Horse Equine Infectious Anemia: Testing and Welfare

Equine Infectious Anemia (EIA) is a viral blood disease with no treatment that causes devastating welfare consequences and requires robust testing and management programs.

Key Facts

EIA is caused by a lentivirus transmitted by biting insects and blood-contaminated equipment
Coggins test (agar gel immunodiffusion) or ELISA testing is required for horse movement in many countries
Acutely infected horses experience fever, anemia, weakness, and edema in severe cases
Some infected horses become inapparent carriers who appear healthy but can transmit virus to other horses
There is no vaccine and no treatment — infected horses must be quarantined or euthanized in most jurisdictions
Strict needle and equipment hygiene between horses eliminates iatrogenic transmission risk

Welfare Considerations

EIA welfare impacts occur at multiple levels. Acutely ill horses suffer significantly from fever, anemia, and systemic disease. Horses who test positive face euthanasia or lifetime quarantine — a devastating outcome for owners and a profound welfare event for animals who have had no choice in their exposure. The mandatory test-and-remove systems that control EIA protect population welfare at the cost of individual animal welfare. Prevention through strict equipment hygiene is therefore not only a disease control priority but an animal welfare one, as preventing infection prevents both the disease and its consequences.

What You Can Do

Maintain current Coggins or EIA test certificates for all horses you move between properties or to competitions
Never share needles, syringes, or blood-contaminated equipment between horses
Check that any veterinarian drawing blood uses new needles and appropriate hygiene between horses
Report any horse with unexplained fever, weakness, and edema to your vet, noting the possibility of EIA
Support surveillance testing programs that identify inapparent carriers before they transmit infection
Understand that test-and-remove policies, while devastating for individual horses, protect population welfare