POLYCYSTIC HEPATIC-DISEASE, THORACIC GRANULAR-CELL TUMOR AND SECONDARY HYPERTROPHIC OSTEOPATHY IN A HORSE

A 13-year-old American Saddlebred mare was presented with a 4-day hist ory of anorexia. Physical examination revealed increased inspiratory e ffort and bony enlargement of the distal limbs. Radiographs indicated a thoracic mass and periosteal proliferations on the distal limbs cons istent with hypertrophic osteopathy. Gastric endoscopy revealed distal esophageal and gastric ulceration, and functional pyloric stenosis. A bdominal ultrasonographic examination revealed multiple large, cystic structures associated with the liver. A percutaneous biopsy indicated the thoracic mass to be a granular cell tumor. At necropsy, a large ma ss consisting of intercommunicating cystic structures was present conf luent with the right caudal edge of the liver. Histologically these he patic lesions were consistent with cystic hepatic disease, which has n ot previously been reported in the horse.