The area of riding horses that is under saddle, or the shoulder area of those driven in harness, is frequently the site of injuries to the skin and deeper soft and bony tissues. Clinical signs vary according to the depth of injury and the complications caused by secondary infection. Emaciated horses are at increased risk. Sores affecting only the skin are characterized by inflammatory changes that range from erythematous to papular, vesicular, pustular, and finally necrotic. Frequently, the condition starts as an acute inflammation of the hair follicles and progresses to a purulent folliculitis. Affected areas show hair loss and are swollen, warm, and painful. The serous or purulent exudate dries and forms crusts. Advanced lesions are termed “galls.” When the skin and underlying tissues are more severely damaged, abscesses may develop. These are characterized as warm, fluctuating, painful swellings from which purulent and serosanguineous fluid can be aspirated. Severe damage to the skin and subcutis or deeper tissues results in dry or moist necrosis. Chronic saddle sores are characterized by a deep folliculitis/furunculosis (boils) with fibrosis or a localized indurative and proliferative dermatitis. Lesions are usually caused by poorly fitting tack.
Identification and elimination of the offending portion of tack is more important than any other treatment. Excoriations and inflammation of the skin of the saddle and harness regions are treated as any other dermatosis. Absolute rest of the affected parts is necessary. During the early or acute stages, astringent packs (Burow solution) are indicated. Chronic lesions and those superficially infected may be treated by warm applications and topical or systemic antibiotics. Hematomas should be aspirated or incised. Necrotic tissue should be removed surgically. In severe folliculitis and furunculosis, antibiotics, ideally chosen on the basis of culture and sensitivity, are always indicated. Scars and/or leukotrichia (white hairs) are common sequelae of healed areas. Recurrence of hematomas, seromas, and/or sloughing skin upon initial saddlings of a young Quarter horse or Paint horse should elicit suspicion of the genetic disease hereditary equine dermal asthenia. A simple DNA test, performed on the hair bulbs of the tail, will confirm this diagnosis.
Last full review/revision May 2013 by Stephen D. White, DVM, DACVD