The meaning of Coggins

Farm Forum

Written by Danielle Busselman under the direction and review of Dr. Rebecca Bott, Assistant Professor & Equine Specialist, SDSU Animal Science Department.

With our horses accompanying us to shows and summer trips, many have already consulted with veterinarians about vaccinations and health certificates. In that seemingly long list of required health inspections reads a test most of us see every year, the Coggins test. Although it appears as just one more item to check off, this test detects the presence of a very important disease circulating in the equine industry.

Equine Infectious Anemia is a viral disease that attacks all members of the horse family. Once introduced into the body it targets the white blood cells and attacks red blood cells while damaging organs. With internal health complications occurring, external signs can often times be overlooked. Without testing for Equine Infectious Anemia (EIA) it can be difficult to diagnose.

Equine Infectious Anemia presents in three different stages for diagnosis. First is the acute stage, which is very difficult to diagnose. Spreading of the disease is just beginning, and it starts damaging vital organs. Antibodies are difficult to detect by tests at this point. The chronic phase remains easier for clinical diagnosis. The animal has fever and may exhibit signs of depression, droopy head and ears, and anemia, characterized by loss of appetite and weakness. This phase is not continuous which results in flares of the symptoms. In the last stage, also known as inapparent phase, the flares subside and no more clinical signs are witnessed; the animal however will be a carrier for life.

The diagnosis process for EIA is fairly simple. The Coggins test, named after its discoverer, tests the blood for antibodies to EIA. The process begins when a veterinarian takes a blood sample and sends it to the lab for testing. Accurate records need to be kept as this disease is very contagious. When the veterinarian takes a blood sample the animal must be clearly identified; paperwork with the description of the animal must be kept for the veterinarian’s as well as the owner’s records.

The majority of cases that occur in the United States are linked to climate. The “hot zone”, which includes Virginia, Texas, Missouri, Illinois, Iowa, Minnesota, Wisconsin and South Dakota borders, provides an adequate environment for insects that carry the disease. Equine Infectious Anemia is transmitted by infected blood, and carriers include horseflies, deerflies, and other blood sucking insects.

There is currently no cure for EIA. Once a horse contracts the disease it will be carrier for life. We as owners have two options, the first one being euthanasia. The second option proves to be a more difficult task; the owner can keep the animal alive, however certain precautions must be taken. The American Association of Equine Practitioners lists specific rules for infected animals. The infected horse, by regulation, must be kept in quarantine 200 yards away from other non- infected horses, donkeys or mules and can travel no more than 3 miles away from the main facilities. In the end, many owners decide to humanely euthanize the animal because of the stress of caring for an infected horse, and the distinct probability of the disease being passed onto another horse.

Every test performed by your veterinarian has a significant purpose. Yes, for many of us these tests are viewed as just one more item to check off the health certificate and travel list. However, the meaning behind the test has a larger bearing in the health field than anyone can imagine. Understanding the full meaning behind that simple check mark is very important in the equine industry.

Danielle Busselman is studying communications and equine science and looks forward to a career in writing for an equine publication.