The California Department of Food and Agriculture (CDFA) has verified that a 7-year-old Quarter Horse gelding in San Benito County has tested positive for equine infectious anemia (EIA). Another horse on the same farm may have been exposed but initially tested negative. This horse will remain quarantined until it undergoes the required 60-day retest by the CDFA and USDA.
Epidemiological tracing has connected the infected horse to other California locations with recent EIA cases. The CDFA is actively monitoring the situation on-site.
EDCC Health Watch is a marketing program by Equine Network that utilizes information from the Equine Disease Communication Center (EDCC) to create and distribute verified equine disease reports. The EDCC is a nonprofit organization supported by industry donations to provide open access to infectious disease information.
About EIA
Equine infectious anemia is a viral disease that targets horses’ immune systems. The virus spreads through the exchange of body fluids from an infected to an uninfected animal, often through blood-feeding insects like horseflies. It can also be transmitted through blood-contaminated instruments or needles.
A Coggins test screens horses’ blood for antibodies that indicate the presence of the EIA virus. Most U.S. states mandate horses to have proof of a negative Coggins test for interstate travel.
Once a horse contracts EIA, it remains infected for life and can spread the disease. While not all horses display symptoms, those that do may show:
- Progressive body condition loss
- Muscle weakness
- Poor stamina
- Fever
- Depression
- Anemia
There is no vaccine or cure for EIA. An infected horse must either be euthanized, die, or be placed under strict quarantine conditions (at least 200 yards away from unaffected equids) for life.

