Saturday, July 5, 2008

Exactly what is Coggins?

Coggins is actually just the name of a test that is performed on horses. The name comes from the veterinarian who invented the test in the 1970's, Dr. Leroy Coggins.

The test screens the blood of a horse to determine if the horse has the virus that causes Equine Infectious Anemia or EIA. EIA is also known as Swamp Fever because it is common in hot, muggy environments.

There is no cure for EIA. It is contagious and can be fatal. The death rate is estimated to be 30% to 50% of horses who are infected with the virus. (That means about 50% to 70% survive the disease). If the horse survives, they will continue to be a carrier of the disease for the rest of their lives and therefore a danger and a threat to any other horses that they come in contact with. This is why many states require mandatory Coggins tests before a horse can be brought across state lines and why so many horse professionals, breeders, etc. require a negative Coggins test before a horse is bought, sold, moved into a new barn, allowed to enter a horse show or other event, auction, etc. Laws vary from state to state on when a horse has been exposed. Some states say a horse has been exposed to an infected horse if within 200 yards and some say within 3 miles! That should be a good indicator of how contagious the disease may be and how fearful horse owners and professionals are of the disease being spread.

There are three stages of the disease: acute, chronic and carrier (or "inapparent", meaning the horse shows no signs of the disease).

In the acute and chronic stages of EIA, the symptoms are:

  1. High fever (105 - 108 degrees)
  2. Weakness and lethargy
  3. Refuses food
  4. Weight loss
  5. Irregular heartbeat
  6. Swelling in the chest, stomach or legs.

EIA is transmitted by biting insects such as horseflies and deerflies but can also be transmitted by using contaminated needles or veterinary and dental equipment. That should not be much of a concern since veterinarians and equine dentists are aware of this danger and I'm sure all (or at least most) are sure to sterilize their equipment after each horse is treated. (However, if you have any doubts, never be afraid to ask your vet or equine dentist).

Because of the danger and infectious nature of EIA, it is highly recommended that any horse that tests positive for EIA be immediatly put down (euthanized). Always ask the vet for an immediate recheck if you get a postive result from the Coggins test. (This is common and expected). The only other option is lifetime quarantine which wouldn't be much of a life for a horse since they are herd animals and not a guarantee that the horse wouldn't infect other horses. After all, flies will continue to feed on the EIA postive horse and will travel to other areas.

The things you can do to help prevent the spread of EIA is:

  1. Always ask for a recent Coggins test (no more than 30 days old) on any horse you buy or adopt.
  2. If they don't have a recent Coggins test, keep them quarantined until you can get one! (Do not take them around any other horses or other equines (donkeys, mules, etc.) until you can get them tested)
  3. Get a Coggins test on all of your horses annually.
  4. Limit the chance that your horse will be exposed to the disease - Don't take your horse to any event unless you know for certain that event requires a negative Coggins test for all entrants.
  5. Separate and quarantine any sick horse that shows the possible signs of EIA and call the vet.
  6. Never share needles between horses. Always safely dispose of needles after each use.
  7. Do what you can to keep the fly population down: keep the horses area as clean and free of manure as is reasonably possible; use fly repellents, sprays, fly traps, etc.
  8. Follow state laws regarding Coggins testing. For information on state laws, you can call the U.S. Department of Agriculture at 1-800-545-8732 or check out this website for a list of all states: (you will be able to click on your state):

There is no vaccine that will prevent EIA. The good news is that because of strict laws regarding Coggins tests and the efforts of conscientious horse owners, EIA is rare in the United States.


Isabelle Zita said...

Informative post; I had been wondering why the Coggins test was named that and why the test was so common!

Also, neat blog. I'll have to follow it. :)

~ Melanie ~ said...

Thank you Isabelle! I'm glad you found it helpful. :)

Please feel free to email me your horse questions and I'll do my best to answer them or at least point you to someone or someplace that can. (Scroll down to the "About Me" section and click on "View my complete profile" to send me an email) I look forward to hearing from you! ~Melanie