On March 21, a 21-year-old mule in Fresno County, California, was confirmed positive for Equine Infectious Anemia (EIA). The mule is asymptomatic and being tested prior to interstate movement. Now, the mule is quarantined on her home premises with six potentially exposed equids (one additional mule and five horses).
None of the equids have had a show or travel history in the past six months. An epidemiological investigation is ongoing, but transmission is suspected to be via natural vectors such as biting flies.
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.