Granulomatous enteritis and cutaneous arteritis in a horse

A 5-year-old Quarter Horse mare was examined because of weight loss of 2 months' duration. The horse was anemic and in poor body condition, and had several areas of cutaneous ulceration, including areas on the muzzle and distal portion of the limbs. Histologic examination of a rectal mucosa biopsy specimen revealed a lymphoplasmacytic infiltrate in the lamina propria mucosa. Results of a glucose absorption test were suggestive of malabsorption. Histologic examination of a biopsy specimen from the cutaneous lesions revealed pronounced arteritis, and weak, patchy immunofluorescent staining for immunoglobulins at the basement membrane. The horse was treated with prednisone, but did not improve, so the horse was humanely destroyed. Necropsy revealed granulomatous enteritis. This case identified an unusual combination of clinical problems and suggests further evidence for similarities between equine granulomatous enteritis and regional enteritis in human beings.