Type III atresia coli with underdeveloped colon and hydroperitoneum in a newborn foal

A 48-hour-old mixed breed pony colt was referred to the hospital because of abdominal discomfort, weak suckling reflex and prostration. During clinical investigation, supportive and symptomatic treatments were necessary, and an abdominal radiography was performed revealing a large intestine filled with feces and large amounts of gas, in addition to free fluid in the cavity. After 3 days of treatment, the foal had not yet defecated, thus exploratory abdominal surgery was indicated, but the owners declined. Therefore, the foal was humanly euthanized. Post-mortem examination revealed complete absence of the pelvic flexure. Subsequent portions of the dorsal, transverse and small colons were intensely reduced. In addition, at the abdominal cavity there was 850 ml of yellowish translucent liquid. These findings are compatible with hydroperitoneum and type III atresia coli at the pelvic flexure, associated with underdevelopment of the dorsal, transverse and small colons.