Wyoming horses quarantined following EIA exposure

A horse that recently traveled from Colorado to Wyoming and back again has tested positive for equine infectious anemia (EIA), according to the Equine Disease Communication Center (EDCC).

Last week, “the Wyoming Livestock Board was notified by the Colorado Department of Agriculture that a horse which tested positive in Colorado for EIA had been moved to Sweetwater County, Wyoming,” the EDCC said. “While the horse was tested in Colorado, it was shipped prior to test results (being) reported and without an interstate certificate of veterinary inspection.”

The EDCC said the horse returned to Colorado, but a there are a number of Wyoming horses quarantined following EIA exposure. Animal health officials in that state have quarantined 41 exposed equids on the premise at which the horse was residing in Wyoming.

“The horses exposed to the positive Colorado horse for six days and will be tested initially on August 30 and again sixty days later,” the EDCC said.

Another two exposed horses from the initial Colorado premises were shipped to another facility with negative EIA tests, the EDCC said. They have been quarantined and will be retested in 60 days.

None of the affected equids are racehorses, the EDCC said.

EIA 101

Equine infectious anemia is a viral disease that attacks horses’ immune systems. The virus is transmitted through the exchange of body fluids from an infected to a noninfected animal, often by blood-feeding insects such as horseflies. It can also be transmitted through the use of blood-contaminated instruments or needles.

A Coggins test screens horses’ blood for antibodies that are indicative of the presence of EIA. Most U.S. states require horses to have proof of a negative Coggins test in order to travel.

Once an animal is infected with EIA, it is infected for life and can be a reservoir for the spread of disease. Not all horses show signs of disease, but those that do can exhibit:

  • Progressive condition loss;
  • Muscle weakness;
  • Poor stamina;
  • Fever;
  • Depression; and
  • Anemia.

There is no vaccine and no cure. A horse diagnosed with EIA dies, is euthanized, or must be placed under extremely strict quarantine conditions (at least 200 yards away from unaffected equids) for the rest of his life.