Part 71

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

CAPPED ELBOW.

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

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

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

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

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

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

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

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

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

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

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

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

CAPPED KNEE.

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

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

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

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

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

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

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

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

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

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

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

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

CAPPED HOCK.