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What Is Coggins Disease in Horses?

| Updated August 11, 2017

There is no such thing as Coggins disease. The Coggins test is a blood test that veterinarians use to diagnose horses who have contracted a disease called equine infectious anemia. Equine infectious anemia is a serious disease, which cannot be treated or cured. If you suspect your horse might be showing signs of equine infectious anemia, call your veterinarian immediately.

Equine Infectious Anemia

Equine infectious anemia is a serious and often fatal disease that is spread from horse to horse via biting flying insects such as horse flies and deer flies. It also may be spread by injection via contaminated needles or medical supplies. This disease is not contagious in that horses cannot spread the disease directly from an infected horse to a healthy horse.

Equine infectious anemia also may be referred to as swamp fever or horse malaria. If a horse is infected with equine infectious anemia, the disease will destroy its red blood cells.

Symptoms of Equine Infectious Anemia

Symptoms of equine infectious anemia include anemia, weight loss, loss of appetite, weakness, fever, lethargy, a loss of athletic performance ability, swollen legs and belly due to edema, depression, enlarged spleen and death. Some horses may appear to recover from their symptoms, only to have symptoms return periodically. Horses with equine infectious anemia can spread the disease through their blood, regardless of whether or not an infected horse is showing symptoms at the time.

Diagnosing Equine Infectious Anemia

The Coggins test was developed in 1970 by Dr. Leroy Coggins of the New York State College of Veterinary Medicine at Cornell University. The Coggins test is an agar gel immunodiffusion test that checks your horse's blood for the presence of equine infectious anemia antibodies. Prior to the development of this test, it was difficult and expensive to identify horses who were suffering from equine infectious anemia.

Coggins tests are legally required to be performed only by licensed veterinarians, who draw the blood and send it off to government approved laboratories to be tested for equine infectious anemia. The laboratory will return the results to your veterinarian along with a certificate that says whether your horse is negative or positive for the disease. Negative is considered normal. Your veterinarian is required to report any positive test results to state authorities as well as to the Department of Agriculture.

Other Considerations

Horses cannot be cured of equine infectious anemia and there is no effective treatment that will prevent the disease from continuing to affect the sick horse or spreading to other horses. Coggins tests are used to identify infected animals so that they can be separated from the general population to avoid spreading the disease to healthy horses. Separation may be done by putting the horse into a permanent, lifelong quarantine, donating him to a research facility that specializes in horses with equine infectious anemia or euthanizing the horse. Most affected horses are euthanized.

Most states require horse owners to have their horses tested annually or semi-annually for equine infectious anemia. Check with your local department of agriculture to find out what laws apply in your state. A negative Coggins test is required to participate at all equine events and for travel across state lines. Some states require a horse to have a negative Coggins while traveling within the state.