Abstract
A dog with severe heart failure of patent ductus arteriosus showed regenerative anemia, thrombocytopenia, and splenomegaly with masses in the spleen, and also swellen lymph nodes in the abdominal cavity. After medication had alleviated the heart failure, splenectomy was performed, and the general condition improved temporarily, but on day nine after surgery the dog died of developing anemia, thrombocytopenia, hypoalbuminemia, hepatic insufficiency, and renal failure. Histopathological diagnosis was hemophagocytic histiocytic sarcoma. The cytopenia in this case was thought to have been caused by microangiopathic hemolytic anemia in the tumor tissues and/or hemophagocytosis by tumor cells; the latter was suspected to be a major cause, considering the postoperative course of the disease.
