Diseases of poultry; their etiology, diagnosis, treatment, and prevention

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Preface

It is probably safe to say that considerably more than fifty per cent of the correspondence of those engaged in poultry work in the agricultural colleges and experiment stations in this country relates to poultry diseases. The poultryman or farmer sees that some, or perhaps all, of his birds are ill, and he straightway writes to the nearest college or station to know what the disease is, and what to do for it. ‘The Maine Station has for many years been the recipient of a great number of such inquiries. It is an unfortunate, but in the nature of the case an unavoidable fact, that in many instances it is quite impossible to make any really satisfactory reply to these inquiries. In the vast majority of cases the person who writes the letter is quite untrained in pathology and either describes no symptoms at all or only those very general ones which are common to nearly all the ills of poultry. ‘To one who has not handled this class of correspondence it would seem almost incredible that there should be so many letters of the following type: “I have lost about a third of my chickens in the last few days. ‘They seem a little dumpish for a while and then die. What is the trouble and what shall I do for it?” To diagnose and prescribe on such a basis of information is impossible. Yet the hard fact remains that the correspondent’s chickens were ill and did die, and he needs help to get out of the trouble.

Only recently has any attempt been made by our agricultural colleges to prepare its graduates in poultry husbandry and general agriculture to meet intelligently these

V vi Preface problems of poultry disease. Indeed even the veterinary schools have given but scant attention to avian pathology. Yet there exists, scattered in the literature, a large amount of definite information regarding poultry diseases. It was the purpose of the first edition of the circular on which the present book is based to give a clear and reasonably complete compilation and digest of the information then existing in the literature regarding the commoner diseases of poultry, their diagnosis, etiology, treatment, and prognosis.

The material was put together in the form which seemed most likely to meet the needs of the practical poultryman. It was soon found that in addition to this use, the book was coming to be rather widely employed as a text-book for courses in the diseases of poultry in agricultural colleges and high schools. In preparing the present edition the authors have kept more definitely in mind this second way in which the book may prove useful, and have added on that account some material not likely to be of immediate interest to the poultryman.

While none of the authors is engaged in researches in pathology, it is a fact that they have all had extensive experience in the appearance at autopsy of chickens dead from some one or more of a very wide variety of causes. There are but very few diseases mentioned in the book with which the authors have not had first-hand experience. It is hoped that the knowledge gained in this way will prove to have been of some critical value in the compuilation of this book.

PREFACE

LIST OF

CHAPTER

I. XV

XVI.

XVII.

XVITTI.

XIX.

XX.

XXI.

Table Of Contents

ILLUSTRATIONS : : : : : : : 5

GENERAL CONSIDERATIONS REGARDING THE TREAT- MENT OF POULTRY DISEASES ; : : ‘ PouttTrRY HYGIENE 5 i ; 3 ‘ : THE DIAGNOSIS OF THE DISEASES OF POULTRY Pouttry Materia MeEpIcA : s ; ; 2 DISEASES OF THE ALIMENTARY TRACT . : ‘ POISONS . j . ; : : , : ‘ ; DISEASES OF THE LIVER . ; . : ; ; Fow.t CHouera, Fowi TypHoip AND Fowi PLAGUE TUBERCULOSIS f : : : : ' ; : INTERNAL PARASITES . : ‘ 5 5 ; 5 DISEASES OF THE RESPIRATORY SYSTEM . : : DISEASES OF THE CIRCULATORY SYSTEM . : : DISEASES OF THE NERVOUS SYSTEM . : : : DISEASES RHEUMATISM LIMBERNECK . ; ; ; ; ; ; :

OF THE KIDNEYS, EXTERNAL PARASITES . ; ‘ ; : ; DISEASES OF THE SKIN ; : : 4 DISEASES OF THE REPRODUCTIVE ORGANS : : WHITE DIARRHEA ‘ f ; : : ; ‘ OTHER DISEASES OF CHICKENS . ; ; é : TUMORS ; ; ; : ; 3 é 5 ; PouLTRY SURGERY : 4 A 5 5 ; :

CHAPTER I GENERAL CONSIDERATIONS REGARDING THE TREATMENT OF PowuLtTRY DISEASES

THERE is general agreement on the part of authorities on poultry pathology and practical poultrymen of long experience that, in general, “doctoring”’ poultry is not advisable. The reasons for this attitude are primarily the following :

1. The unit of production with poultry (7.e., the individual bird) is of relatively small value, and if a man’s time is worth anything, it is too valuable to spend treating sick chickens individually unless they are show specimens of great individual value.

2. The “cured” chicken is a menace to the owner, because its identity is likely to be overlooked or forgotten, with the result that it goes into the breeding pen and perpetuates through its offspring the constitutional weakness which was one fundamental factor in bringing about the result that it, rather than some of its fellows, was ill.

This point of view has been well stated by Wright ! in the following words:

“In a large proportion of cases of disease, the birds ought to die or be killed. Even where there is no constitutional taint, the fact that they have succumbed to circumstances which

1 Wright, L., ‘The New Book of Poultry.’’ London (Cassell & Company), 1905.

B 1 have not affected others, marks them out as the weakest, which unaided Nature would assuredly weed out, and which if we preserve and breed from, perpetuate some amount of that weakness in the progeny. Rheumatism, for instance, ean be cured; of that there is no doubt. But the vast majority who have had such success, agree that the effects are either never recovered from, as regards strength and vigor, or else that the original weakness continues; and the same may be said of some severe contagious diseases, such as diphtheritic roup, which may affect the strongest. On the other hand, many diseases also apparently contagious, and so attacking healthy birds under certain predisposing conditions of exposure or other coincident strain upon the system, do not appear to leave serious results behind them, and are tolerably definite in symptoms and character. It is these which may be most successfully treated, and in which treatment is most worth while where fowls of value are concerned. But it is significant that nearly all breeders who rear really large numbers of poultry, gradually come to the conclusion that, except in special eases, with valuable birds, the most economical treatment of serious disease occurring in a yard is— execution. Concerning this matter each must judge for himself.”

In the ease of the utility poultryman, keeping poultry solely for the eggs and meat they produce, practically the only diseased conditions which it will pay him to treat at all are those in which the treatment can be applied to the flock as a whole, without the necessity of handling individual birds. Thus, for example, in cases where the flock “goes off its feed,” or has simple indigestion or a mild cold, the birds can be treated successfully as a flock. On the other hand, in the case of the fancier, who has individual birds of considerable value, there will be a much wider range of diseases which he will feel that it is profitable for him to treat. There

General Considerations 3 are, of course, certain diseased conditions which demand. individual treatment, but in which the treatment is so simple and the outcome is almost certain to be so good, as to justify its employment even in the case of birds of ordinary value. An example of such a condition is found in a crop-bound bird.

Prevention Rather Than Cure the Ideal

The aim of every poultry keeper, whether his interest is in the fancy or the utility end of the business, should be to breed and manage his birds so as to prevent entirely, or reduce to a minimum, the occurrence of disease. In other words, the attitude should be that the end to be sought is to prevent the occurrence of disease, rather than to rely

on a rather dubious ability to cure it after it is there. Such a standpoint is sound from every point of view; it is in line with the whole development of modern medicine. The poultry doctor should regard his function as the same as that of the Chinese physician, who is primarily employed to keep the patient from becoming ill, only secondarily to cure him.

Now there are fundamentally two factors involved in the continued maintenance of good health in poultry (or, for the matter of that, in any other animal). These are:

1. A sound and wgorous constitution, which if present, 1s something innate and “bred in the bone,” and which, if absent, must be bred into the stock.

2. A system of poultry management (including feeding, housing, etc.) which rs thoroughly and absolutely hygienic.

We shall consider each of these factors separately in some detail.

Breeding for Health, Vigor and Sound Constitution —

To have a high degree of constitutional vigor in the _ foundation stock is one of the most certain assurances that the poultryman will not be troubled with disease. This is of primary importance. In order to breed constitutional vigor into the flock, the poultryman must train himself to recognize at a glance the condition of his birds. Are they in good condition or not? Regarding the aspect of fowls in health and disease Salmon! has the following to say:

“We say that a bird is in good health when it appears lively, has a clear eye, a bright red comb, is quick and active in its movements, has a good appetite and when the various organs perform their functions in the manner in which they are observed to act in all birds that are vigorous and thriving. On the other hand, we say a bird is diseased when some function or functions of its body are not performed as they are in the great majority of individuals, or when some organ presents an unusual form or appearance. Disease has, therefore, been defined as a life the manifestations of which deviate more or less from the normal. Practically, we say a bird is diseased when we observe that one or more of its functions are not carried on in a normal manner, or when we find unusual growths, injuries, or parasites affecting any of its organs.”

Having acquired the ability to see the individual birds as individuals, the next step is to learn to distinguish a good bird from a poor one. Here it is ever to be kept in mind that the primary and most essential characteristic of a good bird must always be a sound constitution and plenty of vitality and vigor. Without these qualities it is impossible to have first class stock. Constitutional vigor and vitality may be put as a fundamental requisite in the successful practical breeding of poultry. In all kinds of breeding operations whether for utility purposes, or for the fancier’s show pen, or for the purpose of experimentation in the field

1Salmon, D. E., ‘‘The Diseases of Poultry.’”’ Washington (no date).

13) | of heredity, the first selection of birds for the breeding pen should be made on the basis of their general constitutional vigor. No bird which shows signs of weakness in this fundamental regard should ever be used as a breeder under any circumstances. If such a bird is used the breeder will eventually have to pay the penalty.

The external, visible evidences of a sound constitution and a possession of abundant vitality and vigor are numerous. In the first place the bird of sound constitution will be in perfect health. Perhaps its most striking characteristic will be an independence of disposition and demeanor. By this is not necessarily meant aggressiveness. The bird, whether male or female, which is forever picking quarrels with its fellows is by no means always the bird of greatest vigor. Strange as it may seem a bird may indeed be very far from a mollycoddle and yet have a peaceable disposition. It may be taken as an unfailing characteristic of birds of high constitutional vigor, however, that they are able to take care of themselves and may not be imposed upon, or bullied by their fellows, with impunity. While they may not pick a quarrel, they are abundantly able to make a forceful presentation of the merits of their end of any debate which another bird may choose to enter upon with them. In other words they have, as has been said, an independence of disposition; an ability, reaching to the limits of gallinaceous capacity, to meet all situations which may arise in the day’ s work of a fowl, whether food getting, fighting, rearing young, or what not.

The bird of high constitutional vigor will have a thrifty appearance, with a bright eye, and clean, well-kept plumage. The head will be broad and relatively short, giving in its appearance plain indication of strength. It will show nothing of the long-drawn-out, sickly, crow-like appearance of the head which is all too common amongst the inhabitants

General Considerations a of the average poultry yard. The beak will be relatively short and strong, thus correlating with the general conformation of the head. Comb and wattles will be bright in color and present a full-blooded, healthy, vigorous appearance.

The body of the bird of high constitutional vigor will be broad and deep and well meated, with a frame well knit together, strong in the bone but not coarse. In fowls of strong

Fic. 2. — Six Silver-laced Wyandottes, which have great constitutional vigor and vitality. These birds averaged to lay 204 eggs each in a year. Only birds in perfect health and high constitutional vigor can make such records. (After D. S. Thompson.)

constitution and great vigor all the secondary sexual differences will usually be well marked. In other words the males will be masculine to a degree in appearance and behavior, and the females correspondingly feminine. It must be noted, however, that this last is a general rule to which there are occasional exceptions.

CHAPTER II Pouttry HYGIENE

SECOND in importance only to high constitutional vigor and health is attention to the basic rules of hygiene and sani- -tation in the management of poultry. In view of the prevalent misunderstanding or lack of understanding of these principles it seems wise to devote one chapter to an outline of the more important points which need to be looked after in hygienic poultry keeping. Attention to the rules and principles here set forth will go a great way towards preventing the occurrence of disease. ‘This does not mean that if these rules are not followed disease and destruction will forthwith result. Every one knows of plenty of instances of more or less successful poultry keeping under the most insanitary and unhygienic of conditions. So, similarly, human beings are able, when forced to do so, to live under unhygienic conditions. But every civilized country in the world believes that the most economical insurance against the steady loss of national wealth which the prevalence of disease involves is the enforcement of sanitary regulations throughout its domain. Again, many men who do not carry fire insurance on their buildings go through life without having any of them burn down. But this is no argument against the fact that it is a sound economic policy to carry fire insurance. In poultry keeping many may be successful for a time in managing their birds in defiance of the laws of sanitation and hygiene; a very few may be successful in this practice for a long time, but in the long run the vast majority will find that thorough, careful and _ intelligent attention to these laws will be one of the best guaranties of permanent success that they can find.

Poultry hygiene and sanitation will be considered here under seven main heads, as follows: I. Housing. II. Feeding. III. The Land. IV. Exercise. V. External Parasites. VI. Disposal of the Dead. VII. Isolation of Sickness. What is said under all of these heads is intended to apply (unless a specific statement to the contrary 1s made) both to adult birds and to chicks. No discussion of the hygiene of incubation, or of the relative merits of artificially and naturally hatched chickens will be undertaken here, because these are special subjects falling outside the field of general poultry hygiene.

I. Poultry House Hygiene and Sanitation

A. General Principles of Poultry Housing. —In the management of adult fowls there are in the main two things to be considered, housing and feeding. A _ vast multitude of methods of doing these two things to poultry have been tried during the history of the industry.

There have been published plans for poultry houses of all conceivable shapes and sizes. Long houses, short houses, tall houses, low houses; square, hexagonal, octagonal and round houses; heated houses and cold houses; all these and many more have had their advocates, and detailed plans for their construction can be found. It would appear that there must be realized here the primary condition of the experimental method, namely the “trying of all things.”’ It only remains to discover that which is “good” in order that we may “hold fast”’ to it.

This discovery had indeed been made in regard to a few of the basic things in the housing of poultry. It would be strange if something had not come out of all the indignities to which innocent and inoffensive generations of fowls have been submitted in the way of dwelling accommodations. It is now clearly recognized, and generally admitted by all competent poultrymen, that certain things are absolutely essential in any poultry house which is to give good results. These are (1) fresh air, (2) freedom from dampness, (3) freedom from draughts, (4) sunlight and (5) cleanliness.

If these five things are realized in a poultry house the birds will thrive and be productive in it, provided they are well and regularly fed and watered. It makes no difference particularly to the well-being of the birds how these necessary specifications of their dwelling are attained. To the poultryman, however, it is important that they be attained at the smallest expense, having regard to (a) initial cost, (b) repairs and up-keep and (c) labor necessary to operate the house to get the specified results. The housing problem is to the poultryman, then, both a biological and an economic one. The biological solution is definite. The requisites named above must be met, and there is one additional factor to be taken into account ; namely, size of house. Experiments made at various times and places indicate clearly that in northern climates, where birds must be shut up in the house during a part of the year in order to give best results, there should be allowed in the house at least three square feet of floor space per bird, and preferably a little more. our square feet floor space per bird is a liberal allowance. :

A factor which it was formerly thought necessary to control in the housing of poultry was the temperature. It was long held that if fowls were to lay well in the winter it was necessary that they should be in a heated house. Later experience has shown conclusively that this was an utterly

“OL i Diseases of Poultry fallacious idea. As a matter of fact, even in the coldest climates, fowls will lay better during the winter months in a properly constructed house wide open to the outside air in the day time, so that they are living practically out of doors, than in any heated house which has yet been devised. If a laying house is dry the temperature factor may be neglected. If a house has a tendency to dampness, it will give poor results regardless of temperature.

From the economic standpoint there are two systems of housing poultry to be considered. One of these is the system of long, continuous houses for the laying birds. The other is the so-called colony house system, in which the birds are housed in small separate houses which may either be set a considerable distance apart over a relatively wide area, or may be placed relatively near one another. Each system has its strenuous advocates. Experience covering a fairly long period of years now has demonstrated that both systems have good points. As to which shall be adopted in a particular instance depends upon a variety of considerations, each in some degree peculiar to the particular case in hand.

In the extreme northern part of the country where the climate is very cold in the winter and there is an abundance of snow there can be no question that the long house is much to be preferred to a colony system. ‘There are two reasons for this. In the first place experience indicates that the birds are somewhat more productive and keep in better condition in a properly constructed and managed long house than in colony houses. Furthermore the labor expense involved in caring for a given number of fowls 1s much less, under such climatic conditions, than with the colony house system, where the birds are scattered over a wider area and more paths must be broken out in the snow.

The great advantage of the colony house system 1s its

Poultry Hygvene

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OT flexibility. Furthermore it gets around the troubles involved in the contamination of the ground by the longcontinued keeping of poultry on the same small area. In general, local conditions and circumstances must decide in each individual case which system of housing shall be adopted. )

B. Cleanliness. —'The thing of paramount importance in the hygienic housing of poultry is cleanliness. By this is meant not merely plain, ordinary cleaning up, in the housewife sense, but also bacteriological cleaning up; that is, disinfection. All buildings or structures of whatever kind in which poultry are housed during any part of their lives should be subjected to a most thorough and searching cleaning and disinfection at least once every year. ‘This cleaning up should naturally come for each different structure (2.e., laying, colony or brooder house, individual brooder, incubator, ete.) at a time which just precedes the putting of new stock into this structure.

How to clean a poultry house. — Not every poultryman of experience even, knows how really to clean a poultry house. The first thing to do is to remove all the litter and loose dirt which can be shoveled out. Then give the house — floor, walls and ceiling —a thorough sweeping and shovel out the accumulated débris. Then play a garden hose, with the maximum water pressure which can be obtained, upon floor, roosting boards, walls and ceiling, until all the dirt which washes down easily is disposed of. Then take a heavy hoe or roost board scraper and proceed to scrape the floor and roosting boards, clean of the trampled and caked manure and dirt. ‘Then shovel out what has been accumulated and get the hose into action once more and wash the whole place down again thoroughly and follow this with another scraping. With a stiff bristled broom thoroughly scrub walls, floors, nest boxes, roost boards, ete. Then

Poultry Hygvene 15 after another rinsing down and cleaning out of accumulated dirt, let the house dry out for a day or two. ‘Then make a searching inspection to see if any dirt can be discovered. If so, apply the appropriate treatment as outlined above. If, however, everything appears to be clean, the time has come to make it really clean by disinfection. To do this it is necessary to spray or thoroughly wash with a scrub brush wet in the solution used all parts of the house with a good disinfectant at least twice, allowing time between for it to dry. For this purpose 3 per cent cresol solution is recommended. ‘The chief thing is to use an effective disinfectant and plenty of it, and apply it at least twice. A discussion of disinfectants immediately follows this section. To complete the cleaning of the house, after the second spraying of disinfectant is dry apply a liquid lice killer (made by putting 1 part crude carbolic acid or cresol with 3 parts kerosene) liberally to nests and roosts and nearby walls. After all this is done the house will be clean. In houses cleaned annually in this way the first step is taken towards hygienic poultry keeping.

The same principles which have been here brought out should be applied in cleaning brooders, brooder houses, and other things on the plant with which the birds come in contact.

What has been said has reference primarily to the annual or semiannual cleaning. It should not be understood by this that no cleaning is to be done at any othertime. On the contrary the rule should be to keep the poultry house clean at all times, never allowing filth of any kind to accumulate and using plenty of disinfectant.

Disinfection. —In the matter of disinfection there are several options open to the poultryman. He may make his own disinfectant, or he may purchase proprietary compounds like Zenoleum, Carbolineum or a host of other “eums”’

which confront him at every turn in his reading of poultry periodicals, or he may buy a plain disinfectant like formaldehyde, or carbolic acid.

There is no more effective general disinfectant than formaldehyde, and it also has the advantage of being cheap. We have used it regularly for some years past with excellent results. A 5 per cent solution of commercial formalin in water is applied to walls, floors and roost boards by means of a pressure spray pump. Various hand pumps of this type are on the market. It will pay the poultryman to get one of the well made higher priced sorts. If a spray pump is not available the formaldehyde solution may be put on with a brush. In any case a liberal amount should be used. When applying it all doors and windows should be open to diminish as much as possible the irritating effect of the vapor on the worker. His hands should also be protected by the use of well oiled leather gloves. '

Some writers have advocated the formaldehyde gas method for disinfecting poultry houses, using the permanganate method of generating. ‘This, however, is indicated only for rooms which can easily be closed up air tight. It costs too much in time and trouble to make any form of “fresh air’ poultry house even moderately air tight. The formaldehyde gas method is well adapted to disinfecting and fumigating feed rooms, incubator cellars, brooder houses and all houses which can be readily made air tight. For the benefit of those who wish to use the method for such purposes the following directions are given. This will give a very strong fumigation and disinfection but such is indicated about poultry establishments.

Formaldehyde gas disinfection. — First make the room as tight as possible by stopping cracks, key-holes, etc., with pieces of cloth or similar substance. Open bins and doors of closets, etc., to allow free access of the gas. Use a metal

Poultry Hygiene IL or earthen dish for a generator, of sufficient size so that the liquid will not spatter or boil over on the floor, since the permanganate will stain. The temperature of the room should not be below 50° F. and more effective disinfection will be obtained if the temperature is 80° F. or above at the beginning. Sprinkle boiling water on the floor or place a kettle of boiling water in the room to create a moist atmosphere. Spread the permanganate evenly over the bottom of the dish and quickly pour in the formaldehyde (40 per cent strength as purchased). Leave and tightly close the room at once and allow to remain closed for 4-6 hours or longer, then air thoroughly. Use 23 ounces of permanganate and 3 pints of formaldehyde to each 1000 cubic feet of space.

Cresol disinfectant.— For a disinfectant of the coal-tar or earbolic acid type, we have found a cheap and satisfactory sort to be compound cresol solution. This may be used alone or as a second spray following formalin for spraying and disinfecting the houses after they are cleaned, disinfecting brooders, brooder houses, incubators, nests and everything else about the plant which can be disinfected with a liquid substance. It is particularly effective against mites and other insect pests. It has been very satisfactory in disinfecting incubators between hatches. Any person can easily make this disinfectant. The following directions for its manufacture are quoted from Bulletin 179 of the Maine Agricultural Experiment Station.

The active base of cresol soap disinfecting solution is commercial cresol. This is a thick, sirupy fluid, varying in color in different lots from a nearly colorless fluid to a dark brown. It does not mix readily with water, and, therefore, in order to make satisfactory a dilute solution, it is necessary first to incorporate the cresol with some substance like soap which will mix with water and will carry the cresol over into the mixture. The commercial cresol, as it is obtained,

C is a corrosive substance, being in this respect not unlike carbolic acid. It should, of course, be handled with great care and the pure cresol should not be allowed to come in contact with the skin. If it does so accidentally the spot should be immediately washed off with plenty of clean water. The price of commercial cresol varies with the drug market. It can be obtained through any druggist. In purchasing this article one should order simply “commercial cresol.”’