Fourteen racehorses from Wyoming, along with one in Utah, have tested positive for equine prioplasmosis (EP), the Wyoming Livestock Board announced Sept. 2.

On Aug. 25, Wyoming State Veterinarian Jim Logan, DVM, was notified by the USDA Animal and Plant Health Inspection Service (APHIS) that a Wyoming-origin racehorse had tested positive in California for EP. Subsequent testing of other horses in Wyoming that were associated with the positive animal revealed 13 additional infected horses involved that belong to one owner in Wyoming, as well as another horse belonging to one owner from Utah.

Soon after receiving news of the infected horse in California, Logan, along with USDA-APHIS and the Wyoming Pari-Mutuel Commission, establish quarantine, testing, and movement protocols for associated horses in Wyoming. These animals are currently under quarantine at the owner’s property.

“We are currently dealing with a horse disease in Wyoming that is specific to racetrack activities and is not a threat to the general equine population in the state,” said Logan.

Equine piroplasmosis is a parasitic infection of equids that can be spread naturally to equids by ticks or by humans to equids through contaminated needles, syringes, and treatment/surgical equipment and products. The causative agents of the disease are protozoan parasites called Theileria equi and Babesia caballi. Clinical signs of the disease include fever, anemia (a low red blood cell count), anorexia, depression, and jaundice. Some infected animals can carry the disease without showing any clinical signs.

Horses with EP can be treated under quara