Haemophagocytic syndrome with disseminated intravascular coagulation in a dog

Clinical signs and haematological abnormalities of haemophagocytic syndrome of unknown origin are described for a male, nine-year-old rottweiler referred because of weakness, depression, mild weight loss and relapsing fever. Mucous membranes were pale and the spleen was enlarged. Ultrasonography revealed diffuse irregular structures in the enlarged spleen, and cytological examination of multiple fine needle aspirates of the spleen demonstrated extramedullary haematopoiesis. Haematological examination revealed pancytopenia and disseminated intravascular coagulation. A bone marrow smear contained numerous marrow macrophages with a cytologically benign appearance, containing phagocytosed haematopoietic cells. The dog died one week after referral. The differential diagnosis is discussed.