Three horses in California were recently confirmed positive for equine infectious anemia (EIA). The affected horses were located in Riverside and Los Angeles counties. 

In Riverside County, a 2-year-old Quarter Horse gelding was confirmed positive on a 60-day retest after three horses on the farm previously tested positive. The horse was euthanized. Twenty-one additional horses on the premises tested negative on their 60-day retest. The quarantine on this premises has now been released. 

In Los Angeles County, a 4-year-old Quarter Horse gelding and an 8-year-old Quarter Horse gelding were confirmed positive on March 20 and were euthanized on March 22. Ten potentially exposed horses on the premises have tested negative and will remain under quarantine until their 60-day retest. Exposure is suspected to be primarily limited to a subset of an unsanctioned racing population. 

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.

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.