Equine infectious anemia (EIA), commonly called "swamp fever" is a viral disease that destroys a horses red blood cells, causing anemia. Once infected, horses remain infected for life, often without showing any signs of the disease. 

    The EIA virus is transmitted by infected blood transferred by biting insects, nonsterile needles, and contaminated equipment. The virus can pass through the placenta and or the colostrum to infect foals. The disease occurs throughout the United States but is most common in states surrounding the Gulf of Mexico.

    Equine Infectious Anemia is diagnosed by a blood test called the "Coggins test," which is named after Dr. Leroy Coggins, who developed the test. It is the law that horses must be "coggins" tested every twelve months in order to move from one property to another (this includes: shows, boarding, trail riding, and taking a "quick" trip down the road). Because people choose not to test their horses, there is great potential for outbreaks of the disease.