15 race horses test positive for equine piroplasmosis

September 14, 2016

Human use of contaminated equipment or product is the main risk of transmission.

Getty ImagesMore than a dozen Wyoming race horses are infected with equine piroplasmosis (EP), according to a Wyoming Livestock Board press release.

The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) notified Wyoming State Veterinarian Jim Logan, DVM, Aug. 25 that a California race horse of Wyoming origin had tested positive for EP.

Logan then partnered with the agency and with the Wyoming Pari-Mutuel Commission to establish quarantine and to conduct testing on horses associated with the infected animal. According to the release, 13 additional horses belonging to one owner in Wyoming tested positive, as well as one horse belonging to an owner from Utah.

EP is caused by one of two protozoan parasites-Theileria equi or Babesia caballi-and can spread to horses through ticks or through contaminated needles, syringes, surgical equipment or products. Clinical signs include fever, reduced appetite, malaise and increased pulse rate and respiration, but horses can carry the disease without showing signs.

The infected horses remain under quarantine while Logan and staff work with the owner to determine their futures. Infected horses can undergo the time-consuming treatment while quarantined, but the high cost must be covered by the owner. Other options, according to the release, include permanent quarantine or euthanasia.

Because Title 9 of the Code of Federal Regulations does not prohibit intra-state movement of animals exposed to EP, the Wyoming Livestock Board may allow the transport of negatively tested animals to other Wyoming race tracks.

“We are not concerned about horse-to-horse transmission of this disease,” Logan said in the release. “The transmission risk of concern is from human (trainer/owner) use of contaminated equipment or product among horses.”

The Wyoming Pari-Mutuel Commission has issued an order requiring all horses to have a negative Theileria equi cELISA test within 12 months of entering a sanctioned race track in Wyoming.

Logan and USDA APHIS are working with the Wyoming State Veterinary Laboratory to ready it for EP testing. In the meantime, veterinarians can send samples to Colorado State University Laboratory, National Veterinary Services Laboratories or other approved laboratories, according to the release.