Equine infectious anaemia (EIA) is a worldwide distributed disease in Equidae, caused by a retrovirus, with acute lethal to chronic recurrent forms. Characteristic signs are recurrent fever, anaemia, thrombocytopenia, oedema and considerable weight loss. Transmission takes place via infected blood, blood-sucking insects, iatrogenic through infected injection equipment, but also intrauterine.
Once infected horses remain infectious and seropositive throughout their lives. All horses older than 6 months that are seropositive are thus considered carriers; younger horses can be seropositive through maternal antibodies. Normally, the incubation period is 1 – 3 weeks, but may also last up to 3 months.
In Germany, there is an obligation to inform the authorities upon suspicion, as EIA is an epizootic disease!