A smattering of new cases of equine infectious anemia in Alberta and Saskatchewan may intensify the pressure to implement new, and costly, measures to control the potentially devastating disease.
Four cases of the disease (typically called EIA or ‘swamp fever’) have been found in Alberta and two in Saskatchewan this year. The first three Alberta cases were in the Rocky View, Ponoka, and Grande Prairie areas and involved single animals while the latest, confirmed in May and made public earlier this month, involved seven horses in the Pincher Creek region. The Canadian Food Inspection Agency would not reveal details of the cases, except the three individual cases were discovered when the horses were tested “for a variety of reasons” (such as a condition of sale or because it was going to be exported).
“It’s a difficult situation,” said Dr. Renaud Leguillette, an associate professor at the University of Calgary’s faculty of veterinary medicine and a member of a national equine disease surveillance committee.
“It’s such a smart virus, that’s been here for centuries. It can hide, and will keep living quietly in a horse, which will act as a reservoir and a source of contamination for other horses. With wild, unchecked horses, EIA is not easy to eradicate.”
However, horse owners should not be alarmed, he added.
“A small reservoir does put the horse population at risk, but how high is the risk? People shouldn’t panic, because it’s a low-prevalence problem.”
- More on the Alberta Farmer: What is equine infectious anemia?
Equine infectious anemia is a reportable disease. It is not transmitted via horse-to-horse contact, but is easily spread by horseflies, deer flies, and other bloodsucking insects. And since it stays with a horse for life, infected horses must either be put down (which is mandatory if they show “strong clinical signs”) or permanently quarantined.
In Eastern Canada, a larger portion of the horse population travels to shows and events, and so having a Coggins Test (screening for EIA) is a matter of course.
“Management of the disease there is different than here in the West, primarily because of the type of horses. There’s also a history of monitoring for it in the East,” said Dr. Greg Evans of the Moore Equine Veterinary Centre near Calgary and a member of the health and welfare committee for Equine Canada.
Most competitions, and even some stables, in Eastern Canada require testing. In the West, competitive horses are usually tested, but many ranch and pleasure horses are not. As well, pastured horses might encounter some of the same deer fly and horsefly populations as the feral horses, which many consider to be a reservoir for the virus.
But testing and monitoring requirements here may be poised to change.
The CFIA is currently reviewing those and has sent out a proposed risk management and control strategy for stakeholder comment. It is also working with the Western College of Veterinary Medicine on a retrospective study, looking at EIA testing and cases in Canada between 2009 and 2012. The agency says the project will look at surveillance and outbreak patterns, as well as possible risk factors.
The two initiatives will influence “future policy decisions specifically related to surveillance and options for control,” a CFIA spokesperson said in an emailed statement.
“The big question is, who would pay for increased surveillance and testing?” said retired Ponoka veterinarian Dr. Gary Harbin, who saw just one case in 43 years of practice (a draft horse that displayed no symptoms).
A Coggins Test typically costs $70 to $100, so there is a significant economic consideration.
Evans has not seen a single case in his 13-year career, but said some view Western Canada as the untamed frontier for EIA, with no real desire to deal with it.
“We have to protect international trade and travel,” said Evans. “If EIA gets more frequent, there could be push-back from our partners. It’s something we have to be cognizant of as an industry because we don’t want to eliminate the ability of our horses to travel.”
The goal should be to eradicate the virus, he said.
“It’s been done in other places. But it would require a significant increase in the number of horses under surveillance, and change in the way we do surveillance.”
Getting an overview of the presence of the virus in Western Canada’s population would mean testing large herds of horses on pasture, at auction markets, and possibly in the wild. The latter would be a daunting, and controversial, effort since the wild horses would have to be rounded up and then kept confined while the blood tests are being processed.
But the horse industry needs to be proactive, said Evans.
“It behooves us to examine what we could or should do better,” he said. “It’s better for everybody if we can eliminate the stigma.”
What that might involve isn’t known at this point as the CFIA’s proposed risk management and control strategy hasn’t been made public.
But some jurisdictions have taken aggressive measures. In some areas of the U.S., every horse sold must have a clean Coggins Test. Other areas impose regional travel restrictions. Another possibility is mandatory testing for any rescued, rehomed wild horses — something the Alberta Veterinary Medical Association has twice recommended to authorities.
And it’s likely most or all of the cost of any additional testing will fall on horse owners.
“In Ontario, testing is considered part of the yearly health maintenance,” said Evans. “It’s considered part of the owner’s health budget, and is entrenched in the horse culture there.”
Depending on the results of the CFIA’s program review and recommendations on EIA control, that might not be a choice.Dr. Greg Evans Photo: Thinkstock“People shouldn’t panic, because it’s a low-prevalence problem.”Dr. Renaud Leguillette