Kristi Schumacher spends time with her horse

Kristi Schumacher and the love of her life, her Paint mare, Shone, spend a quiet moment together.

This time of year we are running a lot of Coggins tests on horses that are traveling out of state or going to performances that require such testing.

But what is this test actually looking for? Here are the details:

Coggins Test

Coggins is a blood test for the diagnosis of Equine Infectious Anemia (EIA) named after the test’s developer, Leroy Coggins. This test uses serum that is spun off from whole blood. If the horse has EIA, the serum will contain antibodies that will be picked up by the test and be shown as positive.

Equine Infectious Anemia (EIA)

Equine Infectious Anemia is a viral disease that can be fatal. It is blood-borne meaning that it can be spread by blood-biting insects such as flies or by needles. Horses never clear the infection and remain able to infect other horses for their whole lives.

Clinical signs can vary from a slight fever to weakness, weight loss, and disorientation. Horses develop an anemia which means having too few red blood cells. Some horses die very rapidly whereas others become persistent carriers of the disease and hardly show any signs.

Why test for EIA?

Before 1975 the United States lost thousands of horses every year due to EIA. Since testing started, losses have been nearly negligible. EIA can mutate, which makes creating an effective vaccine very difficult and it’s one of the reasons why there is no vaccine available. No treatment has been discovered for EIA.

Where can I have my horse tested for EIA?

The first step is to make an appointment with your local veterinarian. They will draw a blood sample and take down your horse’s information.

There are several state labs across the country that veterinarians can send serum to for Coggins testing. Some veterinary clinics – Prairie View Veterinary Clinic included – have gone through extra training to become certified and can run their own Coggins tests.

It typically takes around one to two days to get results back from a state lab whereas we can have results within hours if we run them at our personal lab. These test results will be valid for one year.

How close to home have we found EIA recently?

On April 8, 2019, EIA was found in four horses in Polk County, Iowa. Other states that have had cases within the last year include Colorado, Florida, Georgia, Maryland, North Carolina, Oklahoma, Oregon, Tennessee, Texas and Wyoming.

Even though most of these cases seem to be far away from home, remember that horses travel every day. In June, Huron, South Dakota, will host the National Junior High Finals Rodeo in which more than 1,000 horses will travel to South Dakota from as far away as Mexico, Hawaii and Canada.

What happens to Coggins positive horses?

The state and federal veterinarians will be contacted immediately along with strict quarantine of the herd. More tests will be performed to make sure the horse is positive. After a positive is confirmed, the horse must either be euthanized or remain in isolation for the rest of its life.


Although it may seem like a pain to get your horses into the veterinarian for their annual Coggins test, it is very important for the health of horses throughout the United States. Thanks to states for requiring the test and for many shows requiring the test, we are able to keep EIA out of our horse herds.

Questions? Send email to Eric Knock, DVM, at or send mail to 321 E. 14th St., Miller, SD 57362. Eric Knock owns and operates Prairie View Vet Clinic in Miller, Redfield, Wessington Springs and Highmore, S.D.