Collapse following gastrointestinal bleeding secondary to a congenital duodenal diverticulum in two littermate boxer pups

Two littermates, a young male and female boxer, were admitted to the Utrecht University's Department of Clinical Sciences of Companion Animals within a three month period. Both dogs suffered from anaemia caused by chronic intestinal blood loss, vomiting and weight loss. In both cases, there was no response to conservative medical management. Eventually, the dogs suffered significant gastrointestinal haemorrhage that resulted in collapse. Gastroduodenoscopy and exploratory surgery showed a duodenal diverticulum in both dogs. This is the first report that describes this congenital anomaly in two siblings.