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Coggins Testing





Understanding a Coggins Test


Most horse owners have had some experience with a Coggins test. It seems pretty simple; their horseʼs blood is taken, picture drawn and approximately a week later theyʼre handed a yellow piece of paper that states their horse is negative. But what does all of it mean and why does your horse need to be tested? Read on a learn more about Coggins testing.


What is it testing for?

A Coggins test is utilized for the diagnosis of Equine Infectious Anemia (EIA), also know as swamp fever. EIA is caused by Equine Infectious Anemia Virus (EIAV).


Why is it called a Coggins test?

The very first test for diagnosing EIA was developed by Dr. Leroy Coggins of Cornell University in 1970. In 1973, the United States Department of Agriculture (USDA), made the Coggins test the official test for EIA.


Who performs a Coggins test?

Only a licensed USDA accredited veterinarian with can draw blood from the horse and fill out the necessary paper work. The test is performed at a federally approved diagnostic laboratory.


What are the symptoms of EIA?

Horses that become infected with EIA have one of three clinical syndromes: (1) acute infection, (2) chronic infection, or (3) inapparent carrier. Horses that are acutely infected show signs of fever, lethargy and anorexia. These signs progress to include weight loss, ventral edema and anemia in the chronically infected horse. Inapparent carriers are horses that will test positive, but are not showing any outward signs of disease. They will remain infected for their entire life, and therefore, remain a threat to other horses.


How does a horse become infected?

EIA is not contagious to humans and it is not directly contagious from horse to horse. Transmission of EIAV occurs by the spread of blood from an infected horse to that of a non-infected horse. This occurs most commonly through blood-sucking insects, such as horseflies and deer flies. The virus can also be transmitted through improperly sterilized needles, surgical instruments and other blood contaminated material. Therefore, do not share needles between horses.


What happens when a horse tests positive?

There is no specific treatment to target the virus. Treatment of the infected animal is supportive (fluids, non-steroidal anti-inflammatory drugs and nutritional support) to help them through a febrile episode.


Horses that test positive are confirmed with a second positive test. There are three  options for EIA positive horses: (1) permanent identification by tattoo or brand and  quarantined for life from any equine species within 200 yards, (2) transport to a federally  approved research facility or slaughter house, or (3) euthanasia. “Exposed” horses  remaining at the facility must be retested every 30-60 until no new cases are found. 

What are the official rules?
1). Horses remaining within the state of Maine are required to have a Coggins test  performed every 3 years. 
2). Horses entering or leaving the state of Maine are required to have a negative  Coggins test within one year of entry/departure date. **Horses are also required to  have a certificate of veterinary inspection within 30 days of departure. 
3). Horses exporting to Canada are required to have a negative Coggins test within  six months of departure date. **Horses are also required to have a Canadian Health  Certificate within 30 days for entry into Canada.

What are other times a Coggins test is recommended?
1). Require a negative Coggins test as part of EVERY prepurchase examination.
2). Require all new arrivals on a farm to have documentation of a recent negative  Coggins test, and test all horses on the farm annually. 
3). Horse shows, fairs, national and state parks may require more frequent testing. Itʼs  important to check these requirements and allow enough time for the test to be  performed before the event takes place. 


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