CHEYENNE, Wyo. – A horse illegally moved from Colorado to Wyoming has resulted in the Wyoming Livestock Board quarantining nine total premises after it was found the horse was positive for Equine Infectious Anemia. That horse was returned under quarantine to Colorado.

“We do not have an infected horse in Wyoming to our knowledge,” said Wyoming State Veterinarian Dr. Jim Logan, “but we have many EIA-exposed horses.”

Wyoming Livestock Board’s investigation has led to the quarantining and testing of approximately 55 head of horses that were potentially exposed to the positive horse before it was known that it was infected. Forty-one were exposed at a Sweetwater County premise where the horse was sent illegally from Colorado. The remaining horses were exposed to the same horse in Colorado prior to being shipped to Wyoming. All but two of these exposed horses were imported illegally into Wyoming as well. 

The quarantined premises are located in Sweetwater, Lincoln, Teton, Park and Fremont counties in Wyoming. An additional four horses and three premises are still being traced in Natrona and Laramie counties.

In addition, horses have been traced to at least 19 other states with at least 200 horses having been moved from the Colorado facility where the infected horse originated.

EIA is a viral disease spread by biting flies. The virus causes anemia but can also be carried by asymptomatic horses that can infect the vectors and cause other equine exposure. The virus is one that incubates very slowly in the host animal and can take up to 60 days from exposure to show a positive test if transmission has occurred. There is no vaccine and no treatment for the disease, and horses that test positive are required to be euthanized or placed under quarantine for life in a screened stall to avoid further exposure risk. 

“The disease is found in many states, and we have had previous cases in Wyoming over the years,” said Logan.  “The source, distribution and receivers of the horses have been identified, and education and investigation continues.”   

More information about EIA is available at the Equine Disease Communication Center (EDCC) website at http://www.equinediseasecc.org. All state requirements for shipping livestock interstate can be found at www.interstatelivestock.com. For brand requirements, the state brand agency should be contacted directly. In Wyoming, brand inspections are required at change of ownership and to move all horses, sheep and cattle across county and state lines. More information can be obtained by calling (307) 777-7515.