The Texas Animal Health Commission (TAHC) has issued a temporary waiver on the requirement to test Thoroughbreds for equine piroplasmosis before they can enter a sanctioned racetrack in that state, effective Jan. 31.

Piroplasmosis testing remains a requirement for Quarter Horses at sanctioned racetrack facilities and for all horses regardless of breed at unsanctioned racetracks, the TAHC said.

Equine piroplasmosis is a tick-borne protozoal infection of horses. At least one species of tick, Amblyomma cajennense, has proved capable of transmitting the blood parasite. The disease can also be spread by unsafe animal husbandry practices such as sharing needles or equipment that is contaminated with blood.

While piroplasmosis can be a fatal disease, many horses display vague signs of illness, such as fever, lack of appetite, or jaundice.