Acute Abdominal Aortic Rupture in a Mare on Transit

A four year old thoroughbred mare in the company of two other horses collapsed and died while on transit from Nairobi to Eldoret (distance of about 311 Km), Kenya. The animal had successfully participated in a horse racing event and was on its way home. Reports indicated that the mare had been healthy for the last one year and had no unusual clinical finding before, during or after racing. The blood smear at ante-mortem was negative for Anthrax bacilli. Necropsy revealed a pale carcass with lots of blood clots in the abdominal cavity, heart chambers devoid of blood and a 10 cm long ventral longitudinal tear of the abdominal aorta. The aortic tear was surrounded with blood clots. The aortic wall was thinner with increased luminal diameter at the level of rupture compared with the unaffected part; suggestive of a pre-existing aneurysm. It is concluded that the patient may have died of hypovolemic shock resulting from severe hemorrhage.