Domestic horses depend on their owners to keep them healthy and safe from infectious disease. One disease owners should keep on their radars is equine infectious anemia (EIA), which can destroy red blood cells and cause weakness, anemia, and death.

“EIA is an infectious viral disease,” says Michelle Coleman, DVM, PhD, Dipl. ACVIM, assistant professor at the Texas A&M College of Veterinary Medicine and Biomedical Sciences, in College Station. “The most common mode of transmission of EIA is by the transfer of virus-infected blood-feeding insects, such as horse flies. It can also be transmitted through the use of blood-contaminated syringes, surgical equipment, or the transfusion of infected blood or blood products. Although uncommon, transmission can also occur through the placenta in infected mares.”

There is no treatment or safe and effective vaccine, available for this disease, so horses that positive for EIA must be isolated from other horses or euthanized. Some horses infected with EIA also do not show any signs of illness or disease, so it is important to constantly maintain good hygiene and disinfection principles, such as controlling insects in the horse’s environment.

All horses traveling across state lines must be tested for EIA and have a negative result within 12 months of transport. Furthermore, all horses sold, traded, donated, or entering a sale or auction must test negative for the disease. Fortunately, regulatory control of EIA has made this disease relatively uncommon in the United States.

Despite the disease becoming less common, Coleman reminded horse owners to be aware of EIA and routinely test all horses. With proper hygiene and effective health routines, horses across the nation can be kept safe from EIA.