Parietal hernia of the small intestine into the epiploic foramen of a horse.

A 12-year old 573-kg (1,261-lb) Quarter Horse gelding was referred with colic of 12 hours' duration and with poor response to medical treatment. On the basis of physical and laboratory findings, a pelvic flexure impaction was suspected. The horse was treated medically. Because signs of mild abdominal pain persisted and the heart rate had increased, an exploratory celiotomy was performed 30 hours after signs of colic were first noticed. At surgery, the ileum was found partially entrapped within the epiploic foramen, in a left-to-right direction, to form a parietal hernia. The entrapped intestinal segment was reduced but not resected, and the horse recovered fully. In retrospect, the delay before surgery in this horse was tolerated because this was a parietal hernia and, therefore, did not cause complete ileal obstruction. This horse had an unusual form of small-intestinal strangulation in the epiploic foramen that might not cause sufficient obstruction initially to allow early detection.