Incarceration of the small intestine through a rent in the gastrosplenic ligament was diagnosed in five horses. Three affected horses were mature males and two were mature females. Persistent moderate to severe abdominal pain, elevated heart rate, congested mucous membranes, serosanguineous peritoneal fluid, and distended small intestine on rectal examination were consistent findings.
Exploratory celiotomy or gross necropsy examination showed the incarcerated intestine to be distal jejunum or ileum. In all horses, the intestine had herniated cranially through the rent in the gastrosplenic ligament. The incarcerated intestine was situated lateral to the stomach and craniolateral to the spleen. Three horses underwent exploratory celiotomy, and the incarcerated small intestine was reduced by gentle traction and then resected. Two of these horses were alive more than 2 years postoperatively without recurrence of signs of abdominal pain, and one was euthanized because of dehiscence of the abdominal incision. Two horses were euthanized without surgical intervention, and necropsy examination revealed a recent rent in the gastrosplenic ligament. This condition should be considered in the differential diagnosis of causes of small intestinal strangulation and obstruction in the horse.