Dissecting aortic aneurysm in a horse

A case of dissecting aortic aneurysm in a 4-year-old male thoroughbred hors e is reported. The horse had a history of inflammation in the right thigh a nd a fever 2 weeks before sudden death. At necropsy, aortic aneurysms were observed from the aortic valve to the aortic arch, spreading over a distanc e of 40 cm. An irregular rupture of the intima of the ascending aorta was l ocated in the cardiac side of a ramification to the tunica branchiocephalic us communis. An intramural haematoma, apparent on the cut surface and in th e pericardium, had caused cardiac tamponade and sudden death. (C) 1999 W.B. Saunders Company Limited.