Equine infectious anemia, commonly known as swamp fever, is a viral disease that attacks the horse’s immune system. There are no cure and no vaccine for this viral infection, which is caused by a retrovirus closely related to the HIV virus in humans–the cause of AIDS. It’s recommended by the American Association of Equine Practitioners that horses testing positive for EIA antibodies be euthanized humanely. Most horses exposed to the equine lentivirus, the virus that causes EIA, progress without outward symptoms of the disease.

EIA was first identified in France in 1843, and initially was diagnosed in the United States in 1888. The virus is found worldwide, and steps have been taken by authorities around the globe to control the spread of this dreaded disease. According to Chuck Issel, DVM, PhD, of the Gluck Equine Research Center in Lexington, Ky., when EIA was first able to be diagnosed, it was discovered that some farms and ranches in the United States had a 100% infection rate, while other farms and ranches had a zero percent infection rate. Even today, Issel said, “There are populations of horses found each year with an EIA infection rate approaching 100%.”

In 1970 Leroy Coggins, DVM, developed the first reliable test to diagnose EIA. In an effort to control the spread of EIA, and initially in hopes of totally wiping out the disease in the United States, the USDA, along with state regulatory bodies, recommended that all horses which come in close proximity to other horses be tested for EIA. Blood samples taken from the horse must be sent to a state-approved laboratory for a Coggins test to be performed. The test now is mandatory to register your horse for a show or to cross state boundaries in all 50 states. Some states even go so far as to require a negative Coggins test to sell your horse.

“Testing for EIA virus antibodies should be conducted on any horse which the past history is not known,” said Issel