With five horses dying from Eastern equine encephalitis over the last month, Maine’s harness racing community is taking steps to guard against the spread of the disease to pacing and trotting racehorses.
Instances of the fatal, mosquito-borne disease have been confined to farm and pleasure horses, but the risk of spreading to racehorses is a concern.
“We encourage all the horsemen to get their horses all their shots: EEE, rabies and two others,” said Ralph Canney, Maine State Harness Racing Commission state steward. “They have to have one test to be certified to race, but there’s no requirement for EEE inoculation.”
Denise L. McNitt, a doctor of veterinary medicine and the MSHRC’s veterinarian, says most young racing horses, especially on breeding farms, have already been inoculated against EEE.
“Most are very well vaccinated, but the older horses, it depends on the trainer and where they’re at,” McNitt said. “We’ve gotten a fair amount of inquiries about it and whether they should vaccinate their horse. I’m pretty aggressive about urging vaccinations and I think the word’s getting out there.”
McNitt said one concern is communication and publicity as many horsemen are just finding out about the infections and deaths, which occurred in horses who were not inoculated, according to Maine State Veterinarian Don Hoenig.
“He’s fairly reluctant to require specific vaccinations, but he is very vocal about urging owners to have their horses vaccinated if they haven’t already been,” McNitt said.
The disease occurs primarily in birds, but is spread to horses through infected mosquito bites. The risk of a human contracting the disease from mosquito bite is low and horses cannot pass it on to humans, according to McNitt.
Once the virus is contracted, symptoms include fever, aches, pains, and seizures. The disease is 30 percent fatal in humans and almost 100 percent in horses.
Harness horse owner, trainer and driver Shawn Thayer, who is training horses in Ellington, Conn., this summer for owner Irving Bork, says he has heard of no instances of the disease locally among horses of any kind.
“It’s mosquito infested where I am because we’re near a canal and the water level is very high for this time of year,” Thayer said. “I’m on a farm with 38 horses and we haven’t had a case or heard of one.”
Canney said communication and prevention are the most effective way of keeping the disease out of the racing community.
“Get vaccinated as soon as possible. It’s better to be safe than sorry,” he said.
In the meantime, McNitt is hopeful that cooler nights will decrease the mosquito population and eventually stamp out the outbreaks.
“The bird population is pretty well infested now, but with a few, cold nights or a couple of hard frosts, it will cut down on it quite a bit,” she said.
Thayer said he believes Connecticut and New York racehorses are required to be vaccinated against EEE, but he gets his horses all vaccinations to be safe.
“I’m training 18, three of which I own,” he said. “Of the 38 on the farm, only two are pleasure horses, but you have to be cautious.
“Racing horses are an investment and I’d rather pay for the vaccinations and not have to worry about the horses getting something.