Chapter IX: Part 9

The excess of mineral matter in a specimen of urine unquestionably contributes to the formation of calculi, just as a solution of such matters out of the body is increasingly disposed to throw them down in the form of crystals as it becomes more concentrated and approaches nearer to the condition of saturation. Hence, in considering the causes of calculi we can not ignore the factor of an excessive ration, rich in mineral matters and in carbonaceous matters (the source of carbonates and much of the oxalates), nor can we overlook the concentration of the urine that comes from dry feed and privation of water, or from the existence of fever which causes suspension of the secretion of water. In these cases, at least the usual quantity of solids is thrown off by the kidneys, and as the water is diminished there is danger of its approaching the point of supersaturation, when the dissolved solids must necessarily be thrown down. Hence, calculi are more common in stable horses fed on dry grain and hay, in those denied a sufficiency of water or that have water supplied irregularly, in those subjected to profuse perspiration (as in summer), and in those suffering from a watery diarrhea. On the whole, calculi are most commonly found in winter, because the horses are then on dry feeding, but such dry feeding is even more conducive to them in summer when the condition is aggravated by the abundant loss of water by the skin.

In the same way the extreme hardness of the water in certain districts must be looked upon as contributing to the concentration of the urine and correspondingly to the production of stone. The carbonates, sulphates, etc., of lime and magnesia taken in the water must be again thrown out, and just in proportion as these add to the solids of the urine they dispose it to precipitate its least soluble constituents. Thus the horse is very subject to calculi on certain limestone soils, as over the calcareous formations of central and western New York, Pennsylvania, and Ohio, in America; of Norfolk, Suffolk, Derbyshire, Shropshire, and Gloucestershire, in England; of Poitou and Landes, in France; and Munich, in Bavaria.

The saturation of the urine from any or all of these conditions can only be looked on as an auxiliary cause, however, and not as in itself an efficient one, except on the rarest occasions. For a more direct and immediate cause we must look to the organic matter which forms a large proportion of all urinary calculi. This consists of mucus, albumen, pus, hyaline casts of the uriniferous tubes, epithelial cells, blood, etc., mainly agents that belong to the class of colloid or noncrystalline bodies. A horse may live for months and years with the urine habitually of a high density and having the mineral constituents in excess without the formation of stone or gravel; again, one with dilute urine of low specific gravity will have a calculus.

Rainey, Ord, and others furnish the explanation. They not only show that a colloid body, like mucus, albumen, pus, or blood, determined the precipitation or the crystalline salts in the solution, but they determined the precipitation in the form of globules, or spheres, capable of developing by further deposits into calculi. Heat intensifies this action of the colloids, and a colloid in a state of decomposition is specially active. The presence, therefore, of developing fungi and bacteria must be looked upon as active factors in causing calculi.

In looking, therefore, for the immediate causes of calculi we must consider especially all those conditions which determine the presence of albumen, blood, and excess of mucus, pus, etc., in the urine. Thus diseases of distant organs leading to albuminuria, diseases of the kidneys and urinary passages causing the escape of blood or the formation of mucus or pus, become direct causes of calculi. Foreign bodies of all kinds in the bladder or kidney have long been known as determining causes of calculi and as forming the central nucleus. This is now explained by the fact that these bodies are liable to carry bacteria into the passages and thus determine decomposition, and they are further liable to irritate the mucous membrane and become enveloped in a coating of mucus, pus, and perhaps blood.

The fact that horses, especially on the magnesian limestones, the same districts in which they suffer from goiter, appear to suffer from calculi may be similarly explained. The unknown poison which produces goiter presumably leads to such changes in the blood and urine as will furnish the colloid necessary for precipitation of the urinary salts in the form of calculi.

CLASSIFICATION OF URINARY CALCULI.

These have been named according to the place where they are found, renal (kidney), ureteric (ureter), vesical (bladder), urethral (urethra), and preputial (sheath, or prepuce). They have been otherwise named according to their most abundant chemical constituent, carbonate of lime, oxalate of lime, and phosphate of lime calculi. The stones formed of carbonates or phosphates are usually smooth on the surface, though they may be molded into the shape of the cavity in which they have been formed; thus those in the pelvis of the kidney may have two or three short branchlike prolongations, while those in the bladder are round, oval, or slightly flattened upon each other. Calculi containing oxalate of lime, on the other hand, have a rough, open, crystalline surface, which has gained for them the name of mulberry calculi, from a supposed resemblance to that fruit. These are usually covered with more or less mucus or blood, produced by the irritation of the mucous membrane by their rough surfaces. The color of calculi varies from white to yellow and deep brown, the shades depending mainly on the amount of the coloring matter of blood, bile, or urine which they may contain.

_Renal calculi._--These may consist of minute, almost microscopic, deposits in the uriniferous tubes in the substance of the kidney, but more commonly they are large masses and lodged in the pelvis. The larger calculi, sometimes weighing 12 to 24 ounces, are molded in the pelvis of the kidney into a cylindroid mass, with irregular rounded swellings at intervals. Some have a deep brown, rough, crystalline surface of oxalate of lime, while others have a smooth, pearly white aspect from carbonate of lime. A smaller calculus, which has been called coralline, is also cylindroid, with a number of brown, rough, crystalline oxalate of lime branches and whitish depressions of carbonate. These vary in size from 15 grains to nearly 2 ounces. Less frequently are found masses of very hard, brownish white, rounded, pealike calculi. These are smoother, but on the surface crystals of oxalate of lime may be detected with a lens. Some renal calculi are formed of more distinct layers, more loosely adherent to one another, and contain an excess of mucus, but no oxalate of lime. Finally, a loose aggregation of small masses, forming a very friable calculus, is found of all sizes within the limits of the pelvis of the kidney. These, too, are in the main carbonate of lime (84 to 88 per cent) and without oxalate.

Symptoms of renal calculi are violent, colicky, pains, appearing suddenly, very often in connection with exhausting work or the drawing of specially heavy loads, and in certain cases disappearing with equal suddenness. The nature of the colic becomes more manifest if it is associated with stiffness of the back and hind limbs, frequent passage of urine, and, above all, the passage of gravel with the urine, especially at the time of the access of relief. The passage of blood and pus in the urine is equally significant. If the irritation of the kidney goes on to active inflammation, then the symptoms of nephritis are added.

_Ureteric calculi._--These are so called because they are found in the passage leading from the kidney to the bladder. They are simply small, renal calculi which have escaped from the pelvis of the kidney and have become arrested in the ureter. They give rise to symptoms almost identical with those of renal calculi, with this difference, that the colicky pains, caused by the obstruction of the ureter by the impacted calculus, are more violent, and if the calculus passes on into the bladder the relief is instantaneous and complete. If the ureter is completely blocked for a length of time, the retained urine may give rise to destructive inflammation in the kidney, which may end in the entire absorption of that organ, leaving only a fibrous capsule containing an urinous fluid. If both the ureters are similarly blocked, the animal will die of uremic poisoning.

_Treatment of renal and ureteric calculi._--Treatment is unsatisfactory, as it is only the small calculi that can pass through the ureters and escape into the bladder. This may be favored by agents which will relax the walls of the ureters by counteracting their spasm and even lessening their tone, and by a liberal use of water and watery fluids to increase the urine and the pressure upon the calculus from behind. One or two ounces of laudanum, or 2 drams of extract of belladonna, may be given and repeated as it may be necessary, the relief of the pain being a fair criterion of the abating of the spasm. To the same end use warm fomentations across the loins, and these should be kept up persistently until relief is obtained. These act not only by soothing and relieving the spasm and inflammation, but they also favor the freer secretion of a more watery urine, and thus tend to carry off the smaller calculi. To accomplish this object further give cool water freely, and let the feed be only such as contains a large proportion of liquid, gruels, mashes, turnips, beets, apples, pumpkins, ensilage, succulent grasses, etc. If the acute stage has passed and the presence of the calculus is manifested only by the frequent passage of urine with gritty particles, by stiffness of the loins and hind limbs, and by tenderness to pressure, the most promising resort is a long run at pasture where the grasses are fresh and succulent. The long-continued secretion of a watery urine will sometimes cause the breaking down of a calculus, as the imbibition of the less dense fluid by the organic, spongelike framework of the calculus causes it to swell and thus lessens its cohesion. The same end is sought by the long-continued use of alkalies (carbonate of potassium), and of acids (muriatic), each acting in a different way to alter the density and cohesion of the stone. It is only exceptionally, however, that any one of these methods is entirely satisfactory. If inflammation of the kidneys develops, treat as advised under that head.

_Stone in the bladder (vesical calculus, or cystic calculus)._--These may be of any size up to over a pound in weight. One variety is rough and crystalline and has a yellowish-white or deep-brown color. These contain about 87 per cent carbonate of lime, the remainder being carbonate of magnesia, oxalate of lime, and organic matter. The phosphatic calculi are smooth, white and formed of thin, concentric layers of great hardness extending from the nucleus outward. Besides the phosphate of lime they contain the carbonates of lime and magnesia and organic matter. In some cases the bladder contains and may be even distended by a soft, pultaceous mass made up of minute, round granules of carbonates of lime and magnesia. This, when removed and dried, makes a firm, white, and stony mass. Sometimes this magma is condensed into a solid mass in the bladder by reason of the binding action of the mucus and other organic matter, and then forms a conglomerate stone of nearly uniform consistency and without stratification.

_Symptoms of stone in the bladder._--The symptoms of stone in the bladder are more obvious than those of renal calculus. The rough, mulberry calculi especially lead to irritation of the mucous membrane and frequent passing of urine in small quantities and often mingled with mucus or blood or containing minute, gritty particles. At times the flow is suddenly arrested, though the animal continues to strain and the bladder is not quite emptied. In the smooth, phosphatic variety the irritation is much less marked and may even be altogether absent. With the pultaceous deposit in the bladder there is incontinence of urine, which dribbles away continually and keeps the hair on the inner side of the thighs matted with soft magma. In all cases alike the calculus may be felt by the examination of the bladder with the oiled hand in the rectum. The pear-shaped outline of the bladder can be felt beneath, and within it the solid, oval body. It is most easily recognized if the organ is half full of liquid, as then it is not grasped by the contracting walls of the bladder, but may be made to move from place to place in the liquid. If a pultaceous mass is present it has a soft, doughy feeling, and when pressed an indentation is left.

In the mare the hard stone may be touched by the finger introduced through the short urethra.

_Treatment of stone in the bladder._--The treatment of stone in the bladder consists in the removal of the offending body; in the mare this is easily effected with the lithotomy forceps. These are slightly warmed and oiled, and carried forward along the floor of the passage of the vulva for 4 inches, when the orifice of the urethra will be felt exactly in the median line. Through this the forceps are gradually pushed with gentle, oscillating movement until they enter the bladder and strike against the hard surface of the stone. The stone is now grasped between the blades, care being taken to include no loose fold of the mucous membrane, and it is gradually withdrawn with the same careful, oscillating motions as before. Facility and safety in seizing the stone will be greatly favored by having the bladder half full of liquid, and if necessary one oiled hand may be introduced into the rectum or vagina to assist. The resulting irritation may be treated by an injection of laudanum, 1 ounce in a pint of tepid water.

The removal of the stone in the horse is a much more difficult proceeding. It consists in cutting into the urethra just beneath the anus and introducing the lithotomy forceps from this forward into the bladder, as in the mare. It is needful to distend the urethra with tepid water or to insert a sound or catheter to furnish a guide upon which the incision may be made, and in case of a large stone it may be needful to enlarge the passage by cutting in a direction upward and outward with a probe-pointed knife, the back of which is slid along in the groove of a director until it enters the bladder.

The horse may be operated upon in the standing position, being simply pressed against the wall by a pole passed from before backward along the other side of the body. The tepid water is injected into the end of the penis until it is felt to fluctuate under the pressure of the finger, in the median line over the bone just beneath the anus. The incision is then made into the center of the fluctuating canal, and from above downward. When a sound or catheter is used as a guide it is inserted through the penis until it can be felt through the skin at the point where the incision is to be made beneath the anus. The skin is then rendered tense by the thumb and fingers of the left hand pressing on the two sides of the sound, while the right hand, armed with a scalpel, cuts downward onto the catheter. This vertical incision into the canal should escape wounding any important blood vessel. It is in making the obliquely lateral incision in the subsequent dilatation of the urethra and neck of the bladder that such danger is to be apprehended.

If the stone is too large to be extracted through the urethra, it may be broken down with the lithotrite and extracted piecemeal with the forceps. The lithotrite is an instrument composed of a straight stem bent for an inch or more to one side at its free end so as to form an obtuse angle, and having on the same side a sliding bar moving in a groove in the stem and operated by a screw so that the stone may be seized between the two blades at its free extremity and crushed again and again into pieces small enough to extract. Extra care is required to avoid injury to the urethra in the extraction of the angular fragments, and the gravel or powder that can not be removed in this way must be washed out, as advised below.

When a pultaceous magma of carbonate of lime accumulates in the bladder it must be washed out by injecting water through a catheter by means of a force pump or a funnel, shaking it up with the hand introduced through the rectum and allowing the muddy liquid to flow out through the tube. This is to be repeated until the bladder is empty and the water come away, clear. A catheter with a double tube is sometimes used, the injection passing in through the one tube and escaping through the other. The advantage is more apparent than real, however, as the retention of the water until the magma has been shaken up and mixed with it hastens greatly its complete evacuation.

To prevent the formation of a new deposit any fault in feeding (dry grain and hay with privation of water, excess of beans, peas, wheat bran, etc.) and disorders of stomach, liver, and lungs must be corrected. Give abundance of soft drinking water, encouraging the animal to drink by a handful of salt daily. Let the feed be laxative, consisting largely of roots, apples, pumpkins, ensilage, and give daily in the drinking water a dram of either carbonate of potash or soda. Powdered gentian root (3 drams daily) will also serve to restore the tone of the stomach and system at large.

_Urethral calculus (stone in the urethra)._--This is less frequent in horses than in cattle and sheep, owing to the larger size of the urethra in the horse and the absence of the <b>S</b>-shaped curve and vermiform appendix. The calculi arrested in the urethra are never formed there, but consist of cystic calculi which have been small enough to pass through the neck of the bladder, but are too large to pass through the whole length of the urethra and escape. Such calculi therefore are primarily formed either in the bladder or kidney, and have the chemical composition of the other calculi found in those organs. They may be arrested at any point of the urethra, from the neck of the bladder back to the bend of the tube beneath the anus, and from that point down to the extremity of the penis. I have found them most frequently in the papilla on the extreme end of the penis, and immediately behind this.

_Symptoms of urethral calculus._--The symptoms are violent straining to urinate, but without any discharge, or with the escape of water in drops only. Examination of the end of the penis will detect the swelling of the papilla or the urethra behind it, and the presence of a hard mass in the center. A probe inserted into the urethra will strike against the gritty calculus. If the stone has been arrested higher up, its position may be detected as a small, hard, sensitive knot on the line of the urethra, in the median line of the lower surface of the penis, or on the floor of pelvis in the median line from the neck of the bladder back to the bend of the urethra beneath the anus. In any case the urethra between the neck of the bladder and the point of obstruction is liable to be filled with fluid, and to feel like a distended tube, fluctuating on pressure.

_Treatment of urethral calculus_ may be begun by an attempt to extract the calculi by manipulation of the papilla on the end of the penis. This failing, the calculus may be seized with a pair of fine-pointed forceps and withdrawn from the urethra; or, if necessary, a probe-pointed knife may be inserted and the urethra slightly dilated, or even laid open, and the stone removed. If the stone has been arrested higher up it must be extracted by a direct incision through the walls of the urethra and down upon the nodule. If in the free (protractile) portion of the penis, that organ is to be withdrawn from its sheath until the nodule is exposed and can be incised. If behind the scrotum, the incision must be made in the median line between the thighs and directly over the nodule, the skin having been rendered tense by the fingers and thumb of the left hand. If the stone has been arrested in the intrapelvic portion of the urethra, the incision must be made beneath the anus and the calculus extracted with forceps, as in stone in the bladder. The wound in the urethra may be stitched up, and usually heals slowly but satisfactorily. Healing will be favored by washing two or three times daily with a solution of a teaspoonful of carbolic acid in a pint of water.

_Preputial calculus (calculus in the sheath, or bilocular cavity)._--These are concretions in the sheath, though the term has been also applied to the nodule of sebaceous matter which accumulates in the blind pouches (bilocular cavity) by the sides of the papilla on the end of the penis. Within the sheath the concretion may be a soft, cheesy-like sebaceous matter, or a genuine calculus of carbonate, oxalate, phosphate and sulphate of lime, carbonate of magnesia, and organic matter. These are easily removed with the fingers, after which the sheath should be washed out with castile soap and warm water and smeared with sweet oil.

DISEASES OF THE GENERATIVE ORGANS.

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

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

CONGESTION AND INFLAMMATION OF THE TESTICLES, OR ORCHITIS.

In the prime of life, in vigorous health, and on stimulating feed, stallions are subject to congestion of the testicles, which become swollen, hot, and tender, but without any active inflammation. A reduction of the grain in the feed, the administration of 1 or 2 ounces of Glauber's salt daily in the feed, and the bathing of the affected organs daily with tepid water or alum water will usually restore them to a healthy condition.

When the factors producing congestion are extraordinarily potent, when there has been frequent copulation and heavy grain feeding, when the weather is warm and the animal has had little exercise, and when the proximity of other horses or mares excites the generative instinct without gratification, this congestion may grow to actual inflammation. Among the other causes of orchitis are blows and penetrating wounds implicating the testicles, abrasions of the scrotum by a chain or rope passing inside the thigh, contusions and frictions on the gland under rapid paces or heavy draft, compression of the blood vessels of the spermatic cord by the inguinal ring under the same circumstances, and, finally, sympathetic disturbance in cases of disease of the kidneys, bladder, or urethra. Stimulants of the generative functions, like rue, savin, tansy, cantharides, and damiana, may also be accessory causes of congestion and inflammation. Finally, certain specific diseases, like dourine, glanders, and tuberculosis, localized in the testicles, will cause inflammation.

_Symptoms._--Apart from actual wounds of the parts, the symptoms of orchitis are swelling, heat, and tenderness of the testicles, straddling with the hind legs alike in standing and walking, stiffness and dragging of the hind limbs or of the limb on the affected side, arching of the loins, abdominal pain, manifested by glancing back at the flank, more or less fever, elevated body temperature, accelerated pulse and breathing, lack of appetite, and dullness. In bad cases the scanty urine may be reddish and the swelling may extend to the skin and envelopes of the testicle, which may become thickened and doughy, pitting on pressure. The swelling may be so much greater in the convoluted excretory duct along the upper border of the testicle as to suggest the presence of a second stone. Even in the more violent attacks the intense suffering abates somewhat on the second or third day. If it lasts longer, it is liable to give rise to the formation of matter (abscess). In exceptional cases the testicle is struck with gangrene, or death. Improvement may go on slowly to complete recovery, or the malady may subside into a subacute and chronic form with induration. Matter (abscess) may be recognized by the presence of a soft spot, where pressure with two fingers will detect fluctuation from one to the other. When there is liquid exudation into the scrotum, or sac, fluctuation may also be felt, but the liquid can be made out to be around the testicle and can be pressed up into the abdomen through the inguinal canal. When abscess occurs in the cord the matter may escape into the scrotal sac and cavity of the abdomen and pyemia may follow.

_Treatment_ consists in perfect rest and quietude, the administration of a purgative (1 to 1-1/2 pounds Glauber's salt), and the local application of an astringent lotion (acetate of lead 2 drams, extract of belladonna 2 drams, and water 1 quart) upon soft rags or cotton wool, kept in contact with the part by a suspensory bandage. This bandage, of great value for support, may be made nearly triangular and tied to a girth around the loins and to the upper part of the same surcingle by two bands carried backward and upward between the thighs. In severe cases scarifications one-fourth inch deep serve to relieve vascular tension. When abscess is threatened its formation may be favored by warm fomentations or poultices, and on the occurrence of fluctuation the knife may be used to give free escape to the pus. The resulting cavity may be injected daily with a weak carbolic-acid lotion, or salol may be introduced. The same agents may be used on a gland threatened with gangrene, but its prompt removal by castration is to be preferred, antiseptics being applied freely to the resulting cavity.

SARCOCELE.

This is an enlarged and indurated condition of the gland, resulting from chronic inflammation, though it is often associated with a specific deposit, like glanders. In this condition the natural structure of the gland has given place to embryonal tissue (small, round cells, with a few fibrous bundles), and its restoration to health is very improbable. Apart from active inflammation, it may increase very slowly. The diseased testicle is enlarged, firm, nonelastic, and comparatively insensible. The skin of the scrotum is tense, and it may be edematous (pitting on pressure), as are the deeper envelopes and spermatic cord. If liquid is present in the sac, the symptoms are masked somewhat. As it increases it causes awkward, straddling, dragging movement of the hind limbs, or lameness on the affected side. The spermatic cord often increases at the same time with the testicle, and the inguinal ring being thereby stretched and enlarged, a portion of intestine may escape into the sac, complicating the disease with hernia.

The only rational and effective treatment is castration, and when the disease is specific (glanders, tuberculosis), even this may not succeed.

HYDROCELE, OR DROPSY OF THE SCROTUM.

This may be merely an accompaniment of dropsy of the abdomen, the cavity of which is continuous with that of the scrotum in horses. It may be the result, however, of local disease in the testicle, spermatic cord, or walls of the sac.

_Symptoms._--The symptoms are enlargement of the scrotum, and fluctuation under the fingers, the testicle being recognized as floating in water. By pressure the liquid is forced, in a slow stream and with a perceptible thrill, into the abdomen. Sometimes the cord or the scrotum is thickened and pits on pressure.

_Treatment_ may be the same as for ascites, yet when the effusion has resulted from inflammation of the testicle or cord, astringent applications (chalk and vinegar) may be applied to these. Then, if the liquid is not reabsorbed under diuretics and tonics, it may be drawn off through the nozzle of a hypodermic syringe which has been first passed through carbolic acid. In geldings it is best to dissect out the sacs.

VARICOCELE.

This is an enlargement of the venous network of the spermatic cord, and gives rise to general thickening of the cord from the testicle up to the ring. The same astringent dressings may be tried as in hydrocele, and, this failing, castration may be resorted to.

ABNORMAL NUMBER OF TESTICLES.

Sometimes one or both testicles are wanting; in most such cases, however, they are merely partially developed, and retained in the inguinal canal or abdomen (cryptorchid). In rare cases there may be a third testicle, the animal becoming to this extent a double monster. Teeth, hair, and other indications of a second fetus have likewise been found in the testicle or scrotum.

DEGENERATION OF THE TESTICLES.

The testicles may become the seat of fibrous, calcareous, fatty, cartilaginous, or cystic degeneration, for all which the appropriate treatment is castration. They also become the seat of cancer, glanders, or tuberculosis, and castration is requisite, though with less hope of arresting the disease. Finally, they may become infested with cystic tapeworms or the agamic stage of a strongyle (_Strongylus edentatus_).

WARTS ON THE PENIS.

These are best removed by twisting them off, using the thumb and forefinger. They may also be cut off with scissors and the roots cauterized with nitrate of silver.

DEGENERATION OF PENIS (PAPILLOMA, OR EPITHELIOMA).

The penis of the horse is subject to great cauliflower-like growths on its free end, which extend back into the substance of the organ, obstruct the passage of urine, and cause very fetid discharges. The only resort is to cut them off, together with whatever portion of the penis has become diseased and indurated. The operation, which should be performed by a veterinary surgeon, consists in cutting through the organ from its upper to its lower aspect, twisting or tying the two dorsal arteries, and leaving the urethra longer by half an inch to 1 inch than the adjacent structures.

EXTRAVASATION OF BLOOD IN THE PENIS.

As the result of kicks, blows, or of forcible striking of the penis on the thighs of the mare which it has failed to enter, the penis may become the seat of effusion of blood from one or more ruptured blood vessels. This gives rise to a more or less extensive swelling on one or more sides, followed by some heat and inflammation, and on recovery a serious curving of the organ. The treatment in the early stages may be the application of lotions, of alum, or other astringents, to limit the effusion and favor absorption. The penis should be suspended in a sling.

PARALYSIS OF THE PENIS.

This results from blows and other injuries, and also in some cases from too frequent and exhausting service. The penis hangs from the sheath, flaccid, pendulous, and often cold. The passage of urine occurs with lessened force, and especially without the final jets. In cases of local injury the inflammation should first be subdued by astringent and emollient lotions, and in all cases the system should be invigorated by nourishing diet, while 30-grain doses of nux vomica are given twice a day. Finally, a weak current of electricity sent through the penis from just beneath the anus to the free portion of the penis, continued for 10 or 15 minutes and repeated daily, may prove successful.

SELF-ABUSE, OR MASTURBATION.

Some stallions acquire this vicious habit, stimulating the sexual instinct to the discharge of semen by rubbing the penis against the belly or between the fore limbs. The only remedy is a mechanical one, the fixing of a net under the penis in such fashion as to prevent the extension of the penis or so prick the organ as to compel the animal to desist through pain.

DOURINE.

This disease is discussed in the chapter on "Infectious Diseases."

CASTRATION.

CASTRATION OF STALLIONS.

This is usually done at 1 year old, but may be accomplished at a few weeks old at the expense of an imperfect development of the fore parts. The simplicity and safety of the operation are greatest in the young. The delay till 2, 3, or 4 years old will secure a better development and carriage of the fore parts. The essential part of castration is the safe removal or destruction of the testicle and the arrest or prevention of bleeding from the spermatic artery round in the anterior part of the cord. Into the many methods of accomplishing this limited space forbids us to enter here, so that only the method most commonly adopted, castration by clamps, will be noticed. The animal having been thrown on his left side, and the right hind foot drawn up on the shoulder, the exposed scrotum, penis, and sheath are washed with soap and water, any concretion of sebum being carefully removed from the bilocular cavity in the end of the penis. The left spermatic cord, just above the testicle, is now seized in the left hand, so as to render the skin tense over the stone, and the right hand, armed with the knife, makes an incision from before backward, about three-fourths of an inch from and parallel to the median line between the thighs, deep enough to expose the testicle and long enough to allow that organ to start out through the skin. At the moment of making this incision the left hand must grasp the cord very firmly, otherwise the sudden retraction of the testicle by the cremaster muscle may draw it out of the hand and upward through the canal and even into the abdomen. In a few seconds, when the struggle and retraction have ceased, the knife is inserted through the cord, between its anterior and posterior portions, and the latter, the one which the muscle retracts, is cut completely through. The testicle will now hang limp, and there is no longer any tendency to retraction. It should be pulled down until it will no longer hang loose below the wound and the clamps applied around the still attached portion of the cord, close up to the skin. The clamps, which may be made of any tough wood, are grooved along the center of the surfaces opposed to each other, thereby fulfilling two important indications--(a) enabling the clamps to hold more securely and (b) providing for the application of an antiseptic to the cord. For this purpose a dram of sulphate of copper may be mixed with an ounce of vaseline and pressed into the groove in the face of each clamp. In applying the clamp over the cord it should be drawn so close with pincers as to press out all blood from the compressed cord and destroy its vitality, and the cord applied upon the compressing clamps should be so hard-twined that it will not stretch later and slacken the hold. When the clamp has been fixed the testicle is cut off one-half to 1 inch below it, and the clamp may be left thus for 24 hours; then, by cutting the cord around one end of the clamp, the latter may be opened and the stump liberated without any danger of bleeding. Should the stump hang out of the wound it should be pushed inside with the finger and left there. The wound should begin to discharge white matter on the second day in hot weather or the third in cold, and from that time a good recovery may be expected.

The young horse suffers less from castration than the old, and very rarely perishes. Good health in the subject is all important. Castration should never be attempted during the prevalence of strangles, influenza, catarrhal fever, contagious pleurisy, bronchitis, pneumonia, purpura hemorrhagica, or other specific disease, nor on subjects that have been kept in close, ill-ventilated, filthy buildings, where the system is liable to have been charged with putrid bacteria or other products. Warm weather is to be preferred to cold, but the fly time should be avoided or the flies kept at a distance by the application of a watery solution of tar, carbolic acid, or camphor to the wound.

CASTRATION OF CRYPTORCHIDS (RIDGLINGS).

This is the removal of a testicle or testicles that have failed to descend into the scrotum, but have been detained in the inguinal canal or inside the abdomen. The manipulation requires an accurate anatomical knowledge of the parts, and special skill, experience, and manual dexterity, and can not be made clear to the unprofessional mind in a short description. It consists, however, in the discovery and removal of the missing gland by exploring through the natural channel (the inguinal canal), or, in case it is absent, through the inguinal ring or through an artificial opening made in front and above that channel between the abdominal muscles and the strong fascia on the inner side of the thigh (Poupart's ligament). Whatever method is used, the skin, hands, and instruments should be rendered aseptic with a solution of mercuric chlorid 1 part, water 2,000 parts (a carbolic-acid lotion for the instruments), and the spermatic cord is best torn through by the ecraseur. In many such cases, too, it is desirable to sew up the external wound and keep the animal still, to favor healing of the wound by adhesion.

CONDITIONS FOLLOWING CASTRATION.

_Pain after castration._--Some horses are pained and very restless for several hours after castration, and this may extend to cramps of the bowels and violent colic. This is best kept in check by carefully rubbing the patient dry when he rises from the operation, and then leading him in hand for some time. If the pain still persists a dose of laudanum (1 ounce for an adult) may be given.

_Bleeding after castration._--Bleeding from the wound in the scrotum and from the little artery in the posterior portion of the spermatic cord always occurs, and in warm weather may appear to be quite free. It scarcely ever lasts, however, more than 15 minutes, and is easily checked by dashing cold water against the part.

Bleeding from the spermatic artery in the anterior part of the cord may be dangerous when due precaution has not been taken to prevent it. In such case the stump of the cord should be sought for and the artery twisted with artery forceps or tied with a silk thread. If the stump can not be found, pledgets of tow wet with tincture of muriate of iron may be stuffed into the canal to favor the formation of clot and the closure of the artery.

_Strangulated spermatic cord._--If in castration the cord is left too long, so as to hang out of the wound, the skin wound in contracting grasps and strangles it, preventing the free return of blood and causing a steadily advancing swelling. In addition the cord becomes adherent to the lips of the wound in the skin, whence it derives an increased supply of blood, and is thereby stimulated to more rapid swelling. The subject walks stiffly, with a straddling gait, loses appetite, and has a rapid pulse and high fever. Examination of the wound discloses the partial closure of the skin wound and the protrusion, from its lips, of the end of the cord, red, tense, and varying in size from a hazelnut upward. If there is no material swell and little protrusion, the wound may be enlarged with the knife and the end of the cord broken loose from any connection with the skin and pushed up inside. If the swelling is larger, the mass constitutes a tumor and must be removed. (See below.)

_Swelling of the sheath, penis, and abdomen._--This occurs in certain unhealthy states of the system, in unhealthful seasons, as the result of operating without cleansing the sheath and penis, or of keeping the subject in a filthy, impure building, as the result of infecting the wound by hands or instruments bearing septic bacteria, or as the result of premature closure of the wound, and imprisonment of matter.

Pure air and cleanliness of groin and wound are to be obtained. Antiseptics, like the mercuric-chlorid lotion (1 part to 2,000) are to be applied to the parts; the wound, if closed, is to be opened anew, any accumulated matter or blood washed out, and the antiseptic liquid freely applied. The most tense or dependent parts of the swelling in sheath or penis, or beneath the belly, should be pricked at intervals of 3 or 4 inches to a depth of half an inch, and antiseptics freely applied to the surface. Fomentations with warm water may also be used to favor oozing from the incisions and to encourage the formation of white matter in the original wounds, which must not be allowed to close again at once. A free, creamlike discharge implies a healthy action in the sore, and is the precursor of recovery.

_Phymosis and paraphymosis._--In cases of swelling, as above, the penis may be imprisoned within the sheath (phymosis) or protruded and swollen so that it can not be retracted into it (paraphymosis). In these cases the treatment indicated above, and especially the scarifications, will prove a useful preliminary resort. The use of astringent lotions is always desirable, and in case of the protruded penis the application of an elastic or simple linen bandage, so as to press the blood and accumulated fluid out, will enable the operator to return it.

_Tumors on the spermatic cord._--These are due to rough handling or dragging upon the cord in castration, to strangulation of unduly long cords in the external wound, to adhesion of the end of the cord to the skin, to inflammation of the cord succeeding exposure to cold or wet, or to the presence of infection (_Staphylococcus botriomyces_). These tumors give rise to a stiff, straddling gait, and may be felt as hard masses in the groin connected above with the cord. They may continue to grow slowly for many years until they reach a weight of 15 or 20 pounds, and contract adhesions to all surrounding parts. If disconnected from the skin and inguinal canal they may be removed in the same manner as the testicle, while if larger and firmly adherent to the skin and surrounding parts generally, they must be carefully dissected from the parts, the arteries being tied as they are reached and the cord finally torn through with an ecraseur. When the cord has become swollen and indurated up into the abdomen such removal is impossible, though a partial destruction of the mass may still be attempted by passing white-hot, pointed irons upward toward the inguinal ring in the center of the thickened and indurated cord.

CASTRATION BY THE COVERED OPERATION.

This is only required in case of hernia or protrusion of bowels or omentum into the sac of the scrotum, and consists in the return of the hernia and the application of the caustic clamps over the cord and inner walls of the inguinal canal, so that the walls of the latter become adherent above the clamps, the canal is obliterated, and further protrusion is hindered. For the full description of this and of the operation for hernia for geldings, see remarks on hernia.

CASTRATION OF THE MARE.

Castration is a much more dangerous operation in the mare than in the females of other domesticated quadrupeds and should never be resorted to except in animals that become unmanageable on the recurrence of heat and that will not breed or that are utterly unsuited to breeding. Formerly the operation was extensively practiced in Europe, the incision being made through the flank, and a large proportion of the subjects perished. By operating through the vagina the risk can be largely obviated, as the danger of unhealthy inflammation in the wound is greatly lessened. The animal should be fixed in a trevis, with each foot fixed to a post and a sling placed under the body, or it may be thrown and put under chloroform. The manual operation demands special professional knowledge and skill, but it consists essentially in making an opening through the roof of the vagina just above the neck of the womb, then following with the hand each horn of the womb until the ovary on that side is reached and grasped between the lips of forceps and twisted off. It might be torn off by an ecraseur especially constructed for the purpose. The straining that follows the operation may be checked by ounce doses of laudanum, and any risk of protrusion of the bowels may be obviated by applying the truss advised to prevent eversion of the womb. To further prevent the pressure of the abdominal contents against the vaginal wound the mare should be tied short and high for twenty-four or forty-eight hours, after which I have found it best to remove the truss and allow the privilege of lying down. Another important point is to give bran mashes and other laxative diet only, and in moderate quantity, for a fortnight, and to unload the rectum by copious injections of warm water in case impaction is imminent.

STERILITY.

Sterility may be in the male or in the female. If due to the stallion, then all the mares put to him remain barren; if the fault is in the mare, she alone fails to conceive, while other mares served by the same stallion get in foal.

In the stallion sterility may be due to the following causes: (a) Imperfect development of the testicles, as in cases in which they are retained within the abdomen; (b) inflammation of the testicles, resulting in induration; (c) fatty degeneration of the testicles, in stallions liberally fed on starchy feed and not sufficiently exercised; (d) fatty degeneration of the excretory ducts of the testicles (_vasa deferentia_); (e) inflammation or ulceration of these ducts; (f) inflammation or ulceration of the mucous membrane covering the penis; (g) injuries to the penis from blows (often causing paralysis); (h) warty growths on the end of the penis; (i) tumors of other kinds (largely pigmentary), affecting the testicles or penis; (j) nervous diseases which abolish the sexual appetite or that control the muscles which are essential to the act of coition; (k) azoturia with resulting weakness or paralysis of the muscles of the loins or the front of the thigh (above the stifle); (l) ossification (_anchylosis_) of the joints of the back or loins, which render the animal unable to rear or mount; (m) spavins, ringbones, or other painful affections of the hind limbs, the pain of which in mounting causes the animal to suddenly stop short in the act. In the first three of these only (a, b, and c) is there real sterility in the sense of the nondevelopment or imperfect development of the male vivifying element (spermatozoa). In the other examples the secretion may be imperfect in kind and amount, but as copulation is prevented it can not reach and impregnate the ovum.

In the mare barrenness is equally due to a variety of causes. In a number of breeding studs the proportion of sterile mares has varied from 20 to 40 per cent. It may be due to: (a) Imperfect development of the ovary and nonmaturation of ova; (b) cystic or other tumors of the ovary; (c) fatty degeneration of the ovary in very obese, pampered mares; (d) fatty degeneration of the excretory tubes of the ovaries (Fallopian tubes); (e) catarrh of the womb, with mucopurulent discharge; (f) irritable condition of the womb, with profuse secretion, straining, and ejection of the semen; (g) nervous irritability, leading to the same expulsion of the male element; (h) high condition (plethora), with profuse secretion and excitement; (i) low condition, with imperfect maturation of the ova and lack of sexual desire; (j) poor feeding, overwork, and chronic debilitating diseases, as leading to the condition just named; (k) closure of the neck of the womb, temporarily by spasm or permanently by inflammation and induration; (l) closure of the entrance to the vagina through imperforate hymen, a rare, though not unknown, condition in the mare; (m) acquired indisposition to breed, seen in old, hard-worked mares which are first put to the stallion when aged; (n) change of climate has repeatedly been followed by barrenness; (o) hybridity, which in male and female alike usually entails sterility.

_Treatment._--The treatment of the majority of these conditions will be found dealt with in other parts of this work, so that it is only necessary here to name them as causes. Some, however, must be specially referred to in this place. Stallions with undescended testicles are beyond the reach of medicine, and should be castrated and devoted to other uses. Indurated testicles may sometimes be remedied in the early stages by smearing with a weak iodin ointment daily for a length of time, and at the same time invigorating the system by liberal feeding and judicious work. Fatty degeneration is best met by an albuminoid diet (wheat bran, cottonseed meal, rape cake) and constant, well-regulated work. Saccharine, starchy, and fatty food (potatoes, wheat, corn, etc.) are to be specially avoided. In the mare one diseased and irritable ovary should be removed, to do away with the resulting excitability of the remainder of the generative organs. An irritable womb, with frequent straining and the ejection of a profuse secretion, may sometimes be corrected by a restricted diet and full but well-regulated work. Even fatigue will act beneficially in some such cases, hence the practice of the Arab riding his mare to exhaustion just before service. The perspiration in such case, like the action of a purgative or the abstraction of blood just before service, benefits, by rendering the blood vessels less full, by lessening secretion in the womb and elsewhere, and thus counteracting the tendency to the ejection and loss of semen. If these means are ineffectual, a full dose of camphor (2 drams) or of salicin may at times assist. Low condition and anemia demand just the opposite kind of treatment--rich, nourishing, albuminoid feed, bitter tonics (gentian), sunshine, gentle exercise, liberal grooming, and supporting treatment generally are here in order.

Spasmodic closure of the neck of the womb is common and is easily remedied in the mare by dilatation with the fingers. The hand, smeared with belladonna ointment and with the fingers drawn into the form of a cone, is introduced through the vagina until the projecting, rounded neck of the womb is felt at its anterior end. This is opened by the careful insertion of one finger at a time, until the fingers have been passed through the constricted neck into the open cavity of the womb. The introduction is made with a gentle, rotary motion, and all precipitate violence is avoided, as abrasion, laceration, or other cause of irritation is likely to interfere with the retention of the semen and consequently with impregnation. If the neck of the womb is rigid and unyielding from the induration which follows inflammation--a rare condition in the mare, though common in the cow--more force will be requisite, and it may even be needful to incise the neck to the depth of one-sixth of an inch in four or more opposite directions prior to forcible dilatation. The incision may be made with a probe-pointed knife, and should be done by a professional man if possible. The subsequent dilatation may be best effected by the slow expansion of sponge or seaweed tents inserted into the narrow canal. In such cases it is best to let the wounds of the neck heal before putting to horse. An imperforate hymen may be freely incised in a crucial manner until the passage will admit the human hand. An ordinary knife may be used for this purpose, and after the operation the stallion may be admitted at once or only after the wounds have healed.

PREGNANCY.

INDICATIONS OF PREGNANCY.

As the mere fact of service by the stallion does not insure pregnancy, it is important that the result should be determined to save the mare from unnecessary and dangerous work or medication when actually in foal and to obviate wasteful and needless precautions when she is not.

The cessation and nonrecurrence of the symptoms of heat (horsing) are most significant, though not an infallible, sign of conception. If the sexual excitement speedily subsides and the mare persistently refuses the stallion for a month, she is probably pregnant. In very exceptional cases a mare, though pregnant, will accept a second or third service after weeks or months, and some mares will refuse the horse persistently, though conception has not taken place, and this in spite of warm weather, good condition of the mare, and liberal feeding. The recurrence of heat in the pregnant mare is most liable to take place in hot weather. If heat merely persists an undue length of time after service, or if it reappears shortly after, in warm weather and in a comparatively idle mare, on good feeding, it is less significant, while the persistent absence of heat under such conditions may be usually accepted as proof of conception.

An unwonted gentleness and docility on the part of a previously irritable or vicious mare, and supervening on service, is an excellent indication of pregnancy, the generative instinct which caused the excitement having been satisfied.