ABSTRACT
The distal end of the swelling has a notched appearance. The horse has a slightly broken back hoof-pastern axis and low heels. ii. Annular ligament syndrome is the most obvious possibility. Superficial or deep digital flexor tendon injuries, or previous penetrating wounds into the sheath, may be contributing factors. But in view of the poor foot conformation, a foot problem should also be considered as the cause of the lameness, since these digital sheath swellings are not always painful. iii. Intrasynovial analgesia of the digital sheath will not always abolish the lameness, presumably because of adhesions or the mechanical influence of the constricted annular ligament. Analgesia of the palmar nerves proximal to the fetlock is usually effective. Ultrasonography is important for evaluation of the annular ligament and the flexor tendons, and may indicate the presence of adhesions. Regional analgesia of the foot should be performed to ensure that foot pain is not involved. iv. Acute cases should be treated with rest, possibly combined with both topical and systemic anti-inflammatory drug therapy. If this fails, an annular ligament desmotomy is indicated.
