Each year we are told we need to have a negative Coggins to travel anywhere. But what really are we testing for? A Coggins test, in medical terms, is an EIA test – which stands for Equine Infectious Anemia. It is a disease that is transmitted primarily through insects (particularly horse flies and deer flies) and can infect horses, ponies, donkeys and mules.
There is no vaccine for this virus. A horse diagnosed positive for EIA dies, is euthanized, or gets placed under extremely strict quarantine conditions (at least 200 yards away from other animals) for the rest of his life.
One of the main symptoms for the disease is fever, which makes it hard to diagnosis or differentiate from other fever-producing diseases like influenza and encephalitis. And although most infected horses show no symptoms, they remain contagious for life, endangering the health of other horses.
Transmission of EIA occurs mainly through the transfer of contaminated blood from one animal to another. Insects such as horse flies, stable flies, and deer flies aid in the disease spread. EIA can also be transmitted through the semen of an infected stallion