danger and able to return to his labor, which should for a time be light and easy, and gradually, if ever, increased to the measure of a thoroughly sound and strong animal. If he is used too soon the newly formed tissue between the ends of the muscle will be liable to stretch and leave the flexor muscle too long and permanently displaced.

SUNDRY ADDITIONAL AFFECTIONS OF THE EXTREMITIES.

Among these there are three which will principally occupy our attention, and, which may be considered as forming a single group. In some parts of the legs may be found certain peculiar little structures of a saclike formation, containing an oily substance designed for the lubrication of the parts upon which they are placed for the purpose of facilitating the movements of the tendons which pass over them. These little sacs or muco-synovial capsules, under peculiar conditions of traumatism, are liable to become subject to a diseased process, which consists principally in a hypersecretion of their contents and an increase in dimensions, and they may undergo peculiar pathological changes of such character as to disable an animal, and in many instances to cause serious blemishes which can but depreciate its value. These growths, which are known as hygromata, may result from external violence, as blows or bruises, and may appear in the form of small, soft tumors, painless and not inflammatory in character, but, by a repetition of the cause or renewal of violence, liable to acquire increased severity. Severe inflammation, with suppuration, may follow, which, filling up the cavity, the walls will become thickened and hard, resulting in the formation of a tumor.

The elbow, the knee, and the hock are the parts of the body where these lesions are ordinarily found, and on account of their peculiar shape and the position they occupy they have received the denomination "capped." They will be considered in their peculiar aspect.

CAPPED ELBOW.

Capped elbow, or "shoe boil," is a term applied to an enlargement often found at the point of the elbow.

Cause.--This lesion is due to injury or pressure of the part while it is resting on the ground. The horse, unlike the cow, does not rest directly on the under surface of the sternum, or breastbone, on account of its sharp, ridge-like formation. He rests more on the side of the breastbone and chest, and consequently the leg which is flexed under the body is subject to considerable pressure. If the leg is flexed under the body so that the hoof or shoe is directly in contact with the elbow, which may occur in horses having an extremely long cannon bone or excessive length in the shoes, the greater part of the weight of the chest is concentrated at this point and the pressure may cause a bruise or an inflammation.

Symptoms.--Under these conditions the point of the elbow may become swollen and tender and exhibit heat and pain. This swelling may not only cover the point of the elbow, but sometimes reaches the axilla and assumes such proportions that there is great difficulty in using the leg, the animal showing signs of lameness even to the extent of the circumflex step, as in shoulder lameness. This edematous condition, however, does not remain stationary. It may by degrees subside or perhaps disappear. In the first instance it will become more distinctly defined, with better marked boundaries, until it is reduced to a soft, round, fluctuating tumor, with or without heat or pain. There is then either a bloody or serous tumor or a purulent collection, and following the puncture of its walls with the knife there will be an escape of blood, serum, or pus, as the case may be, in variable quantities. In either case, but principally in that of the cystic form, the tumor will be found to be subdivided by septa, or bands running in various directions.

Various changes will follow the opening of the tumor and the escape of its contents. In a majority of cases the process of cicatrization will take place, and the cavity fill up by granulation, the discharge, at first abundant, gradually diminishing and the wound closing, usually without leaving any mark. At times, however, and especially if the disease has several times repeated its course, there may remain a pendulous sac, partly obliterated, which a sufficient amount of excitement or irritation may soon restore to its previous dimensions and condition.

In other cases an entirely different process takes place. The walls of the cavity, cyst, or abscess become ulcerated and thickened, the granulations of the sac become fibrous in their structure and fill up the cavity, and it assumes the character of a hard tumor on the back of the elbow, sometimes partly and sometimes entirely covered by the skin. It is fibrous in its nature, painless to the touch, well defined in its contour, and may vary in size from that of a small apple to that of a child's head.

This last form of capped elbow is the most serious of any, resisting all known forms of mild treatment, and removable by the knife only. The other forms, even that with the inflammatory aspect and its large edematous swelling which interferes with the work of the animal, may justify a much milder prognosis, and, aside from their liability to recur, may be ranked with the comparatively harmless affections.

Treatment.--So long as the danger of recurrence is the principal bad feature of capped elbow the most important consideration is that of devising a means for its prevention. To prevent the animal from lying down is evidently the simplest method of keeping the heels and the elbow apart; but the impracticability of this prescription is apparent, since most animals are obliged to lie down when they sleep, though it is true that a few take their sleep on their feet. The question of shoeing here enters into the discussion. The shortening of the inside branch of the shoe, which is the one with which the pressure is made, may be of advantage, and especially if the truncated end of the shoe is smooth and filed over to remove all possibility of pressure and contusion upon the skin. The protection of the skin of the elbow by interposing soft tissues between that and the shoe, or by bandaging the heel with bags or covering it with boots, is considered by many the best of the preventive methods, and the advantage to be obtained by resorting to it can not be overlooked when the number of horses which develop shoe boil whenever the use of the boot is intermitted is considered. In order to prevent the animal from assuming the sternal decubitus, many give preference to the plan of fastening a piece of wood across the stall at some distance from the front wall or manger. It is a simple expedient, primitive, perhaps, but nevertheless practical, and followed by good results.

The therapeutic treatment is also important. The edematous swelling, when recognized by its external appearance and the existing inflammation, should be treated without delay. Warm fomentations, repeated several times daily, are then indicated, the degree of warmth being as high as can be borne comfortably. They are easily applied and often yield decided relief in a few hours. In some cases, however, astringents, in the form of poultices or pastes, are used in preference; these are made to cover the entire swelling and allowed to remain, drying after a short time, it is true, and perhaps falling off, but are easily renewed and reapplied. An excellent astringent for these cases is a putty made of powdered chalk and vinegar (acetate of lime), and the whole swelling is then covered with a thick coating of soft clay made into a mass with water.

These simple remedies are often all that is required. Under their use the swelling passes off by degrees and after a short interval the animal is fit for work again, but not uncommonly instead a swelling develops, puffy, not painful, and perhaps giving a sensation of crepitation when pressure is applied with the finger. It is soft, evidently contains a liquid, and when freely opened with a good-sized incision discharges a certain quantity of blood, partly liquid and partly coagulated, and perhaps a little hemorrhage will follow. The cavity should then be well washed out and a plug of oakum introduced, leaving a small portion protruding through the cut to prevent it from closing prematurely. It may be taken off the next day, and a daily cleansing will then be all that is necessary. In another case the tumor becomes very soft in its whole extent, with evident fluctuation and a well-defined form. The discharge of the fluid is then indicated, and a free incision will be followed by the escape of a quantity of thin yellowish liquid from a single sac. The wound should be kept clean and dressed frequently, in order to insure prompt healing. But if the cavity is found to be subdivided in its interior by numerous bands and the cyst proves to be multilocular the partitions should be torn out with the fingers and the cavity then treated in the same manner as the unilocular sac. In still another case the swelling may be warm and painful with indistinct fluctuation, or fluctuation only at a certain point. This indicates an abscess, and necessitates an incision to drain the pus, followed by the careful cleansing and dressing of the wound.

But cases occur in which all the treatment that has been described fails to effect a full recovery, and instead a fibrous tumor begins to develop. A change of treatment is, of course, then in order. The inflammation being chronic will necessitate stimulating treatment of the part in order to increase the process of absorption. We must again draw upon the resources of experience in the form of blisters, the fomentations, the iodin, and the mercurial ointments, as heretofore mentioned. Good results may always be insured from their judicious and timely administration. In applying the powerful mineral inunctions much patience and wisdom are required. It should be done by carefully and perseveringly rubbing in small quantities daily; it should be done softly and gently, not with force, nor with the expectation of producing an astonishing effect by heavy dosing and main strength in a few hours; it should be after the manner of a siege rather than that of a charge. The object is to induce the drugs to permeate the affected part until the entire mass is penetrated. Of course cases will be encountered which resist all forms of medical treatment. The tumor remains as a fixed fact; it continues to grow; it is large and pendulous at the elbow; its weight is estimated in pounds; it is not an eyesore merely, but an uncomfortable, burdensome mass, excoriating all the surrounding parts and being itself excoriated in turn; mild treatment has failed and is no longer to be relied on.

Resort must now be made to surgical methods, and here again we must choose between the ligature, the cautery, and the knife. Each has its advocates among practitioners. In a case like the present, one of the difficulties arises in connection with the application and retention of bandages and other dressings after the amputation has been performed. It is a somewhat difficult problem, owing to the conformation and proportions of the body of the patient, and involves the exercise of considerable practical ingenuity to adjust and retain the appliances necessary to insure a good final result.

In the long description of the treatment of the varieties of capped elbow I have thus far omitted any mention of one method which is practiced and commended by not a few. I refer to the use of setons, introduced through the tumor. My own experience and the observation of many failures from this method led me to abandon it.

CAPPED KNEE.

The passage of the tendons of the extensor muscle of the cannon, as it glides in front of the knee joint, is assisted by one of the little bursae before mentioned, and when this becomes the seat of dropsical collection a hygroma is formed and the knee is "capped." Though in its history somewhat analogous to the capped elbow, there are points of difference between them. Their development may prove a source of great annoyance from the fact of the blemish which they constitute.

Cause.--The capped knee presents itself under various conditions. It is sometimes the result of a bruise or contusion, often repeated, inflicted upon himself by a horse addicted to the habit of pawing while in the stable and striking the front of the stall with his knees. Another class of patients is formed of those weak-kneed animals which are subject to falling and bruising the front of the joint against the ground, the results not being always of the same character.

Symptoms.--The lesion may be a simple bruise, or it may be a severe contusion with swelling, edema, heat, and pain. The joint becomes so stiff and rigid that it interferes with locomotion and yet under careful simple treatment the trouble may disappear.

Again, instead of altogether passing off, the edema may diminish in extent, becoming more defined in form and may remain as a swelling on the front part of the knee. Resulting from the crushing of small blood vessels, this is necessarily full of blood. The swelling is somewhat soft, diffuse, not painful, more or less fluctuating, and after a few days becomes crepitant under the pressure of the hand.

Instead of being filled with blood the swelling may be full of serum, as often occurs when violence, though perhaps slight, has been frequently repeated. In that case the swelling is generally well defined, soft, and painless, with more or less fluctuation, and it may even become pendulous. In other cases the swelling may be of an acute, inflammatory nature, with heat and pain, accompanied with stiffness of the joint. This leads to the formation of an abscess. Whatever the nature of these swellings may be, either full of blood, serum, or pus, some blemish usually remains after treatment.

Prognosis.--Though simple bruises of the knee without extensive lesions are usually of trifling account, a different prognosis must be pronounced when the lesion assumes more important dimensions, and though a capped knee may be comparatively of little importance we have seen cases in which not only extensive blemishes were left to disfigure the patient, but the animals had become worthless in consequence of the extension of the diseased process to the various elements composing the joint, and giving rise to the most complicated cases of carpitis.

Treatment.--Usually the first symptom of trouble is the edematous swelling on the front of the "knee." The prevention of the inflammation and consequently of the abscess, is the prime object in view, and it may be realized by the use of warm-water fomentations or compresses applied over the swelling, which may be used either in a simple form or combined with astringents, such as Goulard's extract, alum, or sulphate of zinc. The application of warm poultices of oil meal or ground flaxseed, enveloping the whole joint and kept in place by bandages, is often followed by absorption of the swelling, or, if the abscess is in process of formation, by the active excretion of pus. If an abscess forms in spite of these precautions it may be treated surgically in several ways.

In one it should be done by a careful incision, which will allow the escape of the blood or the serum, or of the pus which is inclosed in the sac; in another it may be by means of a seton, in order that the discharge may be maintained and allowed to escape; for another we may adopt the more cautious manner of emptying the cavity by means of punctures with small trocars or aspirators. The danger attending this last method arises from the possible sloughing of large portions of the skin, while that attending the first is the hazard of the possibility of the extension of the inflammation to the capsular ligament of the knee, with the possibility of an open joint in prospect.

As we have remarked, the cavity after being emptied may rapidly close and leave in a short time but slight traces of its previous existence. But in many, if not in most cases, there will remain, after the cicatrization is complete, a thickening or organized exudation at one time round and well defined, at another spreading by a diffused infiltration, to which it will be necessary to give immediate attention, from the fact of its tendency to form into an organized and permanent body. To stimulate inflammation in this diseased structure, blisters are recommended, but chiefly for the purpose of promoting the process of absorption.

If this treatment fails, the use of iodin and mercurial preparations is recommended.

Plain mercurial or plain iodin ointment, or both in combination as iodid of mercury, are commonly used, and may be applied either moderately and by gentle degrees, as we have suggested, or more freely and vigorously with a view to more immediate effects, which, however, will also be more superficial. The use of the firing iron applied deeply with fine points is then to be strongly recommended, to be followed by blisters and various liniments. This course may generally be relied on as quite sure to be followed by satisfactory results.

While the treatment is in progress it will, of course, be necessary to secure the animal in such manner that a recurrence of the injury will be impossible from similar causes to those which were previously responsible.

CAPPED HOCK.

A bad habit of rubbing or striking the partitions of their stalls with their hocks prevails among some horses, with the result of an injury which shows itself on the upper points of those bones, the summit of the os calcis. From its analogy to the condition of capped elbow the designation of capped hock has been applied to this condition.

Symptoms.--A capped hock is therefore but the development of a bruise at the point of the hock, which if many times repeated may excite an inflammatory process, with all its usual external symptoms of swelling, heat, soreness, and the rest of the now-familiar phenomena. The swelling is at first diffused, extending more or less on the exterior part of the hock, and in a few instances running up along the tendons and muscles of the back of the shank. Soon, however, unless the irritating causes are continued and repeated, the edema diminishes, and, becoming more defined in its external outlines, leaves the hock capped with a hygroma. The hygroma, at the very beginning of the trouble, contains a bloody serosity which soon becomes strictly serum, and this, through the influence of an acute inflammatory action, is liable to undergo a change which converts it into the usual purulent product of suppuration.

The external appearance ought to be sufficient to determine the diagnosis, but there are a few signs which may contribute toward a nicer identification of the lesion. The capped hock, whether under the appearance of an acute, edematous swelling, or as a bloody serous collection, or as a simple serous cyst, does not give rise to any remarkable local manifestation other than such as have already passed under our survey in considering similar cases, nor will it be liable to interfere with the functions which belong to the member in question, unless it assumes very large dimensions and on each side of the tendons, as well as on the summit of the bone. But if the inflammation is quite high, if suppuration is developing, if there is a true abscess, or--and this is a common complication--especially when the kicking or rubbing of the animal is frequently recurring, then, besides the local trouble of the cyst or of the abscess, the bones become diseased and the periosteum inflamed; perhaps the superior ends of the bone and its fibro-cartilage become affected, and a simple lesion or bruise, whatever it may have been, becomes complicated with periostitis and ostitis, and is naturally accompanied with lameness, developed in a greater or less degree, which in some cases may be permanent and in others increased by work. These complications, however, are not common or frequent.

Treatment.--Capped hocks are in many cases amenable to treatment, and yet they often become the opprobrium of the practioner by remaining, as they frequently do, an eyesore on the top of the hock; they do not interfere, it is true, with the work of the horse, but fixing upon him the stigma of what, in human estimation, is a most unreliable and objectionable reputation, to wit, that of being an habitual "kicker," and, worse than all, one that kicks when fed.

The maxim that "an ounce of prevention is worth a pound of cure" fits the present case very neatly. A horse whose hocks have a somewhat puffy look and whose skin on the front of the hock is loose and flabby, justly subjects himself to a suspicion of addictedness to this bad habit, but a little watching will soon establish the truth. If, then, the verdict is one of conviction, precautions should be immediately adopted against a continuance of the evil. The padding of the sides of the stall with straw mats or mattresses and covering the posts with similar material, in such manner as to expose no hard surface with which to come in contact, will reduce the evil to its minimum. The animal may jar his frame when he kicks, but even then there will be less force in the concussion than if it impinged upon the solid plank, and cuts and abrasions can not be inflicted by a properly made cushion. Hobbles are also rightly recommended with a view to the required restraint of motion, so applied as to secure the leg with which the kicking is performed, or even both hind legs, in such manner as not to interfere with the movement of lying down and rising again and yet preventing that of kicking backward. Boots similar in pattern to those which are used for the prevention of shoe boil are also prescribed. These are placed above the hock and retained by straps tightly fastened. We apprehend, however, that the difficulty of retaining them in the proper place without the danger of chafing from the tightness of the straps may form an objection to their use. Notwithstanding all precautions, hocks will be capped in the future as in the past, and the study of their treatment will always be in order.

The mode of dealing with them will, of course, be greatly influenced by the condition of the parts. When the inflammation is excessive and the swelling large, hot, and painful to the touch, the application of warm water will be very painful. The leg should be well fomented several times a day, for from 15 to 20 minutes each time, a strong decoction of marsh-mallow leaves being added to the water, and after each application swathed with flannel bandages soaked in the same warm mixture. A few days of this treatment will usually effect a resolution of the inflammation; if not complete, at least sufficiently so to disclose the correct outlines of the hygroma and exhibit its peculiar and specific symptoms. The expediency of its removal and the method of accomplishing it are then to be considered, with the question of opening it to give exit to its contents. If the fluid is of a purulent character, the indication is in favor of its immediate discharge. No time should be lost, and it should be by means of a small opening made with a narrow bistoury. If, however, the fluid is a serosity, we prefer to remove it by punctures with a very small trocar. Our reason for special caution in these cases is our fear of the possibility of the existence of diseased conditions of a severe character in the pseudo joint. For the same reason we prefer the treatment of those growths by external applications. In the first stages of the disease a severe and stiff blister, such as the cantharidate of collodium, entirely covering the cyst, perhaps not yet completely formed, when the inflammation has subsided, will be of great benefit by its stimulating effect, the absorption it may excite, and the pressure which, when dry, it will maintain upon the tumor. If, however, the thickening of the growth fails to diminish, it should be treated with some of the iodin preparations in the form of ointments, pure or in combination with potassium, mercury, etc., of various strengths and in various proportions. My opinion of setons is not favorable, but the actual cautery, by deep and fine firing, in points--needle cauterization--I believe to be the best mode of treatment, and especially when applied early.

A very satisfactory way to treat these cases is to burst the swelling by pressure from without. A strap or strong linen bandage is placed about the hock, pressing on the bursa, while the affected leg is on the ground, the other hind foot being lifted up. When the bandage is in place the leg should be released, and the horse will violently flex the bandaged limb and produce pressure on the bursa, with consequent bursting and discharging of its contents.

Whatever treatment may be adopted for capped hock, patience must be one of the ingredients. In these parts absorption is slow, the skin is very thick, and its return to a soft, pliable, natural condition, if effected at all, will take place only after weeks added to other weeks of medical treatment and patient waiting.

INTERFERING, AND SPEEDY CUTS.

These designations belong to certain special injuries of the extremities, produced by similar causes, giving rise to kindred pathological lesions with allied phenomena, requiring about the same treatment and often followed by the same results, to wit, a blemish which may not only subject the animal to a suspicion of unsoundness, but in some special circumstances may interfere with his ability to labor. It is known as "interfering" when the location of the trouble is the inside of the fetlock of either the fore or hind leg. It is called "speedy cut" when it occurs on the inside of the fore leg, a little below the knee, at the point of contact of that joint with the cannon. It is always the result of a blow, self-inflicted, of varying severity, and giving rise to various lesions. (See also p. 399.)

Symptoms.--At times the injury is too slight to be seriously noticed, the hair being scarcely cut and the skin unmarked. At other times the skin will be cut through, partly or wholly, and it may for the time cause sufficient pain to check the motion of the animal and induce him to suspend his labor through his inability to use the wounded limb, traveling meanwhile for a short space on three legs only. Sometimes a single blow will suffice, or again there will be a repetition of lighter strokes. In the latter case the parts will become much swollen, hot, and so painful to the touch that the motion of the knee or the fetlock will be sufficiently disturbed to cause lameness of a degree of severity corresponding to that of the lesion. Following the subsidence of this diffused and edematous swelling is sometimes the formation of a tumor, either at the knee or the fetlock. This may be soft at first or become so by degrees, with fluctuation, its contents being at first extravasated blood, and later a serosity; or, if there has been a sufficient degree of inflammation, it may become suppurative. The result of the fault of interfering may thus be exhibited, whether at the knee or at the fetlock, as characterized by all the pathological conditions which have appeared as accompaniments of capped knee or capped hock. If, in consequence of the force of the blow or blows, the inflammation has been usually severe, a mortification of the skin may become one of the consequences, a slough taking-place, succeeded by a cutaneous ulcer on the inside of the fetlock or when the greater number of the original wounds are inflicted. If the interfering has been often repeated it may be followed by another condition, which has been considered in our remarks upon other affections. It is a plastic exudation or thickening of the parts, which are commonly said to have become "callous," and the effect of it is to destroy the regularity of the outlines of the joint to an extent which constitutes a serious blemish, which will be permanent, and according to the degree of the aberration from the natural and symmetrical lines will inevitably depreciate the commercial value of the animal.

An animal in interfering may thus exhibit a range of symptoms which from the simplest form of a mere "touching," may successively assume the serious characters of an ugly cicatrix, a hard, plastic swelling, or perhaps, as witnessed at the knee, of periostitis with its sequelae.

If a single and constantly recurring cause--a blow--is the starting point in interfering, we may now consider the subject of the predisposition which brings such serious results upon the suffering animal, and the conditions which lead to and accompany it. These are numerous, but the first in frequency and importance is peculiarity of conformation in the animals addicted to it. The first class will include horses, whose chests are narrow and whose legs do not stand straight and upright, but are crooked and pigeon-toed in and out. The second class includes those whose legs are weak, either from youth or hard labor, or from severe attacks of sickness. Another class is made up of those having abnormally developed feet, or which have been badly shod with unnecessarily wide or heavy shoes. Another class consists of those that are affected with swollen fetlocks or chronic, edematous swelling of the leg. Another is formed of animals with a peculiar action, as those whose knee action is very high, and it is these that furnish most of the cases of speedy cut.

Prognosis.--The prognosis of interfering is never a very serious one. However violent the blow may be it is rarely that subsequent complications of a troublesome nature occur. The principal evil attending it is a liability to be followed by a thickened or callous deposit which is not only an eyesore and a blemish, but constitutes a new and increased predisposition. The remark that "an animal which has interfered once is always liable to interfere," is often confirmed and sanctioned by a recurrence of the trouble.

Treatment.--Another point in which there is a resemblance between this lesion and others which we have considered is in its responsiveness to the same treatment with them. Indeed, the prescription of warm fomentations, soothing applications, and astringent and resolvent mixtures, in a majority of cases, is the first that occurs all through the list. If the swelling assumes the character of a serous collection, pressure, cold water, and bandages will contribute to its removal. If suppuration seems to be established and the swelling assumes the character of a developing abscess, hot poultices of flaxseed or of boiled vegetables and the embrocations of sedative ointments, those of basilicon, or vaseline, impregnated with preparations of opium or belladonna--all these recommend themselves by their general adaptation and the beneficial results which have followed their administration, not less in one case than in another. When an abscess has formed and is fluctuating, it should be carefully but fully opened to evacuate the pus. If it is a serous cyst, some care is necessary in emptying it, and the possibility of the extension of the inflammation to the joint must be taken into consideration. When the cavities have been emptied and have closed by filling up with granulations, or if, not being opened, the contents have been reabsorbed, and there remains in either case a plastic exudation and a tendency to the callous organization that may yet exist, blisters under their various forms, including those of cantharides, of mercury, and of iodin, are then indicated, principally in the early stages, as it is then that their effects will prove most satisfactory. The use of the actual cautery, with fine points, penetrating deeply throughout the enlargement, has in our hands, when used in the very early stages of its formation, nearly always brought on a radical recovery with complete absorption of the thickening.

STRINGHALT.

This is an involuntary movement of one or both hind legs, in which the foot is suddenly and spasmodically lifted from the ground much higher than it is normally carried, with excessive flexion of one bone upon the other. This peculiarity is usually prominent, although it may disappear with work, only to reappear after a short rest. Sometimes it is most apparent at a trot, sometimes at a walk, and other times only when turned around; or it may not be affected by the gait of the horse. It does not seem to be influenced by the horse's age, young and old being alike affected. Its first manifestations are sometimes very slight. It has been noticed as occurring in an animal when backing out of his stable and ceasing immediately after. In some animals it is best seen when the animal is turning around on the affected leg, and it is not noticed when he moves straight forward. That this peculiar action interferes with facility of locomotion and detracts from a horse's claim to soundness can not for a moment be denied.

Cause.--Veterinarians and pathologists are yet in doubt in respect to the cause of this affection, as well as to its essential nature. Whether it results from disease of the hock, of an ulcerative character; whether it springs from a malformation; whether it is a shortening of the ligaments, a chronic inflammation of the sciatic nerve, or a disease of the spinal cord; whether it is purely a muscular or purely a nervous lesion, or a compound of both--it still continues, if an etiologist is bound to possess universal knowledge within the scope of his special studies, to be his reproach and his puzzle.

Treatment.--When there is a known or suspected cause the treatment should be directed toward this factor. If due to local inflammation of the hock or foot, only this local lesion should be treated. If it remains after the local lesion has healed, or if we have no assignable cause, the best results have followed the sectioning of the lateral extensor of the foot. A competent veterinarian alone should undertake this operation.

THROMBOSIS.

There are certain forms of lameness which are very peculiar in their manifestation, and which to the nonprofessional mind must appear to belong to the domain of mystery or theory instead of occupying a well-established position among the subjects of equine pathology. Yet they are no less susceptible of actual demonstration and of positive comprehension than many facts which, plain and familiar to the general understanding now, were once ranked among things occult and unsearchable. A thrombus, considered as a cause of lameness, may find a place among these understood mysteries.

Cause.--Under certain peculiar conditions of inflammation of the blood vessels, and also in aneurisms, clots of blood are sometimes formed in the arteries and find their way in the general circulation. At first, while very small, or sufficiently so to pass from one vessel to another, they move from a small vessel to a larger, and from that to one still larger, constantly increasing in size until at some given point, from their inability to enter smaller vessels, their movement is finally arrested. The artery is thus effectually dammed, and the clot in a short time cuts off completely the supply of blood from the parts beyond. This is thrombosis, and it often gives rise to sudden and excessive lameness of a very painful character.

Symptoms.--Thrombi may form in any of the arteries, and doubtless have been the cause of many cases of lameness which could never be accounted for. If they exist in small arteries their diagnosis will probably fail to be made out with certainty, but when situated in the larger trunks a strong suspicion of their presence may be excited. In some cases they may even be recognized with positive accuracy, as when the vessels which supply the posterior extremities are affected by the blocking up of the posterior aorta or its ramifications.

The existence of thrombosis of the arteries of the hind leg may always be suspected when the following history is known: The general health of the animal is good, but symptoms of lameness in one of the legs have been developed, becoming more marked as he is worked, and especially when driven at a fast gait. But the disturbance is not permanent, and the lameness disappears almost immediately after a rest. There is an increase of the difficulty, however, and, though the animal may walk normally, he will, when made to trot, very soon begin to slacken his pace and to show signs of the trouble, and if urged to increase his speed will become lamer and lamer; an abundant perspiration will break out; he will refuse to go, and if forced he shows weakness behind, seems ready to fall, and perhaps does fall. While on his feet the leg is kept in constant motion, up and down, and is kept from the ground as if the contact were too painful to bear. If undisturbed this series of symptoms will gradually subside, sometimes very soon, and occasionally after a few hours he will return to an apparently perfect condition. A return to labor will lead to a renewal of the same incidents.

A history like this suggests a strong suspicion of a thrombus in an artery of the hind leg, and this suspicion will be confirmed by the external symptoms exhibited by the animal. The total absence of any other disease which might account for the lameness, and a manifest diminution of heat over a part or the whole of the extremity, when compared with the opposite side or with any other portion of the body; a sensation of cold attendant on the pain, but gradually subsiding as the pain subsides, and the circulation, quickened by the rest, has been reestablished throughout the extremity; all these are confirmatory circumstances. Still, it is thus far only a suspicion, and absolute certainty is yet wanting. To establish the truth of the case the rectal exploration must be resorted to. The hands then, well prepared and carefully introduced into the rectum, must explore for the truth, first feeling for the large blood vessels which, divided at the aorta, separate to supply the right and left legs. These must be compared in respect to the pulsation and other particulars. The artery which is healthy will, of course, exhibit all the proper conditions of that state. On the other hand, if the vessel appears to the feel hard, more or less cordy, and pulseless, or giving a sensation of fluttering, as of a small volume of blood with a trickling motion passing through a confined space, the difference between the sides will make the case plain. The first will be the full flow of the circulation through an unobstructed channel, the other a forced passage of the fluid between the thrombus and the coats of the artery. In such case the prognosis is necessarily a grave one and the disease is more liable to grow Worse than better.

Treatment.--No form of treatment can be advised; the suffering or a helpless and useless animal can only be terminated by that which ends all.

Cases occur, however, where this condition of the blood vessels exists in a much less degree, and the diseased condition is not sufficiently pronounced for final condemnation. There may even be a possibility of the absorption of the clot, or that an increase of the collateral circulation may be sufficient to supply the parts with blood. In such cases spontaneous recovery may follow moderate exercise in the pasture, field, or stable, or continuous light work may be given, but too much hope should not be placed in such treatment.

SPRAINS OF THE LOINS.

This is an affection which suggests to the mind the idea of muscular injury, and is difficult to distinguish from many similar cases. If the animal shrinks from the slightest pressure or pinching of the spine in the region of the loins, he is by many pronounced to be "lame in the loins," or "sprained in the loins," or "weak in the kidneys." This is a grave error, as in fact this simple and gentle yielding to such a pressure is not a pathological sign, but is normal and significant of health. Yet there are several conditions to which the definition of "sprains of the loins" may apply which are not strictly normal.

Cause.--The muscles of the back and those of the loins proper, as the psoas, may have been injured, or again there may be trouble of a rheumatic nature, perhaps suggestive of lumbago. Diseases of the bones of the vertebral column, or even those of the organs of circulation, may give rise to an exhibition of similar symptoms.

Symptoms.--The symptoms are characteristic of a loss of rigidity or firmness of the vertebral column, both when the animal is at rest and in action. In the former condition, or when at rest, there is an arched condition of the back and a constrained posture in standing, with the hind legs separated. In the latter there is a lateral, balancing movement at the loins, principally noticeable while the animal is in the act of trotting--a peculiar motion, sometimes referred to as a "crick in the back," or what the French call a "tour de bateau." If, while in action, the animal is suddenly made to halt, the act is accompanied with much pain, the back suddenly arching or bending laterally, and perhaps the hind legs thrown under the body, as if unable to perform their functions in stopping, and sometimes it is only accomplished at the cost of a sudden and severe fall. This manifestation is also exhibited when the animal is called upon to back, when a repetition of the same symptoms will also occur.

If a slight pressure on the back or the loins is followed by a moderate yielding of the animal, it is, as before remarked, a good sign of health. With a sprain of the loins pressure of any kind is painful, and will cause the animal to bend or to crouch under it more or less, according to the weight of the pressure. Heavy loads, and even heavy harnessing, will develop this tenderness. In lying down he seems to suffer much discomfort, and often accompanies the act with groaning, and when compelled to rise does so only with great difficulty and seldom succeeds without repeated efforts.

Sprains of muscles proper, when recent, will always be accompanied with this series of symptoms, and the fact of their exhibition, with an excessive sensibility of the parts, and possibly with a degree of swelling, will always justify a diagnosis of acute muscular lesion, and especially so if accompanied with a history of violent efforts, powerful muscular strains, falls, heavy loading, etc., connected with the case. If the symptoms have been of slow development and gradual increase, it becomes a more difficult task to determine whether the diagnosis points to pathological changes in the structure of the muscles or of the bones, the nervous centers, or the blood vessels of the region. And yet it is important to decide as to which particular structure is affected in reference to the question of prognosis, as the degree of gravity of the lesion will depend largely upon whether the disabled condition of the animal is due to an acute or a chronic disease.

Treatment.--The prescription which will necessarily first of all suggest itself for sprains of the loins is rest. An animal so affected should be immediately placed in slings, and none of his efforts to release himself should be allowed to succeed. Hot compresses, cold-water douches, sweating applications, stimulating frictions, strengthening charges, blistering ointments of cantharides and the actual cautery, all have their advocates, but in no case can the immobility obtained by the slings be dispensed with. In many cases in which the weakness of the hind quarters was caused by disease of the nervous centers electricity has also yielded good results.

FOOTNOTES:

[2] This bandage consists of a cloth drenched in warm water or a dripping bandage laid around the diseased part, then covered by several layers of woolen blanket or cloth, which is in turn covered by parchment paper, rubber cloth, or other impervious material. Heat, moisture, and pressure are obtained by such a bandage if water is poured upon it several times daily.

DISEASES OF THE FETLOCK, ANKLE, AND FOOT.

By A. A. HOLCOMBE, D. V. S.,

Veterinary Inspector, Bureau of Animal Industry.

ANATOMICAL REVIEW OF THE FOOT.

In a description of the foot of the horse it is customary to include only the hoof and its contents, yet, from a zoological standpoint, the foot includes all the leg from the knee and the hock down.

The foot of the horse is undoubtedly the most important part of the animal, so far as veterinary surgery is concerned, for the reason that it is subject to so many injuries and diseases which in part or in whole render the patient unfit for the labor demanded of him. The old aphorism "no foot no horse" is as true to-day as when first expressed; in fact, domestication, coupled with the multiplied uses to which the animal is put, and the constant reproduction of hereditary defects and tendencies, has largely transformed the ancient "companion of the wind" into a very common piece of machinery which is often out of repair, and at best is but shortlived in its usefulness.

Since the value of the horse depends largely or even entirely upon his ability to labor, it is essential that his organs of locomotion be kept sound. To accomplish this end it is necessary not only to know how to cure all diseases to which these organs are liable but, better still, how to prevent them.

An important prerequisite to the detection and cure of disease is a knowledge of the construction and function of the parts which may be involved in the diseased process. Hence, first of all, the anatomical structures must be understood. (See also p. 583.)

The bones of the fetlock and foot constitute the skeleton on which the other structures are built and comprise the lower end of the cannon bone (the metacarpus in the fore leg, the metatarsus in the hind leg), the two sesamoids, the large pastern or os suffraginis, the small pastern or coronet, the small sesamoid or navicular bone, and the coffin bone or os pedis. (Plate XXXIV, fig. 3.)

The cannon bone extends from the knee or hock to the fetlock, is cylindrical in shape, and stands nearly or quite perpendicular.

The sesamoids occur in pairs, are small, shaped like a three-faced pyramid, and are set behind the fetlock joint, at the upper end of the large pastern, with the base of the pyramid down.

The large pastern is a very compact bone, set in an oblique direction downward and forward, and extends from the cannon bone to the coronet.

The coronet is a short, cube-shaped bone, set between the large pastern and coffin bone, in the same oblique direction.

The navicular bone is short, flattened above and below, and is attached to the coffin bone behind.

The coffin bone forms the end of the foot and is shaped like the horny box in which it is inclosed.

All these bones are covered on the surfaces which go to make up the joints with a cartilage of incrustation, while the portions between are covered with a fibrous membrane called the periosteum.

The joints of the legs are of especial importance, since any interference with their function very largely impairs the value of the animal for most purposes. As the joints of the foot and ankle are at the point of greatest concussion they are the ones most subject to injury and disease.

There are three of these joints--the fetlock, pastern, and coffin. They are made by the union of two or more bones, held together by ligaments of fibrous tissue, and are lubricated by a thick, viscid fluid, called synovia, which is secreted by a special membrane inclosing the joints.

The fetlock joint is made by the union of the lower end of the cannon and the upper end of the large pastern bones, supplemented by the two sesamoids, so placed behind the upper end of the pastern that the joint is capable of a very extensive motion. These bones are held together by ligaments, only one of which--the suspensory--demands special mention.

The suspensory ligament of the fetlock starts from the knee, extends down behind the cannon, lying behind the two splint bones, until near the fetlock, where it divides and sends a branch on each side of the joint, downward and forward, to become attached on the sides of the extensor tendon at the lower end of the pastern bone. As it crosses the sesamoids, on the posterior borders of the fetlock, it throws out fibers which hold it fast to these bones. (Plate XXXIV, fig. 2.)

The pastern joint is made by the union of the two pastern bones.

The coffin joint is made by the union of the small pastern, coffin, and small sesamoid, or navicular bones, the latter being set behind and beneath the joint surface of the coffin bone in such way as to receive largely the weight of the small pastern.

Three tendons serve to move the bones of the foot one on another. Two of these flex, or bend, the joints, while the other extends, or straightens, the column of bones. (Plate XXXIII, fig. 5.)

The flexor pedis perforans, or deep flexor of the foot, passes down behind the cannon bone, lying against the suspensory ligament in front, crosses the fetlock joint in the groove made by the union of the two sesamoids, and is attached to the bottom on the coffin bone, after covering the navicular, by a wide expansion of its fibers. It is the function of this tendon to flex the coffin bone and, with it, the horny box.

The flexor pedis perforatus, or superficial flexor of the foot, follows the course of the preceding tendon and is attached to the middle of the ankle. The function of this tendon is to flex the foot at the fetlock.

The extensor pedis runs down in front of the leg, is attached on the most prominent point of the coffin bone, and has for function the straightening of the bones of the ankle and foot.

The bones, ligaments, and tendons are covered by a loose connective tissue, which gives a symmetry to the parts by filling up and rounding off, and all are protected by the skin and hoof.

The skin of the fetlock and ankle is generally characterized by its thickness and the length of its hairs, especially around the hind parts of the fetlock joint in certain breeds of horses. The most important part of this envelope is that known as the coronary band.

The coronary band is that portion of the skin which secretes the horn of which the wall of the hoof is made. This horn much resembles the nail which grows on the fingers and toes of man. It is composed of cylindrical tubes, which are held together by a tenacious, opaque matter. The horn extends from the coronary band to the lower border of the hoof. (Plate XXXII, fig. 1.)

The hoof is a box of horn, consisting of a wall, sole, and frog, and contains, besides the coffin, navicular, and part of the small pastern bones, the sensitive laminae, plantar cushion, and the lateral cartilages. (Plate XXXIII, fig. 4.)

The sole of the foot incloses the box on the ground surface, is shaped like the circumference of the foot, except that a V-shaped opening is left behind for the reception of the frog, and is concave on the lower surface. The sole is produced by the velvety tissue, a thin membrane covering the plantar cushion and other soft tissues beneath the coffin bone. The horn of the sole differs from the horn of the wall in that its tubes are not straight and from the fact that it scales off in pieces over the whole surface.

The frog is a triangular-shaped body, divided into two equal parts by a deep fissure, extending from its apex in front to the base. It fills the triangular space in the sole, to which it is intimately attached by its borders. The horn of the frog is produced in the same manner as the sole; but it differs from both the wall and sole in that the horn is soft, moist, and elastic to a remarkable degree. It is the function of the frog to destroy shock and to prevent slipping.

The sensitive laminae are thin plates of soft tissue covering the entire anterior surface of the coffin bone. They are present in great numbers, and by fitting into corresponding grooves on the inner surface of the horn of the wall the union of the soft and horny tissues is made complete. (Plate XXXII, fig. 1.)

The plantar cushion is a thick pad of fibrous tissue placed behind and under the navicular and coffin bones and resting on the sole and frog, for the purpose of receiving the downward pressure of the column of bones and to destroy shock. (Plate XXXII, fig. 4.)

The lateral cartilages are attached, one on each side, to the wings of the coffin bone by their inferior borders. They are thin plates of fibro-cartilage, and their function is to assist the frog and adjacent structures to regain their proper position after having been displaced by the weight of the body while the foot rested on the ground. (Plate XXXII, fig. 2.)

FAULTS OF CONFORMATION.

A large percentage of horses have feet which are not perfect in conformation, and as a consequence they are especially predisposed to certain injuries and diseases.

Flatfoot is that condition in which the sole has little or no convexity. It is a peculiarity common to some breeds, especially heavy, lymphatic animals raised on low, marshy soils. It is confined to the fore feet, which are generally broad, low-heeled, and with a wall less upright than is seen in the perfect foot.

In flatfoot there can be little or no elasticity in the sole, for the reason that it has no arch, and the weight of the animal is received on he entire plantar surface, as it rests upon the ground instead of on the wall. For these reasons such feet are particularly liable to bruises of the sole, corns, pumiced sole, and excessive suppuration when the process is once established. Horses with flatfoot should be shod with a shoe having a wide web, pressing on the wall only, while the heels and frog are never to be pared. Flatfoot generally has weak walls, and as a consequence the nails of the shoe are readily loosened and the shoe cast.

Clubfoot is a term applied to such feet as have the walls set nearly perpendicular. When this condition is present the heels are high, the fetlock joint is thrown forward, or knuckles, and the weight of the animal is received on the toes. Many mules are clubfooted, especially behind, where it seems to cause little or no inconvenience. Severe cases of clubfoot may be cured by cutting the tendons, but as a rule special shoeing is the only measure of relief that can be adopted. The toe should not be pared, but the heels are to be lowered as much as possible and a shoe put on with a long, projecting toe piece, slightly turned up, while the heels of the shoe are to be made thin.

Crookedfoot is that condition in which one side of the wall is higher than the other. If the inside wall is the higher, the ankle is thrown outward, so that the fetlock joints are abnormally wide apart and the toes close together. Animals with this deformity are "pigeon-toed," and are prone to interfere, the inside toe striking the opposite fetlock. If but one foot is affected, the liability to interfere is still greater, for the reason that the fetlock of the perfect leg is nearer the center plane.

When the outside heel is the higher the ankle is thrown in and the toe turns out. Horses with such feet interfere with the heel. If but one foot is so affected, the liability to interfere is less than when both feet are affected, for the reason that the ankle of the perfect leg is not so near to the center plane. Such animals are especially liable to stumbling and to lameness from injury to the ligaments of the fetlock joints. This deformity is to be overcome by such shoeing as will equalize the disparity in length of walls, and by proper boots to protect the fetlocks from interfering.

INTERFERING.

An animal is said to interfere when one foot strikes the opposite leg, as it passes by, during locomotion. The inner surface of the fetlock joint is the part most subject to this injury, although, under certain conditions, it may happen to any part of the ankle. It is seen more often in the hind than in the fore legs. Interfering causes a bruise of the skin and deeper tissues, generally accompanied with an abrasion of the surface. It may cause lameness, dangerous tripping, and thickening of the injured parts. (See also p. 387.)

Causes.--Faulty conformation is the most prolific cause of interfering. When the bones of the leg are so united that the toe of the foot turns in (pigeon-toed), or when the fetlock joints are close together and the toe turns out, when the leg is so deformed that the whole foot and ankle turn either in or out, interfering is almost sure to follow. It may happen, also, when the feet grow too long, from defective shoeing, rough or slippery roads, from the exhaustion of labor or sickness, swelling of the leg, high knee action, fast work, and because the chest or hips are too narrow.

Symptoms.--Generally, the evidences of interfering are easily detected, for the parts are tender, swollen, and the skin broken. But very often, especially in trotters, the flat surface of the hoof strikes the fetlock without evident injury, and attention is directed to these parts only by the occasional tripping and unsteady gait. In such cases proof of the cause may be had by walking and trotting the animal, after first painting the inside toe and quarter of the suspected foot with a thin coating of chalk, charcoal, mud, or paint.

Treatment.--When the trouble is due to deformity or faulty conformation it may not be possible to overcome the defect.

In such cases, and as well in those due to exhaustion or fatigue, the fetlock or ankle boot must be used. In many instances interfering may be prevented by proper shoeing. The outside heel and quarter of the foot on the injured leg should be lowered sufficiently to change the relative position of the fetlock joint by bringing it farther away from the center plane of the body, thereby permitting the other foot to pass by without striking.

A very slight change is often sufficient to effect this result. At the same time the offending foot should be so shod that the shoe may set well under the hoof at the point responsible for the injury. The shoe should be reset every three or four weeks.

When the cause has been removed, cold-water bandages to the injured parts will soon remove the soreness and swelling, especially in recent cases. If, however, the fetlock has become calloused from long-continued bruising, a Spanish-fly blister over the parts, repeated in two or three weeks if necessary, will aid in reducing the leg to its natural condition.

KNUCKLING, OR COCKED ANKLES.

Knuckling is a partial dislocation of the fetlock joint, in which the relative position of the pastern bone to the cannon and coronet bones is changed, the pastern becoming more nearly perpendicular, with the lower end of the cannon bone resting behind the center line of the large pastern, while the lower end of this bone rests behind the center line of the coronet. While knuckling is not always an unsoundness, it nevertheless predisposes to stumbling and to fracture of the pastern.

Causes.--Young foals are quite subject to this condition, but in the great majority of cases it is only temporary. It is largely due to the fact that before birth the legs were flexed, and time is required after birth for the ligaments, tendons, and muscles to adapt themselves to the function of sustaining the weight of the body.

As they grow old, horses with erect pasterns are very prone to knuckle, especially in the hind legs. All kinds of heavy work, particularly in hilly districts, and fast work on hard race tracks or roads are exciting causes of knuckling. It is also commonly seen as an accompaniment of that faulty conformation called clubfoot, in which the toe of the wall is perpendicular and short, and the heels high--a condition most often seen in the mule, especially in the hind feet.

Lastly, knuckling is produced by disease of the suspensory ligament or of the flexor tendons, whereby they are shortened, and by disease of the fetlock joints. (See p. 372.)

Treatment.--In young foals no treatment is necessary, unless there is some deformity present, since the legs straighten up without interference in the course of a few weeks. When knuckling has commenced, the indications are to relieve the tendons and ligaments by proper shoeing. The foot is to be prepared for the shoe by shortening the toe as much as possible, leaving the heels high; or if the foot is prepared in the usual way the shoe should be thin in front, with thick heels or high calks. For the hind feet a long-heeled shoe with calks seems to do best. Of course, when possible, the causes of knuckling are to be removed; since this can not always be done, however, the time may come when the patient can no longer perform any service, particularly in those cases in which both fore legs are affected, and it becomes necessary either to destroy the animal or obtain relief by surgical interference. In such cases the tendons between the fetlock and knee may be divided for the purpose of obtaining temporary relief. Firing and blistering the parts responsible for the knuckling may, in some instances, effect a cure; but a consideration of these measures belongs properly to the treatment of the disease in which knuckling appears simply as a sequel.

WINDGALL.

Joints and tendons are furnished with sacs containing a lubricating fluid called synovia. When these sacs are overdistended by reason of an excessive secretion of synovia, they are called windgalls. They form a soft, puffy tumor about the size of a hickory nut, and are most often found in the fore leg, at the upper part of the fetlock joint, between the tendon and the shin bone. When they develop in the hind leg it is not unusual to see them reach the size of a walnut. Occasionally they appear in front of the fetlock on the border of the tendon. The majority of horses are not subject to them after colt-hood has passed. (See also p. 355.)

Causes.--Windgalls are often seen in young, overgrown horses, in which the body seems to have outgrown the ability of the joints to sustain the weight. In cart and other horses used to hard work, in trotters with excessive knee action, in hurdle racers and hunters, and in most cow ponies there is a predisposition to windgalls. Street-car horses and others used to start heavy loads on slippery streets are the ones most liable to develop windgalls in the hind legs.

Symptoms.--The tumor is more or less firm and tense when the foot is on the ground, but is soft and compressible when the foot is off the ground. In old horses windgalls generally develop slowly and cause no inconvenience. If they are caused by excessive tension of the joint the tumor develops rapidly, is tense, hot, and painful, and the animal is exceedingly lame. The patient stands with the joint flexed, and walks with short steps, the toe only being placed on the ground. When the tumor is large and situated upon the inside of the leg it may be injured by interfering, causing stumbling and inflammation of the sac. Rest generally causes the tumor to diminish in size, only to fill up again after renewed labor. In old cases the tumors are hardened, and may become converted into bone by a deposit of the lime salts.

Treatment.--The large, puffy joints of suckling colts, as a rule, require no treatment, for as the animal grows older the parts clean up and after a time the swelling entirely disappears.

When the trouble is from an injury, complete rest is to be obtained by the use of slings and a high-heeled shoe. Cold-water douches should be used once or twice a day, followed by cold-water bandages, until the fever has subsided and the soreness is largely removed, when a blister is to be applied.

In old windgalls, which cause more or less stiffness, some relief may be had by the use of cold-compress bandages, elastic boots, or the red iodid of mercury blisters. Opening the sacs, as recommended by some authors, is of doubtful utility, and should be adopted only by the surgeon capable of treating the wound he has made. Enforced rest until complete recovery is effected should always be insisted upon, since a too early return to work is sure to be followed by relapse.

SPRAIN OF THE FETLOCK.

Sprain of the fetlock joint is most common in the fore legs, and, as a rule, affects but one at a time. Horses doing fast work, as trotters, runners, steeplechasers, hunters, cow ponies, and those that interfere, are particularly liable to this injury.

Causes.--Horses knuckling at the fetlock, and all those with diseases which impair the powers of locomotion, such as navicular disease, contracted heels, sidebones, chronic laminitis, etc., are predisposed to sprains of the fetlock. It generally happens from a misstep, stumbling, or slipping, which results in the joint being extended or flexed to excess. The same result may happen where the foot is caught in a rut, a hole in a bridge, or in a car track, and the animal falls or struggles violently. Direct blows and punctured wounds may also set up inflammation of the joint.

Symptoms.--The symptoms of sprain of the fetlock vary with the severity of the injury. If slight, there may be no lameness, but simply a little soreness, especially when the foot strikes on uneven ground and the joint is twisted a little. In more severe cases the joint swells, is hot and puffy, and the lameness may be so intense as to compel the animal to hobble on three legs. While at rest the leg is flexed at the joint affected, and the toe rests on the ground.

Treatment.--If the injury is slight, cold-water bandages and a few days' rest are sufficient to effect recovery. When there is an intense lameness, swelling, etc., the leg should be placed under a constant stream of cold water, as described in the treatment for quittor. When the inflammation has subsided, a blister to the joint should be applied.

In some cases, especially in old horses long accustomed to fast work, the ligaments of the joints are ruptured, in whole or in part, and the lameness may last a long time. In these cases the joint should be kept completely at rest; this condition is best obtained by the application of plaster of Paris bandages, as in cases of fracture. As a rule, patients take kindly to this bandage, and, while wearing it, may be given the freedom of a roomy box or yard. If they are disposed to tear it off, or if sufficient rest can not otherwise be obtained, the patient must be kept in slings.

In the majority of instances the plaster bandage should remain on from two to four weeks. If the lameness returns when the bandage is removed, a new one should be put on. The swellings which always remains after the other evidences of the disease have disappeared, may be largely dissipated and the joint strengthened by the rise of the firing iron and blisters.

A joint once injured by a severe sprain never entirely regains its original strength, and is ever after particularly liable to a repetition of the injury.

RUPTURE OF THE SUSPENSORY LIGAMENT.

Sprain with or without rupture of the suspensory ligament may happen in either the fore or hind legs, and is occasionally seen in horses of all classes and at all ages. Old animals, however, and especially hunters, runners, and trotters, are the most subject to this injury, and with them the seat of the trouble is nearly always in one or both the fore legs. Horses used for heavy draft are more liable to have the ligament of the hind legs affected.

When the strain upon the suspensory ligament becomes too great, one or both of the branches may be torn from the sesamoid bones, one or both of the branches may be torn completely across, or the ligament may rupture above the point of division.

Symptoms.--The most common injury to the suspensory ligament is sprain of the internal branch in one of the fore legs. The trouble is indicated by lameness, heat, swelling, and tenderness of the affected branch, beginning just above the sesamoid bone and extending obliquely downward and forward to the front of the ankle. If the whole ligament is involved, the swelling comes on gradually, and is found above the fetlock and in front of the flexor tendons. The patient stands or walks upon the toe as much as possible, keeping the fetlock joint flexed so as to relieve the ligament of tension.

When both branches are torn from their attachments to the sesamoids, or both are torn across, the lameness comes on suddenly and is most intense; the fetlock descends, the toe turns up, and, as the animal attempts to walk, the leg has the appearance of being broken off at the fetlock. These symptoms, followed by heat, pain, and swelling of the parts at the point of injury, will enable anyone to make a diagnosis.

Treatment.--Sprain of the suspensory ligament, no matter how mild it may be, should always be treated by enforced rest of at least a month, and the application of cold douches and cold-water bandages, firmly applied until the fever has subsided, when a cantharides blister should be put on and repeated in two or three weeks if necessary. When rupture has taken place the patient should be put into slings and a constant stream of cold water allowed to trickle over the seat of injury until the fever is reduced. In the course of a week or ten days a plaster of Paris splint, such as is used in fractures, is to be applied and left on for a month or six weeks. When this is taken off, blisters may be used to remove the remaining soreness; but it is useless to expect a removal of all the thickening, for, in the process of repair, new tissue has been formed which will always remain.

In old cases of sprain the firing iron may often be used with good results. As a rule, severe injuries to the suspensory ligament incapacitate the subject for anything but slow, light work.

OVERREACH.

When the shoe of the hind foot strikes and injures the heel or quarter of the forefoot the horse is said to overreach. It rarely happens except when the animal is going fast; hence is most common in trotting and running horses. In trotters the accident generally happens when the animal breaks from a trot to a run. The outside heels and quarters are most liable to the injury.

Symptoms.--The coronet at the heel or quarter is bruised or cut, the injury in some instances involving the horn as well. When the hind foot strikes well back on the heel of the fore foot--an accident known among horsemen as "grabbing"--the shoe may be torn from the forefoot or the animal may fall to its knees. Horses accustomed to overreaching are often "bad breakers," for the reason that the pain of the injury so excites them that they can not readily be brought back to the trotting gait.

Treatment.--If the injury is but a slight bruise, cold-water bandages applied for a few days will remove all the soreness. If the parts are deeply cut, more or less suppuration will follow, and, as a rule, it is well to poultice the parts for a day or two, after which cold baths may be used, or the wounds dressed with tincture of aloes, oakum, and a roller bandage.

When an animal is known to be subject to overreaching, he should never be driven fast without quarter boots, which are specially made for the protection of the heels and quarters.

If there is a disposition to "grab" the forward shoes, the trouble may be remedied by having the heels of these shoes made as short as possible, while the toe of the hind foot should project well over the shoe. When circumstances permit of their use, the fore feet may be shod with the "tips" instead of the common shoe, as described in treatment for contracted heels.

CALK WOUNDS.

Horses wearing shoes with sharp calks are liable to wounds of the coronary region, either from trampling on themselves or on each other. These injuries are most common in heavy draft horses, especially on rough roads and slippery streets. The fore feet are more liable than the hind ones, and the seat of injury is commonly on the quarters. In the hind feet the wound often results from the animal resting with the heel of one foot set directly over the front of the other. In these cases the injury is generally close to the horn, and often involves the coronary band, the sensitive laminae, the extensor tendon, and even the coffin bone.

Treatment.--Preventive measures include the use of boots to protect the coronet of the hind foot and of a blunt calk on the outside heel of the fore shoe, since this is generally the offending instrument when the fore feet are injured. If the wound is not deep and the soreness slight, cold-water bandages and a light protective dressing, such as carbolized cosmoline, will be all that is needed. When the injury is deep, followed by inflammation and suppuration of the coronary band, lateral cartilages, sensitive laminae, etc., active measures must be resorted to. Cold, astringent baths, made by adding 2 ounces of sulphate of iron to 1 gallon of water, should be used, followed by poultices, if it is necessary to hasten the cleansing of the wound by stimulating the sloughing process. If the wound is deep between the horn and the skin, especially over the anterior tendon, the horn should be cut away so that the injured tissues may be exposed. The subsequent treatment in these cases should follow the directions given in the article on toe cracks.

FROSTBITES.

Excepting the ears, the feet and legs are about the only parts of the horse liable to become frostbitten. The cases most commonly seen are found in cities, especially among car horses, where salt is used for the purpose of melting the snow on curves and switches. This mixture of snow and salt is splashed over the feet and legs, rapidly lowering the temperature of the parts to the freezing point. In mountainous districts, where the snowfall is heavy and the cold often intense, frostbites are not uncommon, even among animals running at large.

Symptoms.--When the frosting is slight the skin becomes pale and bloodless, followed soon after by intense redness, heat, pain, and swelling. In these cases the hair may fall out and the epidermis peel off, but the inflammation soon subsides, the swelling disappears, and only an increased sensitiveness to cold remains.

In more severe cases irregular patches of skin are destroyed and after a few days slough away, leaving slow-healing ulcers behind. If produced by low temperatures and deep snow, the coronary band is the part most often affected.

In many instances there is no destruction of the skin, but simply a temporary suspension of the horn-producing function of the coronary band. The fore feet are more often affected than the hind ones, and the heels and quarters are less often involved than the front part of the foot. The coronary band becomes hot, swollen, and painful, and after two or three days the horn separates from the band and slight suppuration follows. For a few days the animal is lame, but as the suppuration disappears the lameness subsides. New horn, often of an inferior quality, is produced by the coronary band, and in time the cleft is grown off and complete recovery is effected. The frog is occasionally frostbitten and may slough off, exposing the soft tissues beneath and causing severe lameness for a time.

Treatment.--Simple frostbites are best treated by cold fomentations followed by applications of a 5 per cent solution of carbolized oil. When portions of the skin are destroyed, their early separation should be hastened by warm fomentations and poultices. Ulcers are to be treated by the application of stimulating dressings, such as carbolized oil, a 1 per cent solution of nitrate of silver or of chlorid of zinc, with pads of oakum and flannel bandages. In many of these cases recovery is exceedingly slow. The new tissue by which the destroyed skin is replaced always shrinks in healing, and, as a consequence, unsightly scars are unavoidable. When the coronary band is involved it is generally advisable to blister the coronet over the seat of injury as soon as the suppuration ceases, for the purpose of stimulating the growth of new horn. Where a crevasse is formed between the old and the new horn no serious trouble is liable to be met with until the cleft is nearly grown out, when the soft tissues may be exposed by a breaking off of the partly detached horn. But even if this accident happens final recovery is effected by poulticing the foot until a sufficient growth of horn protects the parts from injury.

QUITTOR.

Quittor is a term applied to various affections of the foot wherein the tissues which are involved undergo a process of degeneration that results in the formation of a slough followed by the elimination of the diseased structures by means of a more or less extensive suppuration.

For convenience of consideration quittors may be divided into four classes, as suggested by Girard: (1) Cutaneous quittor, which is known also as simple quittor, skin quittor, and carbuncle of the coronet; (2) tendinous quittor; (3) subhorny quittor; and (4) cartilaginous quittor.

CUTANEOUS QUITTOR.

Simple quittor consists in a local inflammation of the skin and subcutaneous connective tissue on some part of the coronet, followed by a slough and the formation of an ulcer which heals by suppuration.

It is an extremely painful disease, owing to the dense character of the tissues involved; for in all dense structures the swelling which accompanies inflammation always produces intense pressure. This pressure not only adds to the patient's suffering but may at the same time endanger the life of the affected parts by strangulating the blood vessels. It is held by some writers that simple quittor is most often met with in the hind feet, but in my experience more than two-thirds of the cases have developed in the fore feet. While any part of the coronet may become the seat of attack, the heels and quarters are undoubtedly most liable.

Causes.--Bruises and other wounds of the coronet are often the cause of cutaneous quittor, yet there can be no question that in the great majority of cases the disease develops without any known cause. For some reason not yet satisfactorily explained most cases happen in the fall of the year. One explanation of this fact has been attempted in the statement that the disease is due to the injurious action of cold and mud. This claim, however, seems to lose force when it is remembered that in many parts of this country the most mud, accompanied with freezing and thawing weather, is seen in the early springtime without a corresponding increase of quittor. Furthermore, the serious outbreaks of this disease in the mountainous regions of Colorado, Wyoming, and Montana are seen in the fall and winter seasons, when the weather is the driest. It may be claimed, and perhaps with justice, that during these seasons, when the water is low, animals are compelled to wade through more mud to drink from lakes and pools than is necessary at other seasons of the year, when these lakes and pools are full. Add to these conditions the further fact that much of this mud is impregnated with alkaline salts which, like the mineral substances always found in the mud of cities, are more or less irritating, and it seems fair to conclude that under certain circumstances mud may become an important factor in the production of quittor.[3]

While this disease attacks any and all classes of horses, it is the large, common breeds, with thick skins, heavy coats, and coarse legs that are most often affected. Horses well groomed and cared for in stables seem to be less liable to the disease than those running at large or than those which are kept and worked under adverse circumstances.

Symptoms.--Lameness, lasting from one to three or four days, nearly always precedes the development of the strictly local evidences of quittor. The next sign is the appearance of a small, tense, hot, and painful tumor in the skin of the coronary region. If the skin of the affected foot is white, the inflamed portion will present a dark-red or even a purplish appearance near the center. Within a few hours the ankle, or even the whole leg as high as the knee or hock, becomes much swollen. The lameness is now so great that the patient refuses to use the foot at all, but carries it if compelled to move. As a consequence, the opposite leg is required to do the work of both, and if the animal persists in standing a greater part of the time it, too, becomes swollen. In many of these cases the suffering is so intense during the first few days as to cause general fever, dullness, loss of appetite, and increased thirst. Generally the tumor shows signs of suppuration within 48 to 72 hours after its first appearance; the summit softens, a fluctuating fluid is felt beneath the skin, which soon ulcerates completely through, causing the discharge of a thick, yellow, bloody pus, containing shreds of dead tissue which have sloughed away. The sore is now converted into an open ulcer, generally deep, nearly or quite circular in outline, and with hardened base and edges. In exceptional cases large patches of skin, varying from 1 to 2-1/2 inches in diameter, slough away at once, leaving an ugly superficial ulcer. These sores, especially when deep, suppurate freely, and if there are no complications they tend to heal rapidly as soon as the degenerated tissue has softened and is entirely removed. When suppuration is fully established, the lameness and general symptoms subside. When but a single tumor and abscess form, the disease progresses rapidly, and recovery, under proper treatment, may be effected in from two to three weeks; but when two or more tumors are developed at once, or if the formation of one tumor is rapidly succeeded by another for an indefinite time, the sufferings of the patient are greatly increased, the case is more difficult to treat, and recovery is more slow and less certain.

This form of quittor is often complicated with the tendinous and subhorny quittors by an extension of the sloughing process.

Treatment.--The first step in the treatment of an outbreak of quittor should be the removal of all exciting causes. Crowding animals into small corrals and stables, where injuries to the coronet are likely to happen from trampling, especially among unbroken range horses, must be avoided as much as possible.

Watering places accessible without having to wade through mud should be provided. In towns, where the mud or dust is largely impregnated with mineral products, it is not possible to adopt complete preventive measures. Much can be done, however, by careful cleansing of the feet and legs as soon as the animal returns from work. Warm water should be used to remove the mud and dirt, after which the parts are to be thoroughly dried with soft cloths.

The means which are to be adopted for the cure of cutaneous quittor vary with the stage of the disease at the time the case is presented for treatment. If the case is seen early--that is, before any of the signs of suppuration have developed--the affected foot is to be placed under a constant stream of cold water, with the object of arresting a further extension of the inflammatory process. To accomplish this, put the patient in slings in a narrow stall having a slat or open floor. Bandage the foot and leg to the knee or hock, as the case may be, with flannel bandages loosely applied. Set a tub or barrel filled with cold water above the patient, and by the use of a small rubber hose of sufficient length make a siphon which will carry the water from the bottom of the tub to the leg at the top of the bandage. The stream of water should be quite small, and is to be continued until the inflammation has entirety subsided or until the presence of pus can be detected in the tumor. When suppuration has commenced, the process should be aided by the use of warm baths and poultices of lineseed meal or boiled turnips. If the tumor is of rapid growth, accompanied with intense pain, relief is obtained and sloughing largely limited by a free incision of the parts. The incision should be vertical and deep into the tumor, care being taken not to divide the coronary band entirely. If the tumor is large, more than one incision may be necessary.

The foot should now be placed in a warm bath for half an hour or longer and then poulticed. The hemorrhage produced by the cutting and encouraged by the warm bath is generally very copious and soon gives relief to the overtension of the parts.

In other cases it will be found that suppuration is well under way, so that the center of the tumor is soft when the patient is first presented for treatment. It is always good surgery to relieve the tumor of pus whenever its presence can be detected; hence, in these cases a free incision must be made into the softened parts, the pus evacuated, and the foot poulticed.

By surgical interference the tumor is now converted into an open sore or ulcer, which, after it has been well cleaned by warm baths and poultices applied for two or three days, needs to be protected by proper dressings. The best of all protective dressings is made of small balls, or pledgets, of oakum, carefully packed into the wound and held in place by a roller bandage 4 yards long, from 3 to 4 inches wide, made of common bedticking and skillfully applied.

The remedies which may be used to stimulate the healing process are many, and, as a rule, they are applied in the form of solutions or tinctures.

In my own practice I prefer a solution of bichlorid of mercury 1 part, water 500 parts, with a few drops of muriatic acid or a few grains of muriate of ammonia added to dissolve the mercury. The balls of oakum are wet with this solution before they are applied to the wound.

Among the other remedies which may be used, and perhaps with equally as good results, will be noted the sulphate of copper, iron, and zinc, 5 grains of either to the ounce of water; chlorid of zinc, 5 grains to the ounce; carbolic acid, 20 drops dissolved in an equal quantity of glycerin and added to 1 ounce of water; and nitrate of silver, 10 grains to the ounce of water.

If the wound is slow to heal, it will be found of advantage to change the remedies every few days.

If the wound is pale in color, the granulations transparent and glistening, the tincture of aloes, tincture of gentian, or the spirits of camphor may do best.

When the sore is red in color and healing rapidly, an ointment made of 1 part of carbolic acid to 40 parts of cosmoline or vaseline is all that is needed.

If the granulations continue to grow until a tumor is formed which projects beyond the surrounding skin, it should be cut off with a sharp, clean knife, and the foot poulticed for twenty-four hours, after which the wound is to be well cauterized daily with lunar caustic and the bandages applied with great firmness.

The question as to how often the dressings should be renewed must be determined by the condition of the wound, etc. If the sore is suppurating freely, it will be necessary to renew the dressing every 24 or 48 hours; if the discharge is small in quantity and the patient comfortable, the dressing may be left on for several days; in fact, the less often the wound is disturbed, the better, so long as the healing process is healthy. When the sore commences to "skin over," the edges should be lightly touched with lunar caustic at each dressing. The patient may now be given a little exercise daily, but the bandages must be kept on until the wound is entirely healed.

TENDINOUS QUITTOR.

This form of quittor differs from the cutaneous in that it not only affects the skin and subcutaneous tissues, but involves also the tendons of the leg, the ligaments of the joints, and, in many cases, the bones of the foot as well.

Fortunately, this form of quittor is less common than the preceding, yet any case beginning as simple cutaneous quittor may at any time during its course become complicated by the death of some part of the tendons, by gangrene of the ligaments, sloughing of the coronary band, caries of the bones, or inflammation and suppuration of the synovial sacs and joints, thereby converting a simple quittor into one which will, in all probability, either destroy the patient's life or maim him for all time.

Causes.--Tendinous quittor is caused by the same injuries and influences that produce the simple form. Zundel believes it to be a not infrequent accompaniment of distemper. In my own experience I have seen nothing to verify this belief, but I am convinced that young animals are more liable to have tendinous quittor than older ones, and that they are much more likely to make a good recovery.

Symptoms.--When a case of simple quittor is transformed into the tendinous variety the change is announced by a sudden increase in the severity of all the symptoms. On the other hand, if the attack primarily is one of tendinous quittor, the earliest symptom seen is a well-marked lameness. In those cases due to causes other than injuries this lameness is at first very slight, and the animal limps no more in trotting than in walking; later on, generally during the next 48 hours, the lameness increases to such extent that the patient often refuses to use the leg at all. An examination made during the first two days rarely discloses any cause for this lameness; it may not be possible even to say with certainty that the foot is the seat of the trouble. On the third or fourth day, sometimes as late as the fifth, a doughy-feeling tumor will be found forming on the heel or quarter. This tumor grows rapidly, feels hot to the touch, and is extremely painful. As the tumor develops, all the other symptoms increase in intensity; the pulse is rapid and hard; the breathing quick; the temperature elevated 3 deg. or 4 deg.; the appetite is gone; thirst increased; and the lameness so great that the foot is carried if locomotion is attempted. At this stage of the disease the patient generally seeks relief by lying upon the broad side, with outstretched legs; the coat is bedewed with a clammy sweat, and every respiration is accompanied with a moan. The leg soon swells to the fetlock; later this swelling gradually extends to the knee or hock, and in some cases reaches the body. As a rule, several days elapse before the disease develops a well-defined abscess, for, owing to the dense structure of the bones, ligaments, and tendons, the suppurative process is a slow one, and the pus is prevented from readily collecting in a mass.

I made a post-mortem examination on a typical case of this disease, in which the animal had died on the fourth day after being found on the range slightly lame. The suffering had been intense, yet the only external evidences of the disease consisted in the shedding of the hoof from the right fore foot and a limited swelling of the leg to the knee. The sloughing of the hoof took place two or three hours before death, and was accompanied with but little suppuration and no hemorrhage. The skin from the knee to the foot was thickened from watery infiltration (edema), and on the inside quarter three holes, each about one-half inch in diameter, were found. All had ragged edges, while but one had gone deep enough to perforate the coronary band. The loose connective tissue beneath the skin was distended, with a gelatinous infiltration over the whole course of the flexor tendons and to the fetlock joint over the tendon in front. The soft tissues covering the coffin bone were loosened in patches by collections of pus which had formed beneath the sensitive laminae. The coffin and pastern joints were inflamed, as were also the coffin, navicular, and coronet bones, while the outside toe of the coffin bone had become softened from suppuration until it readily crumbled between the fingers. The coronary band was largely destroyed and completely separated from the other tissues of the foot. The inner lateral cartilage was gangrenous, as was also a small spot on the extensor tendon near its point of attachment on the coffin bone. Several small collections of pus were found deep in the connective tissue of the coronary region; along the course of the sesamoid ligaments; in the sheath of the flexor tendons; under the tendon just below the fetlock joint in front; and in the coffin joint.

But all cases of tendinous quittor are by no means so complicated as this one was. In rare instances the swelling is slight, and after a few days the lameness and other symptoms subside, without any discharge of pus from an external opening. In most cases, however, from one to half a dozen or more soft points arise on the skin of the coronet, open, and discharge slowly a thick, yellow, fetid, and bloody matter. In other cases the suppurative process is largely confined to the sensitive laminae and plantar cushion, when the suffering is intense until the pus finds an avenue of escape by separating the hoof from the coronary band, at or near the heels, without causing a loss of the whole horny box. When the flexor tendon is involved deep in the foot, the discharge of pus usually takes place from an opening in the follow of the heel; if the sesamoid ligament or the sheath of the flexors are affected, the opening is nearer the fetlock joint, although in most of these cases the suppuration spreads along the course of the tendons until the navicular joint is involved, and extensive sloughing of the deeper parts follows.

Treatment.--The treatment of tendinous quittor is to be directed toward the saving of the foot. First of all an effort must be made to prevent suppuration; if the patient is seen at the beginning, cold irrigation, recommended in the treatment for cutaneous quittor, is to be resorted to. Later, when the tumor is forming on the coronet, the knife must be used, and a free and deep incision made into the swelling. Whenever openings appear, from which pus escapes, they should be carefully probed; in all instances these fistulous tracts lead down to dead tissue which nature is trying to remove by the process of sloughing. If a counter opening can be made, which will enable a more ready escape of the pus, it should be done at once; for instance, if the probe shows that the discharge originates from the bottom of the foot, the sole must be pared through over the seat of trouble. Whenever suppuration has commenced the process is to be stimulated by the use of warm baths and poultices. The pus which accumulates in the deeper parts, especially along the tendons, around the joints, and in the hoof, is to be removed by pressure and injections made with a small syringe, repeated two or three times a day. As soon as the discharge assumes a healthy character and diminishes in quantity, stimulating solutions are to be injected into the open wounds. When the tendons, ligaments, and other deeper parts are affected, a strong solution of carbolic acid--1 to 4--should be used at first; or strong solutions of tincture of iodin, sulphate of iron, sulphate of copper, bichlorid of mercury, etc., may be used in place of the carbolic; after this the remedies and dressings directed for use in simple quittor are to be used. In those cases in which the fistulous tracts refuse to heal it is often necessary to burn them out with a saturated solution of caustic soda, equal parts of muriatic acid and water, or, better still, with a long, thin iron, heated white hot.

But no matter what treatment is adopted, a large percentage of the cases of tendinous quittor fail to make good recoveries. If the entire hoof sloughs away, the growth of a new, but soft and imperfect hoof may be obtained by carefully protecting the exposed tissues with proper bandages. When the joints are opened by deep sloughing, recovery may eventually take place, but the joint remains immovable ever after. If caries of a small part of the coffin bone takes place, it may be removed by an operation; but if much of the bone is affected, or if the navicular and coronet bones are involved in the carious process, the only hope for a cure is in the amputation of the foot. This operation is advisable only when the animal is valuable for breeding purposes. In all other cases in which there is no hope for recovery the patient's suffering should be relieved by death. In tendinous quittor much thickening of the coronary region, and sometimes of the ankle and fetlock, remains after suppuration has ceased and the fistulous tracts have healed. To stimulate the reabsorption of this new and unnecessary tissue, the parts should be fired with the hot iron, or, in its absence, repeated blistering with the biniodid of mercury ointment may largely accomplish the same results.

SUBHORNY QUITTOR.

This is the most common form of the disease. It is generally seen in but one foot at a time, and more often in the fore than in the hind feet. It nearly always attacks the inside quarter, but may affect the outside, the band in front, or the heel, where it is of but little consequence. It consists in the inflammation of a small part of the coronary band and adjacent skin, followed by sloughing and suppuration, which in most cases extends to the neighboring sensitive laminae.

Causes.--Injuries to the coronet, such as bruises, overreaching, and calk wounds, are considered as the common causes of this disease. Still, cases occur in which there appears to be no existing cause, just as in the other forms of quittor, and it seems fair to conclude that subhorny quittor may also be produced by internal causes.

Symptoms.--At the outset the lameness is always severe, and the patient often refuses to use the affected foot. Swelling of the coronet close to the top of the hoof causes the quarter to protrude beyond the wall. This tumor is extremely sensitive, and the whole foot is hot and painful. After a few days a small spot in the skin, over the most elevated part of the tumor, softens and opens or the hoof separates from the coronary band at the quarter or well back toward the heel. From this opening, wherever it may be, a thin, watery, often dark, offensive discharge escapes, at times mixed with blood and always containing a considerable percentage of pus.

Probing will now disclose a fistulous tract leading to the bottom of the diseased tissues. If the opening is small, there is a tendency upon the part of the suppurative process to spread downward; the pus gradually separates the hoof from the sensitive laminae until the sole is reached, and even a portion of this may be undermined.

As a rule, the slough in this form of quittor is not deep, and if the case receives early and proper treatment complications are generally avoided; but if the case is neglected, and, occasionally, even in spite of the best treatment, the disease spreads until the tendon in front, the lateral cartilage, or the coffin bone and joint as well are involved.

In all cases of subhorny quittor much relief is experienced when the slough comes away, and rapid recovery is made. If, however, after the lapse of a few days, the lameness remains and the wound continues to discharge a thin, unhealthy matter, the probabilities are that the disease is spreading, and pus collecting in the deeper parts of the foot. In Zundel's opinion, if the use of the probe now detects a pus cavity below the opening, a cartilaginous quittor is in the course of development.

Treatment.--Hot baths and poultices are to be used until the presence of pus can be determined, when the tumor is to be opened with a knife or sharp-pointed iron heated white hot. The hot baths and poultices are now continued for a few days or until the entire slough has come away and the discharge is diminished, when dressings recommended in the treatment for cutaneous quittor are to be used until recovery is completed. In cases in which the discharge comes from a cleft between the upper border of the hoof and the coronary band, always pare away the loosened horn, so that the soft tissues beneath are fully exposed, care being taken not to injure the healthy parts. This operation permits of a thorough inspection of the diseased parts, the easy removal of all gangrenous tissue, and a better application of the necessary remedies and dressings. The only objection to the operation is that the patient is prevented from being early returned to work.

When the probe shows that pus has collected under the coffin bone the sole must be pared through, and, if caries of the bone is present, the dead parts cut away. After either of these operations the wound is to be dressed with the oakum balls, saturated in the bichlorid of mercury solution, as previously directed, and the bandages tightly applied. Generally the discharge for the first two or three days is so great that the dressings need to be changed every 24 hours; but when the discharge diminishes, the dressing may be left on from one to two weeks. Before the patient is returned to work, a bar shoe should be applied, since the removed quarter or heel can only be made perfect again by a new growth from the coronary band.

Tendinous or cartilaginous complications are to be treated as directed under those headings.

CARTILAGINOUS QUITTOR.

This form of quittor may commence as a primary inflammation of the lateral cartilage, but in the great majority of cases it appears as a sequel to cutaneous or subhorny quittor. It may affect either the fore or hind feet, but is most commonly seen in the former. As a rule, it attacks but one foot at a time, and but one of the cartilages, generally the inner one. It is always a serious affection for the reason that, in many cases, it can only be cured by a surgical operation, requiring a thorough knowledge of the anatomy of the parts involved, and much surgical skill.

Causes.--Direct injuries to the coronet, such as trampling, pricks, burns, and the blow of some heavy falling object which may puncture, bruise, or crush the cartilage, are the common direct causes of cartilaginous quittor. Besides being a sequel to the other forms of quittor, it sometimes develops as a complication in suppurative corn, canker, grease, laminitis, and punctured wounds of the foot. Animals used for heavy draft, and those with flat feet and low heels, are more liable to the disease than others, for the reason that they are more exposed to injury. Rough roads also predispose to the disease by increasing liability to injury.

Symptoms.--When the disease commences as a primary inflammation of the cartilage, lameness develops with the formation of a swelling on the side of the coronet over the quarter. The severity of this lameness depends largely upon the part of the cartilage which is diseased, for if the disease is situated in that part of the cartilage nearest the heel, where the surrounding tissues are soft and spongy, the lameness may be very slight, especially if the patient is required to go no faster than a walk; but when the middle and anterior parts of the cartilage are diseased, the pain and consequent lameness are much greater, for the tissues are less elastic and the coffin joint is more liable to become affected.

Except in the cases to be noted hereafter, one or more fistulous openings finally appear in the tumor on the coronet. These openings are surrounded by a small mass of granulations which are elevated above the adjacent skin and bleed readily if handled. A probe shows these fistulous tracts to be more or less sinuous, but always leading to one point--the gangrenous cartilage. When cartilaginous quittor happens as a complication of suppurative corn, or from punctured wounds of the foot, the fistulous tract may open alone at the point of injury on the sole.

The discharge in this form of quittor is generally thin, watery, and contains pus enough to give it a pale-yellow color; it is offensive to the sense of smell, due to the detachment of small flakes of cartilage which have become gangrenous and are seen in the discharge as small, greenish-colored particles. In old cases it is not unusual to find some of the fistulous openings heal at the surface; this is followed by the gradual collection of pus in the deeper parts, forming an abscess, which in a short time opens at a new point. The wall of the hoof, over the affected quarter and heel, in very old cases becomes rough and wrinkled like the horn of a ram, and generally it is thicker than the corresponding quarter, owing to the stimulating effect which the disease has upon the coronary band.

Complications may arise by an extension of the disease to the lateral ligament of the coffin joint, to the joint itself, to the plantar cushion, and by caries of the coffin bone.

Treatment.--Before recovery can take place all the dead cartilage must be removed. In rare instances this is effected by nature without assistance. Usually, however, the disease does not tend to recovery, and active curative measures must be adopted. The best and simplest treatment, in a majority of cases, is the injection of strong caustic solutions, which destroy the diseased cartilage and cause its discharge, along with the other products of suppuration. In favorable cases these injections will secure a healing of the wound in from two to three weeks. While the saturated solution of sulphate of copper, or a solution of 10 parts of bichlorid of mercury to 100 parts of water, has given the best results in my hands, equally as favorable success has been secured by others from the use of caustic soda, nitrate of silver, sulphate of zinc, tincture of iodin, etc. No matter which one of these remedies may be selected, however, it must be used at least twice a day for a time. The solution is injected into the various openings with force enough to drive it to the bottom of the wound, after which the foot is to be dressed with a pad of oakum, held in place by a roller bandage tightly applied. While it is not always necessary, it is often of advantage to relieve the pressure on the parts by rasping away the hoof over the seat of the cartilage; the coronary band and laminae should not be injured in the operation.

If the caustic injections prove successful, the discharge will become healthy and gradually diminish, so that by the end of the second week the fistulous tracts are closing up and the injections are made with much difficulty.

If, on the other hand, there is but little or no improvement after this treatment has been used for three weeks, it may reasonably be concluded that the operation for the removal of the lateral cartilage must be resorted to for the cure of the trouble. As this operation can be safely undertaken only by an expert surgeon, it will not be described in this connection.

THRUSH.

Thrush is characterized by an excessive secretion of unhealthy matter from the cleft of the frog. While all classes of horses are liable to this affection, it is more often seen in the common draft horse than in any other breed, owing to the conditions of servitude and not to the fault of the breed. Country horses are much less subject to the disease, except in wet, marshy districts, than are the horses used in cities and towns.

Causes.--The most common cause of thrush is the filthy condition of the stable in which the animal is kept. Mares are more liable to contract the disease in the hind feet when filth is the cause, while the gelding and stallion are more liable to develop it in the fore feet. Hard work on rough and stony roads may also induce the disease, as may a change from dryness to excessive moisture. The latter cause is often seen to operate in old track horses, whose feet are constantly soaked in the bathtub for the purpose of relieving soreness. Muddy streets and roads, especially where mineral substances are plentiful, excite this abnormal condition of the frog. Contracted heels, scratches, and navicular disease predispose to thrush, while by some a constitutional tendency is believed to exist among certain animals which otherwise present a perfect frog.

Symptoms.--At first there is simply an increased moisture in the cleft of the frog, accompanied with an offensive smell. After a time a considerable discharge takes place--thin, watery, and highly offensive, changing gradually to a thicker puriform matter, which rapidly destroys the horn of the frog. Only in old and severe cases is the patient lame and the foot feverish--cases in which the whole frog is involved in the diseased process.

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