The California Department of Food and Agriculture (CDFA) confirmed a 3-year-old Quarter Horse stallion on a Riverside County, California, premises as positive for equine infectious anemia (EIA) May 2 while being tested for interstate movement to a racetrack. The horse originated from Tulare County.

As a result of the positive test, 27 exposed horses at the Riverside County facility and 34 exposed horses at the Tulare County facility are now under official quarantine. All Riverside County premises horses have tested negative and will remain under quarantine until retesting in 60 days. Test results for the Tulare County horses are pending. CDFA officials are investigating whether any other horses were exposed.

The Equine Disease Communication Center released this information on May 5, 2022.

About EIA

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;
• Fever;
• Depression; and
• Anemia.

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.