piroplasmosis in tennessee

Animal health officials have confirmed nearly two dozen cases of piroplasmosis in Tennessee horses. The state veterinarian’s office is investigating the equine piroplasmosis (EP) outbreak in a group of racing Quarter Horses in Middle Tennessee.

Thus far, 22 horses residing at five locations in Bedford, Rutherford, and Williamson counties have tested positive. All the horses are quarantined and being treated.

EP 101

Equine piroplasmosis is a parasitic infection of equids that can be spread naturally to equids by ticks or, more commonly, 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.

It can take as long as 30 days for an infected horse to test positive for the disease after exposure. Clinical signs of the disease include fever, anemia (a low red blood cell count), anorexia, depression, swollen abdomens, labored breathing, and jaundice. Some infected animals can carry the disease without showing any clinical signs. Horses that test positive for the disease are quarantined and could ultimately be euthanized.

In EP-endemic countries most horses become infected within their first year of life, and their fatality rate (5-10% of affected horses) is significantly lower than that in naive horses transported to endemic areas (which can exceed 50%). Australia, Canada, England, Iceland, Ireland, Japan, and the United States are the only countries worldwide where EP is not endemic. Cases of the disease do, however, appear sporadically in the United States.

Horses will not transmit the disease to other horses through casual contact. However, it is critical that horse handlers practice good biosecurity. If a needle is required, use a new sterile needle and syringe on every horse and clean and disinfect all equipment that may be contaminated with blood.

Some states and equine competitions require EP testing for entrance. If you plan to travel with your horse, check with the receiving state for current import requirements.


piroplasmosis in tennessee
piroplasmosis in tennessee