SPAVIN.
—This disease, known in common language as bone spavin, is an enlargement of the hock joint similar to a ringbone about the coronary joint. It may affect the hock joint in such a way as to cement the small joints together, not causing lameness, and apparently no blemish, but the free movement of the limb is impaired. Any condition which favors sprains, such as fast driving over hard or uneven roads, unequal paring of the hoof, thus causing the weight to be unequally distributed in the joints, and severe labor in early life, or blows, bruises, or any injuries to tendons, ligaments, or joints may cause spavin. In addition to these causes may be mentioned sprains caused by jumping, galloping, or trotting animals faster than they are accustomed to; also straining by starting a heavy load, slipping on an icy surface or sliding on a bad pavement.
If the patient is examined before any bony growth has developed, inflammation will be detected on the inside of the hock joint at the junction of the cannon bone and the joint. While in the stable the horse prefers to rest the diseased leg by setting the heel on the toe of the opposite foot with the hock joint flexed. In traveling the patient is very lame when first taken out of the barn, but after traveling for a short distance goes sound. The diseased leg is not lifted clear from the ground, but nicks the toe in the middle of the stride, which is very noticeable on a pavement. A strained horse becomes very lame after being allowed to stand for even a very short time, then moved again.
Preventive treatment consists in keeping horses’ feet trimmed properly, not overworking colts while young, careful driving on hard or uneven roads, and avoiding all injuries that are liable to strain tendons, ligaments or joints of the limbs. Even after a spavin has developed it may be cured by proper treatment of the feet, and applying a fly blister. The fly blister is prepared by mixing thoroughly 4 tablespoonfuls of pulverized cantharides, 4 tablespoonfuls of biniodide of mercury and 8 ounces of lard. The hair is clipped over the spavin and the blister applied with considerable rubbing. The horse’s head should be tied so as to avoid his biting the part blistered. A second application of the blister is to be used about a month after the first. If blistering fails to cure the spavin, point-firing may be resorted to. It is necessary to “fire” rather deeply to secure good results, care being taken not to fire into a joint. After firing, a fly blister should be rubbed into the holes where the hot iron has been used.