Pericardial haemangiosarcoma in a horse

A primary pericardial haemangiosarcoma with metastasis to the parietal pleura and left adrenal gland is described in a 22-year-old Clydesdale x Percheron gelding. Although haemangiosarcomas have been reported in horses, the pericardium has not hitherto been described as the primary site of origin.