A 6-year-old female grey seal (Halichoerus grypus) at the Indianapolis Zoo was presented with acute lethargy and tremors. Five weeks prior to presentation, this animal had a right rear limb amputation at the level of the stifle due to chronic self-mutilation of the rear flippers. Four weeks after surgery, the animal developed elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyltransferase (GGT), and anemia. Initial abdominal ultrasound showed a small amount of hypoechoic fluid near the right kidney. However, one week later, radiographs showed complete loss of abdominal serosal detail, with marked free fluid in the abdomen confirmed on ultrasound. Fluid aspirated from the abdomen was determined to be hemorrhagic effusion with a higher hematocrit than systemic blood. Since splenic fracture, hepatic fracture, or avulsed vasculature in the abdomen were suspected, the animal was kept in dry isolation to minimize movement or disruption of any clots. The animal was maintained on oral and subcutaneous fluids, hepatoprotectants, gastroprotectants, antibiotics, and antifungals. Five days later, recheck ultrasound showed markedly decreased abdominal fluid, although the liver edges appeared be rounded. In the subsequent days, the animal’s attitude and appetite markedly improved, and serial blood work showed increasing hematocrits and normalizing liver enzyme levels. The animal was released back into the exhibit three weeks after initial evaluation. This report describes the clinical course and conservative management of hemoabdomen in a grey seal, with a discussion of possible causes of hemoabdomen in this patient.