On June 22, a 5-year-old Quarter Horse gelding in Los Angeles County, California, was confirmed positive for equine infectious anemia (EIA). The horse, which is used for racing, was not displaying clinical signs; he was tested prior to returning to the racetrack. The gelding is now being quarantined at his home premises, where eight additional horses are exposed. The exposed horses have been tested for EIA with results currently pending.
Epidemiological tracing is ongoing, but transmission is suspected to be iatrogenic and exposure primarily limited to a subset of an unsanctioned racing program.
EDCC Health Watch is an Equine Network marketing program that utilizes information from the Equine Disease Communication Center (EDCC) to create and disseminate verified equine disease reports. The EDCC is an independent nonprofit organization that is supported by industry donations in order to provide open access to infectious disease information.
Equine infectious anemia is a viral disease that attacks horses’ immune systems. The virus is transmitted through the exchange of body fluids from an infected to an uninfected animal, often by blood-feeding insects such as horseflies. It can also be transmitted through the use of blood-contaminated instruments or needles.
A Coggins test screens horses’ blood for antibodies that are indicative of the presence of the EIA virus. Most U.S. states require horses to have proof of a negative Coggins test to travel across state lines.
Once an animal is infected with EIA, it is infected for life and can be a reservoir for the spread of disease. Not all horses show signs of disease, but those that do can exhibit:
- Progressive body condition loss;
- Muscle weakness;
- Poor stamina;
- Depression; and
EIA has no vaccine and no cure. A horse diagnosed with the disease dies, is euthanized or must be placed under extremely strict quarantine conditions (at least 200 yards away from unaffected equids) for the rest of his life.