Auto-immune haemolytic anaemia in a horse

A case of auto-immune haemolytic anaemia (AHA) in a 7-year-old, pony gelding is described. Diagnosis was based on a strong, positive reaction to the direct Coombs antiglobulin test and the presence of erythrophagocytosis and spherocytosis in peripheral blood smears. The condition was complicated by an infected haematoma, posterior paresis and urinary incontinence. The triggering mechanism behind the antibody response against the red cells is unknown.