Equine infectious anemia (low blood cell count, low hemoglobin) is caused by a virus that is primarily transmitted by biting flies (horse and deer flies) or reused needles, but may also be spread by contaminated instruments (including dental equipment), blood transfusions or the transfer from a mare to foal in utero.

EIA is endemic in the United States, but much more common in the South. Although some infected horses do not show any signs of the disease others develop a fever, weakness, or swelling of the lower limbs or abdomen. It has a 30% mortality rate in seriously infected horses. EIA may cause abortion in pregnant mares.

DIAGNOSIS is with the well known Coggins test.

TREATMENT: There is no cure and no vaccine. Euthanasia or permanent quarantine are currently the only accepted approaches.

EIA is a reportable disease, meaning that if a horse has or is suspected of having this disease, vets are required to report it to agricultural authorities (usually the State Veterinarian). These authorities may investigate the case as part of a larger effort to monitor equine health and coordinate with other states and the USDA APHIS in preventing the spread of illness or disease on a national and international level.