Chronic Intestinal Pseudo-Obstruction Caused by Intestinal Adenocarcinoma in a Mixed-Breed Dog

A 9-year-old, mixed-breed, castrated male dog presented with a one-week history of severe vomiting. Abdominal radiography showed a dilated small intestine loop. Abdominal ultrasonography showed small-intestine distension up to 5 cm in diameter without mechanical obstruction. During exploratory laparotomy, an aperistaltic ileal segment was resected. There was no narrowed cavity in the resected plane. Histopathologic and immunohistochemical findings confirmed visceral myopathy due to intestinal adenocarcinoma in the ileum and revealed partial destruction of the longitudinal and circular muscles with fibrosis. Chronic intestinal pseudo-obstruction caused by adenocarcinoma was diagnosed after considering the above investigative results.