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

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

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

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

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

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

SUNDRY ADDITIONAL AFFECTIONS OF THE EXTREMITIES.

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

Severe inflammation, with suppuration, may follow, which, filling up the cavity, the walls will become thickened and hard, resulting in the formation of a tumor.

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

They will be considered in their peculiar aspect.

CAPPED ELBOW.

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

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

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

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

In other cases an entirely different process takes place. The walls of the cavity, cyst, or abscess become ulcerated and thickened, the granulations of the sac become fibrous in their structure and fill up the cavity, and it a.s.sumes the character of a hard tumor on the back of the elbow, sometimes partly and sometimes entirely covered by the skin.

It is fibrous in its nature, painless to the touch, well defined in its contour, and may vary in size from that of a small apple to that of a child's head.

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

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

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

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

But cases occur in which all the treatment that has been described fails to effect a full recovery, and instead a fibrous tumor begins to develop. A change of treatment is, of course, then in order. The inflammation being chronic will necessitate stimulating treatment of the part in order to increase the process of absorption. We must again draw upon the resources of experience in the form of blisters, the fomentations, the iodin, and the mercurial ointments, as heretofore mentioned. Good results may always be insured from their judicious and timely administration. In applying the powerful mineral inunctions much patience and wisdom are required. It should be done by carefully and perseveringly rubbing in small quant.i.ties daily; it should be done softly and gently, not with force, nor with the expectation of producing an astonishing effect by heavy dosing and main strength in a few hours; it should be after the manner of a siege rather than that of a charge.

The object is to induce the drugs to permeate the affected part until the entire ma.s.s is penetrated. Of course cases will be encountered which resist all forms of medical treatment. The tumor remains as a fixed fact; it continues to grow; it is large and pendulous at the elbow; its weight is estimated in pounds; it is not an eyesore merely, but an uncomfortable, burdensome ma.s.s, excoriating all the surrounding parts and being itself excoriated in turn; mild treatment has failed and is no longer to be relied on.

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

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

CAPPED KNEE.

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

_Cause._--The capped knee presents itself under various conditions. It is sometimes the result of a bruise or contusion, often repeated, inflicted upon himself by a horse addicted to the habit of pawing while in the stable and striking the front of the stall with his knees.

Another cla.s.s of patients is formed of those weak-kneed animals which are subject to falling and bruising the front of the joint against the ground, the results not being always of the same character.

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

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

Instead of being filled with blood the swelling may be full of serum, as often occurs when violence, though perhaps slight, has been frequently repeated. In that case the swelling is generally well defined, soft, and painless, with more or less fluctuation, and it may even become pendulous. In other cases the swelling may be of an acute, inflammatory nature, with heat and pain, accompanied with stiffness of the joint.

This leads to the formation of an abscess. Whatever the nature of these swellings may be, either full of blood, serum, or pus, some blemish usually remains after treatment.

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

_Treatment._--Usually the first symptom of trouble is the edematous swelling on the front of the "knee." The prevention of the inflammation and consequently of the abscess, is the prime object in view, and it may be realized by the use of warm-water fomentations or compresses applied over the swelling, which may be used either in a simple form or combined with astringents, such as Goulard's extract, alum, or sulphate of zinc.

The application of warm poultices of oil meal or ground flaxseed, enveloping the whole joint and kept in place by bandages, is often followed by absorption of the swelling, or, if the abscess is in process of formation, by the active excretion of pus. If an abscess forms in spite of these precautions it may be treated surgically in several ways.

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

As we have remarked, the cavity after being emptied may rapidly close and leave in a short time but slight traces of its previous existence.

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

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

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

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

CAPPED HOCK.

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

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

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

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

and, worse than all, one that kicks when fed.

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

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

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

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