Although Equine Piroplasmosis is not common in the United States, AQHA is announcing testing requirements for the disease because international horse travel necessitates precautions.
Currently racetracks in 11 states require negative piroplasmosis tests before horses are allowed onto the facility. Beginning July 1, all horses entering the grounds for any AQHA world championship show will also be required to present a negative certificate dated within six months.
Equine piroplasmosis is a blood-borne protozoal infection. There are two different protozoa involved, named Babesia caballi and Theileria equi.
The parasite attaches to the red blood cells, the body recognizes there’s something wrong with that blood cell so it takes it out of circulation,” explained New Mexico State Veterinarian Dr. Dave Fly. “This bug’s growing on the blood cells, the spleen and liver are grabbing those blood cells trying to take them out so you go into what is called a hemolytic crisis. Animals can die, or they survive the acute phase and come out the other end as a chronic carrier.”
EP is transmitted from horse to horse through blood contact. “There are three populations of EP that we’re concerned with right now in the U.S.,” said Oklahoma State Veterinarian Dr. Becky Brewer-Walker. “They include the natural transmission via ticks and a small percentage of horses imported into the United States prior to changes in required testing protocol."
"However, the area of greatest concern is iatrogenic spread, or by people. We are seeing a spread of the disease to a large extent in Quarter Horse racehorses and some Thoroughbreds. These cases are almost all due to risky practices and poor biosecurity, disease spread horse to horse by the managementof the people."
If a horse is positive, the only options currently available are permanent quarantine or euthanasia.