Clostridium perfringens cellulitis and immune-mediated hemolytic anemia in a horse.

A 10-year-old Quarter Horse mare was referred for evaluation and treatment of a large pectoral skin slough and hemoglobinuria. The skin slough was secondary to Clostridium perfringens cellulitis and associated gas gangrene. Cold hemagglutinin disease was diagnosed and was suspected to be secondary to C perfringens septicemia. The autoimmune hemolytic anemia, severe intravascular hemolysis, and hemoglobinuria were treated with dexamethasone and hydrocortisone. The infection was treated with 20 X 10(6) units of sodium penicillin, IV, 4 times daily, and the wound was debrided. When the mare relapsed, treatment was changed to 6 g of chloramphenicol sodium succinate, IV, 4 times daily. The mare died on day 11 of hospitalization, despite intensive therapy.