Animal castration

Preface

This work is not intended for those unacquainted with anatomy, restraint of animals, principles of surgery and asepsis. It is assumed that the student is familiar with anatomy, and no attempt at such instruction has been made. However, anatomy is treated in sufficient detail for accurate description of the technic pertaining to the various operations considered. The reader's familiarity with the restraint of animals being presupposed, tedious recital of modes of restraint has been omitted; but the kind of restraint that will best serve any given operation has been indicated. Since a good working knowledge of the principles, of surgery and asepsis is necessary to comprehend the text, frequent reminders that instruments should be boiled and the operator's hands washed, have been purposely avoided. The selection of instruments is a matter of individual choice or custom, and, therefore, naming the instruments required for each operation described, has been intentionally omitted.

This volume is a resume of observations made during ten years' experience in the castration of animals. In considering the technic of operations, where more than one method is in vogue, tbe one that has proved the most practicable has been described.

The sections on equine umbilical hernia and cesarean operation in the sow have been included because these cases command much of the veterinarian's attention during the season of castration.

J. V. L.

October, 1915.

Appendix

Equine Umbilical Hernia 125

Index 142

ILLUSTRATIONS

FIGURE PAGE

1. A Castrating Knife with Convex Cutting Edge 15

2. A Castrating Knife Having a Hooked Blade 16

3. Emaseulator Hi

4. Ecraseur 17

5. Castration of the Colt in a Standing Position 19

(3. Eestraint for Castrating Colts 20

7. The ' ' Covered Operation " 27

8. A Modification of the ' ' Covered Operation " 31

9. Eestraint for Cryptorchid Castration 40

10. Genital Organs of the Bull 60

11. Castrating the Young Calf 61

12. Eestraint of Calf in Standing Position for Castration. . 02

13. Showing Position of Operator, Also Lines of Incision. . 63

14. Eueff 's Method of Casting 65

15. Showing Manner of Eestraint of Male Cat for Castration 84

16. A Form of Hippo-Lasso 91

17. Eestraint for Spaying 106

18. Median Line Incision for Spaying 108

19. The Ovary Within the Grasp of the Spaying Forceps. . Ill

20. Completing the Process of Limited Torsion for Amputation of the Ovary 112

21. Suture for Coaptation of the Peritoneum and Abdominal Muscles 113

22. Method of Tying Continuous Suture 114

23. Flank Incision for Spaying the Cat 121

Introduction

History

Castration of animals was practiced by the ancients as there is occasional mention of it in literature, but it is doubtful if this operation was performed on animals before it was practiced on the human. There is frequent allusion to castration or to one castrated in many literary works and data on this operation as practiced upon the human subject are readily obtained.

We quote from A Reference Handbook of the Medical Sciences, Vol. II, page 710: "Castration is a very ancient practice. It was a consequence of the system of polygamy. The word Eunuch means literally having charge of the bed chamber. The Hebrew word means mutilated, and the first royal chamberlains were probably castrated men. Later the term eunuch was applied to men in all sorts of offices and it lost its original meaning. ' '

"Herodotus relates that the castration of slaves was an industry among the Greeks. These slaves brought a high price in the markets of Ephesus. Early records of castration in China date back to 1100 B. C. Next to beheading it was at one time the most severe form of punishment."

Object

Reasons for the castrating of animals may be divided into two general classes. First, for economic purposes; making it possible to keep and work animals of both sexes together without difficulty, which would be impossible if the males were left entire; to regulate the reproductive numbers and thereby seek to elevate the standard of any given species ; and to obviate dangers of accidents and injuries occasioned by the instinctive combat between males. The second reason for animal castration is to work for the otherwise impossible correction of certain pathological conditions, such as infectious orchitis, and in some cases of strangulated hernia of the breeding male.

Castration has a marked effect upon the conformation of animals and viewed from the economical standpoint, this result is beneficial. Conformation is materially altered, and where the animal is castrated at an early age, the type is not so strongly developed as in the case of the unaltered subject. Geldings do not possess the physical maturity of stallions, being less powerful in appearance and lacking the large, masculine facial features of the stallion. The neck is more slender, the crest somewhat undeveloped, and the muscularity of the breast and forearms is not so pronounced, — in short, the entire body partakes of a finer and more feminine type. A similar but less observable condition occurs with respect to the unsexed female. This is true, in varying degrees, of all animals.

The character of the flesh of a castrated animal is also materially different from that of the uncas+rated, the flesh of the steer having a better flavor and being more tender and edible than, that of a bull. This is particularly noticeable in the flesh of swine, — the meat of the entire male hog or one castrated after attaining maturity, having a characteristic odor and being not really palatable.

The flow of milk is said to be appreciably prolonged in cows that have been spayed, but it is doubtful if

INTRODUCTION 11

the quality of the milk is improved in the least. In those instances where it is undesirable or inconvenient to breed milk cows, the estral period interferes materially with lactation at each regular recurrence. In such cases spaying is advisable.

The best age for castrating the various species is a much-debated question, as many circumstances govern, in a measure, the decision in different cases. It is generally conceded that a colt is best castrated between the ages of nine and twenty-four months, though some stock owners are firmly of the opinion that colts should not be altered until they are two years of age, claiming that this delay enables the animals to attain better physical development. While this may be true in certain cases, yet in the average thrifty colt, particularly of the draft breeds, the gain in certain parts of the physique is offset by pronounced undesirable characteristics which manifest themselves because of late castration. The vigorous draft colt castrated at the age of two years may possess a better developed head, neck and fore quarters than does the one operated on at a year of age, yet the croup and hind quarters of the first, are not developed in proportion to the fore quarters, there resulting an asymmetrical conformation. Because of the fact that the testicles normally descend at or soon after birth in the normal foal, in a few cases the inguinal canal remains somewhat lax and loose, making castration of a foal during his earlier months, an unsafe procedure, as hernia and even eventration may result. Under average normal conditions the best age for castrating colts is between nine and twelve months. Males of the bovine species are best castrated when \evy young, and since the operaxion apparently causes the subject a minimum degree of discomfort and there is no reason for not operating at a very early age, it is best to select the earliest convenient time. Swine also are most successfully altered when very young. Sheep and goats are not capable of withstanding surgical interference to the same extent as cattle, and are best castrated at or about two months of age. Dogs and cats are castrated merely as a matter of domestic convenience, and in the majority of instances, since these animals are kept for pets or companions, the operation is best and easiest for the subject at or about the age of six months. In the unsexing of females, reasons for operating determine in a measure, the age most suitable. Heifers are spayed, if possible, before experiencing their first estral period, and the same is true of female swine, dogs and cats. Where the operation is done by the method of Charlier, the animal needs to attain a sufficient degree of development to enable the operator to comfortably manipulate instruments within the vaginal canal. Long deferment of this operation, however, is not likely to bring at once the desired result of absence of the sexual instinct in the previously bred female of some species.

Season and Age for Castration

The season best suited for castrating depends somewhat upon climatic conditions, existent vulnerable agencies, and customs fixed because of the element of convenience necessary in proper handling of the subjects. In those latitudes where insect life or other vulnerable agencies frequently cause an unfavorable outcome, castration should be done in the spring of the year. Where animals arc sent to pasture for the spring or summer months, the operation is more conveniently done before they are turned out. In other

INTRODUCTION 13

instances, where screw worms do not abound, or where the subjects are somewhat unthrifty, it is best to castrate them during the early summer months. It seems hardly necessary to say that animals should not be exposed to adverse elements immediately after this operation, as exposure to long-continued cold rains tends to lower the vitality, decrease the powers of resistance and enhances the possibility of sequela?. However, the fallacious theory cherished by some, that colts should not be exposed to rain directly after castration, should be emphatically discouraged. Inevitably more harm is done by the well-meaning client who shelters his recently castrated colt in an unsanitary and even filthy stall than can possibly be occasioned by the heaviest downpour of rain, provided the weather is not cold. It has been found impossible for a newly castrated colt to assume the normal recumbent position when it is kept in a stable or littered barnyard without causing contamination of the surgical wounds of the scrotum. Postoperative infections have been so caused in many instances, at the expense of the reputation of the acting veterinarian, and it therefore behooves the castrator to insist positively upon having his patient kept away from all barnyard filth until the scrotal wounds have healed completely.

In castrating normal young animals that are kept under average conditions, no preoperative preparation is urgent. Where general anesthesia is employed in the handling of mature animals, or in the case of nervous stallions, food should be withheld for a sufficient length of time to minimize the danger of fermentation of ingesta which might be brought on by the attendant excitement. In certain pathological conditions where the operation is likely to consume considerable time, as in some cryptorchids, and in cases where general anesthesia is to be employed, animals should always be dieted before operating. Preoperative preparation of the surgical field varies with the case and the manner in which the technique is executed. Where a normal animal is castrated under average conditions, local preparation consists in washing with suitable solutions and rendering the field clean. In other cases, such as cryptorchid castration, a thorough cleansing of the surgical area with soap and water, drying the parts, and finally painting the skin with tincture of iodin, is a necessary precautionary measure. In the castration of swine and calves, if the parts are not soiled, no preoperative local cleansing is imperative.

Section I Castration Of Males Preliminary Measures

Selection of Instruments

In the performance of any surgical operation, every reputable surgeon has his decided preference with regard to the instruments and appliances to be used, and while it is not our purpose to recommend any particular make of instruments, we do deem it wise to call attention to the fact that there are a discov-

Fig. 1— A CASTRATING KNIFE OF A GOOD PATTERN, HAVING A SHORT BLADE WITH CONVEX CUTTING EDGE

ered few on the market the faulty construction of which makes them very undesirable for the purpose of castration.

Especially must the instrument used for this purpose be a properly designed one and of a convenient size. Castrating knives are made of the hoe blade or hooked pattern, or equipped with a rather short blade having a very convex cutting edge, and are preferably devoid of a sharp point.

For the ablation of the testicle, the emasculator is the more widely used instrument by scientific veterinarians, and so long as it is constructed in such manner that division of the cord may be effected without subsequent hemorrhage, the essentials exist, and it remains a matter of choice with the operator as to which particular style of this instrument he

2— A SUITABLE CASTRATING KNIFE HAVING A HOOKED BLADE may prefer to use. The same statement is true of the ecraseur, and as these two instruments are the principal ones employed in the castrating' operation, none others will be mentioned here.

As in the case of all surgical instruments, it is most important that they be properly cared for — kept clean and dry when not in use. It is quite impossible to keep an instrument clean after the plating has become damaged. Every veterinarian should have sufficient pride in the appearance of his equipment to keep

Fig. 3— A VERY GOOD STYLE OF EMASCULATOR WITH EXTRA ATTACHMENT TO INSURE HEMOSTASIS

it in good condition, even though it were not urgent to do so in the case of castrating instruments, to prevent possible infection, and only the practitioners who have this innate pride will tend to raise the standard of their profession. Castrating instruments should be

PEEL! MINA'KY MEASURES boiled daily when regularly used and should be kepi wrapped in a clean, sterile towel, and not loosely thrown in the soiled and more or less contaminated emergency bag. In field work the average client will inwardly, if not outwardly, appreciate the pains taken by the scrupulously exacting operator, even though he is put to some effort to procure a clean pail or basin and sterile towels for the convenience of the veterinarian,

F ; CT 4 _a SUBSTANTIAL ECRASEUR OF THE "QUICK-CHAIN"

TYPE

when the client understands that such precautions are taken for the sole purpose of lessening the danger of infection to his animals.

The veterinary student who is unfamiliar with the appearance and quality of castrating and other special instruments should refer to any complete veterinary instrument catalogue, wdiich can be readily secured from any reputable dealer.

Restraint

A thorough knowledge of practical methods of restraint of animals is very necessary in order to become skilled as a castrator. It could not he the intention of any right thinking veterinarian to employ restraint to the exclusion of anesthesia; however, oftentimes a castration operation, skillfully performed on a conscious animal, may inflict less real shock and distress to the subject than complete anesthesia used under average conditions. Proper restraint constitutes a very essential part of the operation for successful castration, and this means applies not only to the preparation of large animals but to the smaller ones as well.

Veterinary surgeons are not agreed as to the best method of procedure in the handling of larger animals in many instances, but while their opinions may differ in this, the result sought is the same, so that while one man may confine an animal in some specific way that departs radically from the manner ordinarily employed, he may, nevertheless, be a very practical and successful operator. In the handling of horse and mule colts for castration there are probably many more practitioners who cast the animals in some secure manner than there are who perform the operation with the subject in standing position. Each of the two methods has its advantages and its disadvantages, which may be summarized as follows :

The standing operation is practicable in colts that have attained sufficient size to allow for the work with a certain degree of convenience to the operator, but it is not practical and is difficult to perform in undersized subjects — particularly so in mules, where the testicle is not well developed and the cremaster muscle active in contraction. The standing operation requires less time and exertion for one skilled in its performance, but it is sometimes prolonged because of the inability of the operator and his assistant to properly control the animal, and it occasionally becomes impossible to cope successfully with certain abnormal conditions encountered, thereby necessitating interruption of the work for the purpose of casting and tying the subject so that the task may be completed. Fortunately for both operators and animals, such conditions are rarely encountered.

PRELIMINARY MEASURES

It is quite impossible to operate upon the standing animal and execute as nearly perfect a technic with respect to cleanliness as may he done upon the recumbent animal. The average operator would probably not meet with success in the handling of other animals than colts that are sufficiently tractable to be readily haltered.

All conditions and emergencies taken into considera-

Fig . 5— CASTRATION OF THE COLT IN A STANDING POSITION

The operator is close to the subject yet not contacting the animal tioii, it is evident that the performance of castration upon the standing subject would be only successfully executed by those already skilled as castrators, apt and adaptable as horsemen, and sufficiently agile to protect themselves when necessary. The operation is advised only in animals that are normal with respect to the position and development of the testicles; where there exists no hernia or other abnormal conditions which might seriously interfere with the work, and in colts having developed sufficiently to enable the operator to thoroughly execute the technic.

The matter and manner of restraint of his subjects is of great importance to the veterinarian, and he should not be wanting in proper judgment and skill to employ the most practical, the safest, and most hu-

Fig. 6-

-A PRACTICAL METHOD OF RESTRAINT FOR CASTRATING COLTS mane means in every instance. Experienced castrators have demonstrated that the wild, untamed colt is handled with the minimum degree of resistance when quickly and securely confined in recumbency, and also that the large, lethargic draft colt is more easily handled in a gentle, leisurely, yet skillful, manner. In the first instance there may be need of a lariat rope and the employment of the old simple method of "hog

PEELIMINAEY MEASURES 21

tying," whereas in the second ease the subject may be castrated while in the standing position, or he may be gently and quietly cast and confined with some practical harness. In short, it is necessary to use different methods to suit the number of varying cases.

The veterinarian should never disregard the fact that a certain amount of responsibility rests upon him in regard to the employment of untrained assistants, and their likelihood of meeting with accidents in the handling of animals. In the absence of precautionary advice, the volunteer or untrained helper may suffer painful injury, and it therefore behooves the practitioner to warn and so place his clients when they are lending assistance that he — the practitioner — may not be charged with wilful neglect in this matter. It is likewise most important that the animals placed under restraint be handled in an extremely careful manner, to prevent their becoming injured. Such forethoughtful measures will discourage attempts on the part of the client to collect indemnity in case of accidental injury or loss of the patient.

Section II Anatomy Of The Structures Directly Involved

The testicle is a structure that is composed of glandular, vascular, nervous, and fibrous tissues, and its location in the different animals varies somewhat. It is supported more or less closely to the body by means of the cremaster muscle, fibrous integuments of the cord, and by the scrotum. The cremaster muscle has its origin at the posterior portion of the inner abdominal ring, and, according to Sisson, originating from the iliac fascia near the origin of the sartorious. The distal attachment is by means of the tunica vaginalis communis.

The spermatic cord consists of fibro-areolar structure loosely enveloping arteries, veins, nerves, and the vas deferens. The spermatic artery is given off from the aorta, and the spermatic vein furnishes a means of return for the blood. Lymph vessels accompany the vein and empty into the lumbar lymph glands.

The vas deferens, which is also contained within the spermatic cord, is a continuation of the epididymis, separating itself from the vessels located in the anterior portion of the cord, as it enters the urogenital fold. The nerve supply is derived from the renal and posterior mesenteric plexuses.

The scrotum or pouch containing the testicles is composed of layers derived from the skin and other integument forming the abdominal wall, and from without inward are the skin, dartos, scrotal fascia, tunica vaginalis communis, and tunica vaginalis propria. The dartos is derived from the abdominal tunic ; the scrotal fascia is contributed by the oblique abdominal muscles ; the tunica vaginalis communis is a continuation of the parietal peritoneum ; and the tunica vaginalis propria is the mesorchium of the fetus. These coverings are not proper to the testicle, but, strictly speaking, are coverings usually considered as forming the scrotum.

The proper covering of the testicle is the fibrous, inelastic, closely-investing tunica albuginea, which is not directly attached even to the tunica vaginalis propria, In the immediate region of the scrotum there is to be found in some cases in colts an abnormal development of branches of the external pudic veins forming plexuses. This is common in cryptorchids.

There is much difference in the comparative size of the testicles in the various domestic animals. Bulls, sheep and goats have comparatively large testicles, which are supported in the sub-pubic region in a pendent manner, exposing these glands to injury from ballotment between the thighs or from actual violence in many other ways. The testicles of the boar are comparatively large but closely invested by the scrotum, and situated in the external perineal region in such manner that they are well protected. In the horse the testicles are comparatively smaller than are those of the animals aforementioned, supported rather more closely to the body in the sub-pubic region and ordinarily not subject to injury except from chafing, this occurring more often in light harness horses put at fast work.

Section III Methods Of Castration

In the castration of animals the practicability of any given modus operandi can only be judged according to the convenience of the veterinarian and the possible difficulties to be encountered in varying cases. Ablation of the testicle being the essential object of the operation, assuredly, then, it behooves the surgeon to accomplish this result in the most practical manner possible, with the least discomfort and danger to his subject and to himself.

A consideration in the performance of this operation is the danger of hemorrhage, and because of this possibility being greater in certain animals, the instrument to be used should be selected accordingly. In subjects prone to suffer hemorrhage, the employment of the ecraseur, the emasculator, ligatures, or even the wood clamp, is indicated ; but for all practical purposes where hemorrhage is improbable, removal of the testicles may be safely and immediately accomplished by the use of the knife. The use of the ecraseur or emasculator in the castration of a weanling pig, for instance, is impractical, and is not a favorable choice for the operator. In animals where there exists some possibility of hemorrhage, the knife may be employed in such a manner that the tissues severed are scraped and not keenly divided, and a moderate degree of "unlimited" torsion of the spermatic cord — twisting it round and round — and then dividing the tissues by scraping, lessens the danger of hemorrhage.

Histologically considered, the tunica intima of arteries is the most delicate layer of the three, and where any sort of manipulation of an artery results in injury to this innermost layer, retraction of the tissue follows. With such retraction and contusion, the lumen of the vessel is materially lessened, and coagulation of blood is hastened. This inner tissue of the arterial wall is the least resistant and will be divided before the outer structures are crushed; therefore any instrument that will effect the division of the tissue surely, and cause sufficient contusion to insure coagulation of arterial blood, will serve for the safe removal of the testicle.

While the term castration only refers to the ablation of the testicle, other means of rendering animals sterile are sometimes resorted to. The secreting power of the testicles may be destroyed and still leave them in situ. These painful methods are employed in countries where the production of castration wounds are inadvisable because of the possibilities of infection resulting in tetanus or other dangerous maladies. The destruction of the secreting power of the organs may be brought about by a subcutaneous torsion of the testicles by digital manipulation — the testicles being placed in a position that causes complete obstruction of the circulation and resulting in aseptic inflammation and eventual atrophy of the glands.

In animals having a pendent scrotum, the spermatic cord may be crushed subcutaneously between the edges of pieces of wood or other blunt objects, which will ultimately cause atrophy of the testicles and sterility; or a ligature applied above the constricted portion of the scrotum, situated above the testicles, will in about two weeks cause sloughing of the scrotum. But such barbarous methods inflict much suffering on

METHODS OF CASTRATION the subject, and while they have been necessary in some sections for local reasons, to the scientific and humane mind they should be termed obsolete and unworthy of consideration.

Castration operations may be regarded under tw T o general headings with certain modifications, and are

7— THE "COVERED OPERATION," SHOWING EMASCULA- TION OF THE TESTICLE AND ITS INTACT VAGINAL COVERINGS to be classed as the uncovered operation and the covered operation.

The uncovered operation is the one usually employed and is the more practical in the various animals when the subjects are in a normal condition. This operation consists in the exposure of the testicle proper by means of an incision through the scrotum, such incision penetrating the skin, dartos, scrotal fascia, and both layers of the vaginal tunic, thereby exposing the testicle within its own adherent covering and subsequent ablation of the gland.

The covered operation is indicated in cases of scrotal or inguinal hernia and is executed by incising the skin and dartos and by breaking down the scrotal fascia, thus exposing the tunica vaginalis communis, but not perforating it. By careful blunt dissection in the process of severing the attachments of the scrotal fascia, the operator is enabled to cause protrusion of the testicle confined in its own proper covering plus both layers of the vaginal tunic, providing for the application of a clamp, or ligature, en masse, before the actual ablation of the testicle is effected.

SECTION IV Normal Colt

Since there are more colts castrated and restrained in recumbency by means of some sort of harness, this shall be described as the principal method of restraint. After having cast and securely tied the colt on its left side (for the right-handed operator), an assistant is stationed at its head to prevent the animal doing itself injury. The tail is then either held under the foot of the operator or secured in some practical manner to preclude its being thrown over the surgical area.

Preparation of Subject

The surgical field should first be cleansed of any dry dust or particles of filth which may have been thrown there during the resisting struggles of the animal. Having at hand, in a clean vessel, about a gallon of suitable antiseptic solution (a one per cent lysol solution, or formalin one-fifth of one per cent), the scrotum is then rinsed off thoroughly.

Operative Procedure

The castrating knife and emasculator should be in readiness. The lowermost testicle is seized between the thumb and finger of the left hand of the operator, and a bold incision made parallel with the median raphe for a distance sufficient to insure the free drainage of the wound after the operation has been completed.

This incision, skillfully made, reaches through all of the scrotal wall down to the testicle, yet should not penetrate the testicle proper nor injure the gland. Care in this particular not only minimizes the pain •of the subject but in the mature animal obviates the otherwise inevitable result of hemorrhage. If done with care, a moderate degree of traction may be exerted upon the testicle to cause relaxation of the cr'emaster muscle, but undue force used in such cases may result in rupture not only to the attachments of the cremaster muscle, but to the spermatic vessels as well, and this occurring within the abdominal cavity causes hemorrhage into the peritoneal cavity, with fatal results. In some cases the power of contraction of the cremaster muscle is so well developed that it resists the efforts of the operator to draw out the cord, and in such cases it is wise to work slowly, holding the cord for a sufficient length of time until muscular relaxation occurs. The use of quick force is to be avoided, as said before. The emasculator is then applied as close to the scrotum as possible, and the cord and the lower part of the vaginal tunic is severed there. Hemostasis is not aided by the slow closing of the emasculator, and because this deliberation only adds to the pain of the operation, it should also be avoided.

Subsequent to emasculation, the scrotal wound may be enlarged to prevent the retention of any wound secretion or infective disturbances. Another method of providing for the free escape of wound secretion consists in the making of an incision through the scrotal wall beginning at the median portion of the margin, carrying the incision away at a right angle from the median raphe for a distance of about an inch or an inch and a half.