Coggins: What is it and why do we test annually?


Coggins season is upon us!  But what is Coggins and what does it entail?

Coggins is an infectious disease clinically called Equine Infectious Anemia or EIA.  It is often referred to as Coggins because the scientist that developed the first effective and reliable test back in the 1970’s was Dr. Leroy Coggins.  To this day, Dr. Coggins’ test remains the gold standard for testing and is internationally accepted, even though there are other lab tests available. 

Dr. Leroy Coggins  1932 – 2013


EIA is a retrovirus similar to the human HIV virus.  It is transmitted by contact with bodily fluids such as blood, milk, and other bodily secretions or by blood sucking insects such as horse flies and deer flies.  As with the human HIV, EIA can not be transmitted by mosquitoes as they do not offer the proper body temperature to carry on the virus. Generally, yearly testing is required if you will be transporting your horse for any reason, but some states or organized shows may require a negative test within 6 months of importation.

A positive EIA test does not bode well for the affected equine.  According to the Kentucky Equine Research, most positive cases happen along the Mississippi River or in the southeast region of the U.S, but cases have been reported nationwide and internationally.  If a positive horse is identified it will almost always need to be euthanized because the quarantine conditions are so strict that they are almost impossible to comply with to prevent the spread of the disease.  There is currently no vaccine to prevent the spread of the virus, so annual testing is required or semi-annual if you have a busy travel schedule.

Yearly testing is a simple, quick appointment.  A licensed veterinarian will need to collect a small blood sample from the horse and then send it to the lab.  Most results are returned within 2-3 days along with a certificate for the owner so that they may provide proof if attending a show or just general travel.  When an owner requests a Health Certificate for travel, a current Coggins test must be on file with the completing veterinarian in order to validate the certificate.

A sample Coggins certificate. Similarly to the tabs for your license plate on your car, a Coggins certificate is a different color each year for quick reference of when the test was completed.

Here at Michigan Large Animal Associates, one of our veterinarians will collect a blood sample from your horse and bring it back to the clinic.  The office assistant will then place the sample in the centrifuge and spin the sample to separate the blood cells from the serum needed to complete the test.  Once this is complete, we need to fill out a form with the horse owner’s name and location, as well as the boarding barn’s location if the horse does not reside at home with the owner.  These forms must also include photos of the left, right, and front of the horse to be validated.  If a form is sent to the lab without this information the lab will reject it and a new sample will need to be collected and sent with a completed form.  This information will also be included on the official Coggins certificate you will receive after the testing is complete.  MLAA is then notified once testing is complete and we will send the results and certificate to the horse owner.



A Coggins test can be performed at any time of the year, but we typically see an influx of test requests in the spring as everyone is also completing their yearly vaccine schedule and before show & fair season really picks up.  Call us to schedule your Coggins test and spring vaccines today at 517-541-2238!

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