We see mostly dogs and cats at good old KVC, so this is an unusual picture. Saturday afternoon we had 22 horses on the lot at one time. The trailers are scrambled around, so I couldn’t really get everybody lined up for the group picture (althought the short horses are in front). They were all here for their spring Coggins Test.
The test is named for Dr.Leroy Coggins, who developed it. It tests for the presence of the virus that causes Equine Infectious Anemia (aka, E.I.A., "Swamp Fever"). The virus often affects horses in much the same way that HIV affects people. The horse is unthrifty, won’t hold weight, doesn’t shed his winter hair, has trouble healing, and just generally ADR (technical abbreviation for "Ain’t doin’ right"). As you might expect from the name, they frequently become anemic (low on red blood cells). Sometimes this is so pronounced that the animal becomes weak and disoriented from a lack of oxygen (not enough red blood cells to carry it around the body). I have taken a blood sample from one horse (in the advanced stages of the disease) who was so anemic that his blood looked like Kool-aid: you could read through it.
There is no preventive vaccine for the disease and no effective treatment to cure it. Infected horses can remain carriers for years before they show outward signs (sort of like Magic Johnson’s dating career before his HIV diagnosis went public). The disease is transmitted by the bite of large, blood-feeding flies, such as horse-flies and deer-flies (the tabanid family).
As you can imagine, wherever large numbers of horses congregate, so do large numbers of horse-flies. If your horse is nice and healthy, you really wouldn’t want someone to bring in a carrier of E.I.A. It would be no time before they would want to share your horse-flies, and the next thing you know, your horse becomes a carrier, condemned to an ugly and premature death.
Since we can’t prevent this disease or cure it, the best we can do is to identify the carriers and be sure that they are quarantined away from other horses. That’s why you have to have your "I passed my Coggins Test" paper with your horse’s picture on it when you arrive at a horse-show, trail-ride, or horse-sale (also when you sell your horse, even to the guy next door). That’s why lots of horses show up for blood-tests as soon as spring is in the air.
There’s one weak point in the program, though. The incubation period (time from getting exposed to the germ until it shows up in the blood test) is two weeks. Most events ask for a blood test in the last six to twelve months. It becomes obvious that an old, moldy blood-test result may not reflect the horse’s current disease (or disease-free) status. If I were buying a horse, I’d have to make the purchase conditional on his passing a fresh, new blood-test, preferably after fly season, in the winter.