What Is a Coggins Test and Why Do Horses Need It?

This is the season for annual boosters and vaccinations for horses - pleasure, pasture, or working. Vaccinations are a vital part of equine management. If they're incorporated into a regular program that includes deworming, a safe environment, ample clean water, and good hay and grain, both horse and owner should be set to enjoy productive and happy years together.

As I've stated before, and learned firsthand, vaccination does not prevent disease but it helps to minimize it and prevent the risk of infection. The most important of shots are tetanus, influenza, and those for encephalomyelitis (sleeping sickness). The other most responsible thing a horse owner should do is have an annual Coggins test.

Every year I'm asked about this, and as the world becomes more open to the potential threat of communicable diseases, it becomes more important we should adhere to guidelines that involve the safety of livestock. A Coggins test is a valuable tool.

So what is a Coggins test? It's a test in which a vial of blood is drawn from the neck of a horse and used to detect the disease called EIA Equine Infectious Anemia, also known as "Swamp Fever." This viral disease affects horses, ponies, mules, and donkeys. Once infected, the animals are infected for life. There is no vaccine, nor is there a cure. The animal dies or must be euthanized.

EIA is not contagious to humans, and it is not directly contagious to equines but it is spread by contaminated blood.

The transmission from horse to horse is usually via horse-flies, deer flies, and less frequently, mosquitoes. EIA is not the West Nile virus. Rather, in this case the flies, which potentially can hold infected blood in their mouths, will fly to another animal or herd mate to finish their meal, and bite again.

The first documented case was recorded in 1843 in France. The first case in America was in 1888 in Wisconsin and it was known then as the "equine relapsing fever." In 1891 an epidemic hit Wyoming and in 1947 the Rockingham Pace Racetrack in New Hampshire was devastated when 77 horses died. In 1970, Dr. Leroy Coggins, from Cornwell University, developed the first accurate laboratory procedure for diagnosis. The test, named after him, does not detect the virus, but does detect the presence of the antibodies in the animal's blood.

Since then the U.S. government has required that any animal imported to the country must have a negative test before admittance. Most laws dealing with EIA are established at the state level. A few states require a negative test in the last six months, but most accept those from the last 12 months.

Michigan requires an annual Coggins test. Horses coming from downstate may be stopped at the Mackinac Bridge and owners or handlers may be required to show proof of a negative Coggins. This is often in conjunction with the stopping of all transports hauling wood. Horse trailers may be stopped because of carrying wood shavings, as part of the Emerald Ash Borer insect crackdown, and regulatory officials have been alerted to the seriousness of EIA. The average cost for a

Coggins test is between $20 and $35 and it can only be performed by a licensed veterinarian who fills out a form to positively identify the horse. The blood test is then sent to a state testing laboratory. The report comes back to the veterinarian and then it is sent to the owner. Some laboratories directly send the report to the owner, but each veterinarian has a copy on file.

In any event, it's a good practice to have your papers on hand before trailering on the highways. Recently the following organizations have mandated proof of a current negative Coggins before any entries in shows or approved sales: the Michigan Farm Bureau, the American Quarter Horse Association, the American Paint Horse Association, the United States Equestrian Federation, the United States Dressage Association, the National American Reining Association, the National 4-H Association, and the United States Eventing Association.

Do not buy a horse unless you have proof of a current negative Coggins, or have it mandated as part of your purchase contract, even if you have to pay for it yourself.

Candice Dunnigan is an active member of the American Equestrian Association, the Waterloo Hunt, and the Mackinac Island Horsemen's Association. Seasonally she resides at Easterly Cottage.