Equine infectious anemia (EIA), colloquially known as swamp fever, mountain fever, slow fever, equine malarial fever and Coggins disease, is a viral disease infecting all members of the Equidae including, horses, ponies, mules, and donkeys. (Sellon, 1993; Nakajima and Sugiura, 1994; Burki et al., 1992). Transmission of the virus requires direct blood transfusion, either by biting insects or other mechanical vectors such as contaminated needles. EIA usually is clinically diagnosed as a chronic disease with a high percentage of affected horses demonstrating weight loss, depression, dependent edema, and reduced haematocrit values, platelet counts, and haemoglobin. The majority of horses infected with EIA virus, however, appear to demonstrate none of the clinical abnormalities (Sellon, loc. cit.; Issel and Foil, 1984; Coggins, 1984).