Immune-mediated hemolytic anemia (IMHA) in cats part 1: A review

Abstract

In contrast to dogs, immune-mediated hemolytic anemia is rarely seen in cats and occurs most often secondary to an underlying infectious, neoplastic or inflammatory process. Clinical symptoms are often vague and are caused by severe anemia and the effect of hypoxia on organ systems. Laboratory abnormalities in cats with IMHA are comparable to those seen in dogs, with the exception of spherocytes, which are difficult to identify in cats. The diagnosis is based on hemolytic anemia in combination with a positive 'true' autoagglutination and/or a positive Coombs test. A search for underlying causes should always be performed and, because infections with hemotrophic mycoplasma species are the most important underlying cause for IMHA in cats, a polymerase chain reaction test to detect these bacteria should be carried out. Treatment consists of immunosuppressive drugs, providing oxygen-carrying solutions, treating underlying causes and supportive care. In cats, IMHA carries a better prognosis than in dogs, although relapses are seen in equal frequency.