Planning a trip abroad? Grab your passport, buy a ticket, and pack your bags. Whoa--not if you are a horse.

When a horse crosses an international border, the country the horse is traveling to requires proof that the horse won't threaten the health of the resident equine population. The University of Kentucky Maxwell H. Gluck Equine Research Center is often sought for research-based information that will define appropriate procedures to safeguard horse health. This research is very important, because horses travel more than any other animal species (for competition, breeding, and change of ownership, among other reasons).

The movement of horses internationally is underscored with the upcoming Alltech FEI World Equestrian Games (WEG) Sept. 25-Oct.10 at the Kentucky Horse Park (KHP), when about 750 horses representing 62 countries will ship to the Bluegrass. This isn't the first event for which many horses have been shipped to the United States; hundreds of horses shipped into Georgia for the 1996 Olympic Games. One of the most pressing issues, then and now, is equine piroplasmosis, a disease of Equidae (horses, donkeys, mules, and zebras) caused by two parasitic organisms, Theileria (Babesia) equi and B. caballi. The blood-borne disease is usually transmitted to horses by certain tick species, but it can also be spread via contaminated needles. But since the disease is transmitted only by exposure to infected blood, it's easier to control than many other diseases.

Once a horse contracts piroplasmosis, clinical signs appear in seven to 22 days. Cases can be mild or severe, depending on the amount of the organism in the horse’s blood. An acute case can have fever, anemia, jaundiced mucous membranes, a swollen abdomen, and labored breathing. A roughened hair coat, constipation, and colic might also be seen. Milder cases appear weak and inappetent. Up to 20% of infected horses can die and survivors become carriers—they carry the parasite even though they aren't ill. They can, however, pass it to other horses via ticks that bite first the infected horse, then an uninfected one.

Piroplasmosis could have been a major roadblock in bringing the WEG to Kentucky. Since the disease needed thorough evaluation, WEG organizers asked Gluck researchers for advice. Together with Rusty Ford, Kentucky Department of Agriculture's equine programs manager in the state veterinarian's office, they studied the problem.

"Helping get research-based answers is the hall­mark of a land grant university; so is teamwork," said Nancy Cox, PhD, associate dean for research and director of the Kentucky Agriculture Experiment Station. "The entomologists and vet­erinarians that teamed with our partner state agency worked to safeguard horses from all over the world, as well as those in Kentucky."

Lee Townsend, PhD, a professor of entomology at UK, conducted surveys of ticks at the KHP. The research provided valuable information, and a follow-up survey was recently conducted leading into the Games. The outcome of these investigations indicated that the risk of equine piroplasmosis being transmitted at the Horse Park was minimal. Beyond that, the American dog tick, which can serve as a vector of equine piroplasmosis, becomes dormant in the month of September.

Ticks are found in tall grass and undergrowth. So as an effective way to avoid ticks at the Horse Park, facilities management will keep grass short in areas where horses will compete.

Equine infectious disease researcher Peter Timoney, MVB, PhD, FRCVS, Frederick Van Lennep Chair in Equine Veterinary Science at Gluck, said, "There are large economic risks" if countries do not enforce regulations. But the regulators need solid research on which to base their regulations.

The USDA and state regulators worked with the Gluck Center and the department of entomology to formulate safeguards based on risk assessment that allow more freedom of movement of participating horses. Horses testing positive for piroplasmosis are given a 90-day temporary entry permit and kept separate from horses that are negative for antibodies to either causal agent of equine piroplasmosis. Most of the international horses will remain in Kentucky less than 90 days.

Diana Jividen is an editorial officer in Agricultural Communications Services at UK.

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