Treatment is unsatisfactory. The preventive treatment consists in not breeding animals that have poorly conformed knees and using the proper judgment in working young horses and when driving or riding horses. Certain cases may be greatly benefited by sectioning the tendons of the external and middle flexors of the metacarpi. To insure a successful outcome in any case that is operated on, a long period of rest is required.
[Illustration: FIG. 33.—Sprung knees.]
[Illustration: FIG. 34.—Splints.]
SPLINTS.—A splint is a bony enlargement situated along the line of articulation between the splint and cannon bones (Fig. 34). This blemish is due to an inflammation of the periosteum. It is a very common blemish and is generally located along the splint bones of the forefeet, especially the internal ones.
Splints are caused by strains and rupture of the ligament that binds the splint bone to the cannon bone. The result is an inflammation of the periosteum. Slipping, or an unbalanced condition of the foot, may cause this injury by distributing the weight unequally on the splint bones. Faulty action and bad shoeing may cause the horse to strike and bruise the region.
Symptoms of lameness are not always present. A high splint involving the articulation between the lower row of carpal, splint and cannon bones may be considered an unsoundness, because of the persistent character of the lameness. The animal may show little or no lameness when walked, but if moved at a trot, especially over a hard roadway, it may show marked lameness. The local inflammation is characterized by a small swelling lying along the splint bone, that feels hot and may pit on pressure. After a time the inflammation disappears and is replaced by a hard, bony enlargement. When this occurs the lameness disappears.
The preventive treatment consists in keeping the feet of young horses in proper balance by frequent trimming and proper shoeing. This attention is very necessary in young colts that are running in pasture. It is very advisable to rest the animal during the period of inflammation. Cold bandages should be applied. As soon as the inflammation has subsided mild counterirritants and absorbents may be used. In. case the lameness persists, more severe counterirritation is indicated.
INFLAMMATION OF THE FLEXOR TENDONS OF THE DIGIT.—The large tendons posterior to the foot and the suspensory ligament that separates them from the cannon bone frequently become inflamed. Sometimes complete rupture of one or more of these structures occurs. The lighter breeds of horses are the most frequent sufferers. Because of the greater strain thrown on the tendons of the forefeet, inflammation of these tendons is far more common than it is in the hindfoot. Diseased conditions of the hind tendons are usually due to other causes than strain.
The following predisposing and accidental causes should be considered: Weak flexor tendons and heavy bodies predispose animals to inflammation of the tendons and suspensory ligament; quality, not size, is the factor to consider when judging the strength of a tendon; long, slender pasterns increase the strain on these structures, and this mechanical strain is further increased by low heels and long toes; the character of the work and the condition of the road that the animal travels over are important factors to consider; trotting and running horses more often suffer from injuries to tendons and ligaments than draft horses; travelling at a high rate of speed over an uneven road, slipping and catching the foot in a rut or car track, are common causes; bruises and wounds may result in the tendons becoming inflamed; inflammation of the tendinous sheaths and the tendons as well sometimes occurs in influenza.
Lameness is a prominent symptom. The pastern is held in a more upright position than normal. When the animal is standing, the foot is rested on the toe, and it may take advantage of any uneven place on which to rest the heel. In severe strains the local symptoms are quite prominent. The tendons may be hot and swollen. Pressure may cause the animal pain. In chronic tendinitis the tendon may be thickened and rough or knotty. Pain is not a prominent symptom in this class of cases. Shortening of the inflamed tendon may occur, causing the animal to knuckle over. Rupture of one or more of the tendons and the suspensory ligament can be recognized by the abnormal extension of the pastern. If the ruptured tendon heals, it always results in a thickening at the point of the rupture that gives the tendons a bowed appearance. This is termed bowed-tendon.