02/09/2026
🩸 We are sure your social media feed has posts about more positive EIA horses across the United States. As a horse owner, you have your veterinarian out for a yearly physical and dental exam, administer vaccinations, and pull blood for a Coggins test. But what is EIA?
🩸EIA is Equine Infectious Anemia, is caused by the Equine Infectious Anemia Virus. It only affects equids. Most infected horses are asymptomatic. The incubation period ranges from a week, 45 days or even longer.
Clinical Signs of Acute Infection:
🌡️ Fever
🤢 Inappetance
🪦 Sudden death
Clinical Signs of Chronically Infected Horses:
🏋🏻♀️ Weight loss
🐴 Ataxia/weakness
🩸 Anemia
🦵Swelling of the legs, chest and ventral
abdomen.
🩸 Once a horse is infected they serve as a lifetime reservoir for potential transmission. The most common type of transmission is vector; however, other types of transmission include iatrogenic (through contaminated needles, syringes, surgical instruments and blood transfusion from an infected horse etc.), and even reports of EIA transmission from mare to foal and stallion to mare.
🩸 Unfortunately, there is no known treatment for EIA nor vaccine for the prevention of this virus. And once horses are infected they become lifelong carriers of EIA which poses a risk of infection to other horses. The only options for an EIA infected horse is euthanasia or lifetime quarantine and isolation at least 200 yards away from non-infected horses.
🥼 What is a coggins test?
The test is named after a virologist named Leroy Coggins who developed EIA testing. A coggins test is a diagnostic blood test used to identify the presence of antibodies for EIA. EIA testing is A positive test indicates the presence of EIA-specific antibodies. The ELISA test can detect antibodies earlier than the AGID test: however, it is important to note that an AGID test be run to confirm the positive ELISA test due to the ELISA test may produce false positive results. The laboratory will report a positive test result to local state or federal animal health officials within 24 hours of the result. ElA is a regulated disease in the U.S. The animal health official will locate the positive horse, quarantine the horse, and obtain a second sample for confirmatory testing.
🩸 How do we protect horses from contracting the EIA virus?
We protect horses by practicing our due diligence when it comes to veterinary procedures, administering blood products, sterilizing surgical instruments, biosecurity measures and more.
📸: Dr. Cara Rosenbaum pulling blood on a Chincoteague Pony. Yes, they even get a yearly coggins done.
