Mesodiverticular bands as a cause of small intestinal strangulation and volvulus in the horse.

Volvulus of the jejunum and ileum in three horses was associated with intestinal strangulation in a mesenteric rent. The rent was in the jejunal mesentery at its point of attachment with an anomaly that was classified as a mesodiverticular band. The band also was attached to the dorsolateral surface of the jejunum, thus forming one side of a triangular hernial sac that was completed on the other side by the adjacent jejunal mesentery. Incarceration of a loop of small intestine in the hernial sac preceded rupture of the jejunal mesentery and subsequent intestinal strangulation. Surgical correction was successful in two horses and involved resection of the gangrenous intestine, then jejunocecal anastomosis. The third horse was euthanatized when intestinal rupture and peritonitis were found on exploratory laparotomy. Two mesodiverticular bands attached to the distal jejunum were incidental necropsy findings in a fourth horse.