Part 70

A variety of causes may produce inflammation of the foot between the claws or toes. It may be on account of overgrowth of the claws and inward pressure, as in ingrowing nail of man, or it may be caused by the irritation of stable filth by impaction and hardening of soil between the claws, or by other foreign substances becoming wedged in, causing inflammation and softening or ulceration of the skin in the interdigital space. Under some conditions several cattle in the same herd become affected, which has led some to think that the disease may be contagious. Occurrences have been reported in which foot rot of cattle has appeared within a short time among a large proportion of the cattle in a farming district. This disease is most frequently seen in the hind feet, though all four feet may become affected.

Symptoms.--The animal is observed to limp. On examination of the foot we discover heat and swelling above the hoof and of the soft parts between the claws which frequently spreads the claws apart to a considerable extent, or the inflammation may have advanced to softening and sloughing of the interdigital membrane. If the disease is neglected at this stage, deep abscesses may form and the pus burrow under the horny wall, or the joint within the hoof may become inflamed and the articular attachments destroyed, in which case the treatment will be difficult and recovery will be very tedious.

Treatment.--In the earlier stages of the disease, before pus burrows beneath the horn, a thorough cleansing and an application of a carbolic-acid solution--1 ounce to a pint of water--clean stabling, and laxative food will usually remedy the evil. Compound solution of cresol is an excellent remedy at this stage. It should be applied, in its pure or undiluted state, to the suppurating and putrefying tissue between the claws. It is best applied by means of a cotton swab on a thin stick. Care must be taken to keep it from contact with the skin about the coronary band or heels. If deep sloughing has taken place the carbolic solution should be used, and a wad of oakum or cotton smeared with pine tar should be secured firmly in the cleft. This can be done by taking a strip of strong cloth, 2 inches wide, passing the middle between the claws, then tying the ends after winding them in opposite directions above the hoof. Sometimes warm poulticing with flaxseed meal or bran is necessary to relieve excessive fever and pain. If the pus burrows under the horn, its channel must be followed by paring away the horn until the bottom is reached. The aftertreatment is the same as that already recommended. If the joint becomes diseased an amputation of that toe is the quickest and surest method to relieve the suffering of the animal, and offers the best chance for an early recovery.

ULCERATION OF THE HEEL.

Occasionally we find ulcers at the junction of the hair with the hoof at the heel, which present an elevated, raw, or ragged surface, and cause considerable lameness. This is generally caused by a bruise of the fibrous cushion of the back part of the foot. Subsequent sloughing or necrosis may occur, or pus may form deep within the wall and gain an exit at the margin of the heel. Sometimes, from no visible cause, large pieces of skin slough from the heel and pastern. This condition is caused by an infection with certain microorganisms (streptococci, necrosis bacilli) and may be contagious.

Treatment.--If there is a deep opening, inject carbolic solution once a day until it closes. If the ulcer is only superficial, wash with carbolic solution and apply a mixture of equal parts of blue vitriol and alum in dry powder.

FISSURE OF THE WALL (SPLIT HOOF).

This is rarely seen among cattle. It may occur in weak walls, in heavily bodied cattle, caused by stepping on an uneven surface, especially when the point of the toe is grown out long. One may find the point of the toe broken and the wall split almost up to the hair.

Treatment.--The divided sections may be brought into approximation and held in place by drilling a small hole from one side into and through the other, commencing half an inch back of the fissure on each side; then drive a light horseshoe nail through the hole and clinch it. Pare the injured claw as short as it will bear.

INTERDIGITAL FIBROMA.

Hard, nodular, fibrous tumors sometimes grow in the cleft of the foot, and cause inconvenience, lameness, absorption, or ulceration of the contiguous parts.

Treatment.--They should be dissected out and the wound dressed with carbolic-acid lotion and pine tar once a day until healing is completed.

DEFORMITIES.

Deformities in the feet of cattle usually consist in overgrowth of horn, generally from want of wear in animals which are stabled. The hoof may turn inward, outward, or upward, and may give rise to lameness, inability to walk, foul foot, etc. Bulls which are continually stabled and dairy cows very frequently have misshapen feet from want of an occasional trimming, and this deformity may eventually lead to permanent injury.

Treatment.--Cut the superabundant growth of horn down with saw, knife, or rasp, until the foot assumes its natural form.

PRICKS AND WOUNDS.

If an animal suffers with a penetrating wound from prick of fork or nail, the orifice of the wound should be enlarged to permit a free discharge of pus; then the foot should be soaked in a cresol compound solution (3 per cent) in a tub, or a flaxseed poultice applied, changing it three times a day until the fever has abated. The foot should be kept bandaged and dressed with pine tar and oakum; the animal must also be kept on a clean floor until the wound is closed and all or nearly all lameness has disappeared.

If an animal is cut in the foot with barbed wire, piece of glass, or any other substance, the wound, after proper cleansing, should be dressed with carbolic-acid solution, 1 ounce of the acid to 20 of water. If any uneven edges of horn, skin, or lacerated flesh project, trim them off, and in all cases when it can be done a tarred bandage should be applied. This will serve to sustain the cut surfaces in their place, exclude dirt, and protect against flies, maggots, etc.

When the wound has extended into a joint, surgical treatment, which will require the services of an educated veterinarian, may be necessary.

Occasionally an animal gets caught by the foot in a crevice and sustains severe bruising, wrenching, or fracture of some part of the foot. In such cases cold-water packs to the injured member are of service until the fever and swelling disappear. Afterwards the animal should rest until the usefulness of the foot is restored. Sometimes such an accident, causing fracture, renders necessary plaster bandages or amputation.

DISEASES OF THE EYE AND ITS APPENDAGES.

By M. R. TRUMBOWER, D. V. S.

DESCRIPTION.

For the sake of gaining a clear comprehension of the diseases of the eye it becomes necessary to review the anatomy of this important organ. The essential organ of vision, or globe of the eye, will be first described, then its receptacle or orbital cavity, the muscles that move it, the protective membranes, or eyelids, the membrana nictitans, or accessory eyelids, and, lastly, the lacrimal apparatus.

The globe or ball of the eye is almost spherical in form. On closer inspection, however, it appears to be made up of two combined portions from spheres of different sizes. The posterior portion, forming about five-sixths of the ball, is a sphere of comparatively large size with a small segment cut off it in front, and at this point there is applied to it the anterior portion, which, being a segment of a smaller sphere, projects at the front of the ball with a greater convexity than the posterior portion.

The eyeball consists of concentrically arranged coats and of refracting media inclosed in them. The coats are three in number, namely, (1) an external protective tunic made up of the sclerotic and cornea; (2) a middle vascular and pigmentary tunic, the choroid; (3) an internal nervous layer, the retina. The sclerotic is the white, opaque part of the outer tunic, of which it forms about the posterior five-sixths, being coextensive with the larger sphere already mentioned. The cornea forms the remaining one-sixth of the outer tunic, being coextensive with the segment of the smaller sphere. It is distinguished from the sclerotic by being colorless and transparent. The choroid coat will be recognized as the black layer lying subjacent to the sclerotic. It does not line the cornea, but terminates behind the line of junction of that coat with the sclerotic by a thickened edge--the ciliary processes. At the line of junction of the sclerotic and cornea the iris passes across the interior of the eye. This (which may be viewed as a dependency of the choroid) is a muscular curtain perforated by an aperture termed the pupil. The retina will be recognized as a delicate, glassy layer, lining the greater part of the choroid.

The refracting media of the eye are three in number, namely (1) the aqueous humor, a watery fluid inclosed in a chamber behind the cornea; (2) the crystalline lens and its capsule, a transparent, soft solid of a biconvex form, and placed behind the iris; (3) the vitreous humor, a transparent material with a consistence like thin jelly, and occupying as much of the interior of the eye as is subjacent to the choroid.

The sclerotic is a strong, opaque, fibrous membrane, which, in a great measure, maintains the form of the eyeball and protects the more delicate structures within it. Its interior portion, which is covered by the ocular conjunctiva, is commonly known as the "white of the eye." In form it is bell-shaped, and the optic nerve pierces it behind like a handle, the perforation being a little to its inner side. In front, the rim of the bell becomes continuous with the cornea. The outer surface of the membrane receives the insertion of the muscles of the eyeball. The coat is thickest over the posterior part of the eyeball, and is thinnest a little behind its junction with the cornea.