This condition may be congenital or acquired, and the cause is unknown. Affected foals have characteristic swellings over the tendon sheath at the dorsolateral aspect of the carpus. Temporary splint application to prevent knuckling over is the most effective treatment, and surgery is not required. Presumably, the tendon ends fibrose or scar down, because functionally these foals become normal. These deformities are often severe in extent, and often involve one limb only.
Manual correction is often impossible.
Careful evaluation of these cases should be undertaken to determine whether surgical correction is even feasible. Many cases have sufficient contracture of the carpal joint capsule and ligaments to prevent correction, even after transection of all carpal flexor tendons. For less severe forms, temporary splinting is effective. Congenital Flexural Deformities of the Foot and Fetlock Affected animals either stand on the toe, or knuckle forward at the level of the fetlock. Careful palpation of the flexor tendons should be completed in both the weightbearing and non-weightbearing positions, to determine which of the flexor tendons is most involved.