Haemoabdomen is an important differential diagnosis of canine and feline abdominal trauma. The diagnosis is made by aspiration of abdominal blood by abdominocentesis. The spleen and liver are the most likely sources of traumatic bleeding. Patients are stabilized with appropriate fluid therapy, oxygen supplementation and analgesia. With ongoing haemorrhage, the serial measurement of abdominal and venous haematocrit can be helpful in the decision between surgical and medical therapy. Most patients with traumatic haemoabdomen can be treated medically. Surgical therapy should be reserved for patients that cannot be stabilized despite medical intervention. The surgical approach should be thoroughly planned in order to minimize further abdominal blood loss and blood transfusions should be readily available.