Your Horse's Coggins Test

A negative Coggins test for equine infectious anemia is important — and sometimes required. Here’s what you need to know.

- Eleanor M. Kellon

What if you knew of an equine disease that had no cure, no treatment, and in many cases would require you to destroy your horse if he became infected? You’d probably find that pretty scary.

Well, such a disease does exist, but luckily it’s rare enough that we tend to forget about it. Because the Coggins test has proved so effective, equine infectious anemia (EIA) receives very little attention these days. But it’s still around, and it’s still a killer.

Here, I’ll first go over the causes of EIA and explain how the virus spreads. Then I’ll tell you why getting a Coggins test for your horse is so important, especially if he’s on the road.

How EIA Spreads

Also known as “swamp fever,” EIA is caused by infection from a lentivirus, the same family of virus that causes acquired immune deficiency syndrome (AIDS) in people. However, people can’t get AIDS from the equine virus, nor can horses get EIA from the human virus.

EIA can’t be spread by casual contact. It’s usually transmitted via large biting flies, which carry virus-packed blood from an infected horse to a neighboring horse.