Ultrasonographic identification of mesenteric lipomatosis in a Shetland mare with recurrent colic episodes

An obese 17-year-old Shetland pony mare with a history of recurrent colic episodes was presented for investigation of colic signs of a few hours' duration associated with marked tachycardia. Transabdominal ultrasonography identified a large amount of multilobulated tissue that was hypoechoic to the adjacent retroperitoneal fat within the caudal and ventral abdomen; this could be seen extending dorsally into the mid-abdomen between intestinal structures. At exploratory laparotomy, a lipoma at the mesenteric attachment of the mid-jejunum (considered likely to have caused intermittent extraluminal compression) as well as excessively thick layers of fat in the mesentery of both small and large intestine (compatible with lipomatosis) were identified. The lipoma was removed. Post-operative recovery was uneventful. A strict diet was enforced, resulting in marked weight loss over the 12-week post-surgery period. Follow-up abdominal ultrasound examination identified a reduction in the thickness of the retroperitoneal fat layer and the abnormal multilobulated tissue. This is the first case report detailing the ultrasonographic findings in a case of extensive mesenteric lipomatosis in a pony and describing the ultrasonographic improvement following a weight loss programme.