The Coggins Test and what it means for your horse.


The Coggins test is for Equine Infectious Anemia (EIA), a horrible and contagious disease.


jump to shopping


  • Most of us sort of know what a Coggins is…sort of…but it’s more than just a blood test. It’s also a way to help prevent a horrible disease without a cure from spreading to other horses. The Coggins test detects antibodies to Equine Infectious Anemia (EIA). There is also no vaccine, so prevention is best.


  • The virus that causes EIA is spread by horseflies and other biting insects. The flies bite one horse, then bite another. The virus only lives with the insect for less than an hour, so the horse-to-horse transmission must happen when horses live in close proximity.


  • EIA causes fever, anemia, swelling of the abdomen, stocking up, weight loss, and muscle wasting. This can lead to organ damage and secondary infections, and eventually death.


There are three stages of EIA – the acute, the chronic, and the carriers.


  • Acute cases are often vague, with a fever, depression, and no appetite. This looks like a lot of other diseases, and a Coggins test will only come positive after 6 weeks. Most acute cases die within a month.


  • Chronic EIA also has a fever and weight loss, along with small hemorrhages of the mucous membranes. Chronic horses may have acute episodes that come and go. They will test positive as the expected lifespan is about a year. The horse’s underside and legs often swell also.


  • The carrier horses are largely asymptomatic. They also carry the disease for life and can transmit it to other horses. You will likely not see any signs, but the test will be positive.


example of a coggins done digitally

The results. Previously, your vet had to draw your horse and his markings. Now, it’s digital.


How to prevent EIA



  • You must also be smart about where you bring your horse. Shows, new boarding facilities, even group trail rides are all places where a horse could be infected. Some shows (not all) require a negative Coggins test within 6 months or a year. Some boarding barns do, as well.


coggins test sign at a horse show

I spotted this Coggins requirement at a horse show.



  • As there is no cure, and the options for a horse with a positive Coggins are tragic. Euthanasia is often the solution. In some areas, you might be able to have your horse enter a lifelong quarantine, which requires him to be branded and come no closer than 200 yards to another horse. This option is devastating for any creature that is, by nature, a herd animal.


vet taking blood from the jugular vein of a horse

It’s a simple blood test!


Be smart about transporting your horse, and be diligent about monitoring his health!


go shopping button for horse products


Stock up here for your horse supplies! As an Amazon Associate, I earn from qualifying purchases, but it’s ZERO extra cents to you.  You can also visit my Amazon storefront here:  PEG storefront.

Digital Pet Thermometer - Waterproof, Fast and Accurate Measurements in 20 Seconds
$8.99 $7.99

Every horse owner needs a digital thermometer for fast and accurate vital signs

07/08/2024 06:07 pm GMT


Thank you!