Swine producers across Canada will learn over the next few months whether the measures taken so far are strong enough to contain and perhaps eliminate porcine epidemic virus.
Since the first Canadian site was confirmed positive late in January, as of press time, the virus has hit 63 farms in Southwestern Ontario, four in Manitoba and one each in Quebec and Prince Edward Island.
By late September, the virus had not yet emerged on any farms west of Manitoba, and the rate of infection had dropped off dramatically in Ontario, where only four new cases were found between April 30 and July 23.
There has been only a few more cases found in Canada since then, most recently confirmed at a farm in Manitoba on Sept. 24. The drop-off raises hope that the spread of the virus can be checked and that it can eventually be eliminated entirely.
However, the potential for new infections is rising as outside temperatures cool, says Mike Degroot, technical veterinarian for Ontario Pork.
PED virus survives longer outside of a pig when temperatures drop, says Degroot.
“With those factors in place, it will be a bit more difficult to clean things up in cold weather along with the fact that the virus survives better.
“The cooler weather now will be a time that determines it. We’ll find out here over the winter if we’re able to contain the virus during the winter months as well.”
While Ontario’s struggle with the disease has been a great source of information for producers on the Prairies, Degroot says the team in Ontario is grateful for what they have learned from outbreaks in the United States.
“There were some lessons learned in the U.S. that we were able to pick up on and have a heads-up that the virus was close by. A little bit of learning from each other and what people were going through just helps going forward.”
Contaminated feed was the likely source of the first 20 or so infections in Ontario, says Degroot. Those that followed were most likely related to transportation issues, he says.
Although some farms and commercial washes have beefed up their truck washing facilities, there is still not enough capacity to thoroughly wash and disinfect all of the trucks that are moving pigs within the region.
The emphasis, therefore, has been focused on trucks that are at a higher risk, including units crossing the U.S. border.
“All transport trailers going to the U.S. and back are either washed or dedicated trailers, not the trailers that are used elsewhere in the province. A lot of the trailers that go to sow farms are washed, or producers are using their own transport.”
Degroot says there has been considerable effort in segregating, dedicating and sequencing trailers to keep them from becoming a mode of transport for the virus.
Darcy Fitzgerald, executive director for Alberta Pork, says trucks and loading facilities have been the focus of biosecurity measures aimed at keeping PED disease out of the barns in his province.
“One thing we are looking at is, what is the protocol for trucks crossing borders? What is considered a good truck wash? We are trying to work with the industry on that, and across Western Canada and with the other provinces as well,” said Fitzgerald.
“I don’t think anybody was really prepared for this kind of washing. It was more like, let’s get the dirt off, that kind of thing, whereas now we are looking at hygiene and adding in some disinfection and other processes.”
Working together, Alberta Pork and Alberta Agriculture’s Growing Forward program have made a variety of tools available to farmers, including a self-assessment package that helps them analyze the biosecurity measures in place on their farms and figure out the best course of action to improve them.
“Since January of 2014, when it really hit home, like it hit Ontario and we could really see what was going on, I think producers really took an overwhelming new step to implement biosecurity protocols,” said Fitzgerald.
“A lot of that really was looking at the truck wash side of things: How do I wash the trailer, or how does it get washed before it actually arrives, and just the boots on the ground when you arrive at the farm.”
Degroot says work is underway to eliminate the disease from those farms that have been infected, but there are still some questions about the long term implications.
“(Cleaning up an infected site) is a matter of getting all the pigs on the site immune to the virus at the same time and not introducing any new pigs until the virus is eliminated,” he says.
“Those are the key steps, along with a lot of cleaning and disinfection going on. If you have buildings such as a nursery site or finisher site that are all-in and all-out, then once the pigs are removed, there is a lot of dedicated cleaning, washing and disinfecting to try and make sure the virus is off the premises before you bring new pigs in.”
The final step is to allow enough time for any remaining virus to die off before repopulating the site, says Degroot.
It’s still too early to tell whether regions that have been infected can eventually build sufficient immunity to keep the disease in check, he says. Individual pigs that survive the infection will stop shedding virus at some point, but there are still questions about how long it would take a group of pigs to stop shedding, says Degroot.
“There is some herd immunity buildup, and there also tends to be some more herd rebreaks that we’ve heard about from the U.S. than we’ve seen in the past.
“I think it’s still too early to tell, is this disease going to become commonplace in certain areas of North America, and if it does, how is the immunity going to respond?”
Ontario is currently focused on containing the spread of PED, which means limiting the number of positive sites and eliminating the virus from those sites, says Degroot.
“We’re hoping that, as we move toward the end of the year, we’re actually going to see less cases in Ontario than what we had at, let’s say March-April.”
Shipping protocols have been set up to ensure that slaughter pigs coming in from positive farms do not pass the virus past the loading docks that receive them.
Slaughter hogs shipped from positive farms are brought in to dedicated sites and processed at the end of the day or the end of the week. Those sites are then disinfected and dried before accepting more shipments, says Degroot.
“Overall, we’ve had good-news stories through the spring and summer in Ontario,” said Degroot.
“We’re hoping to continue to contain the virus, and if we’re able to contain it, we can move toward elimination.
There are roughly 2,000 farms in the affected area of Ontario, ranging in size from a few hundred to 3,000. The majority of farrow-to-finish farms would be in the range of 200 to 500 sows.
In Alberta, producers are encouraged to use the resources provided by Alberta Pork and Growing Forward to seek out and fill any gaps in their biosecurity protocols. Assessment tools are available online at albertapork.com and producers can also contact Charlotte Schipp, industry programs co-ordinator, for help with assessments and any grants that may be available to help cover costs of upgrading their systems.
Contact Schipp by e-mail at charlotte.schipp@albertapork.com or by calling 1-780-491-3528.
Common in areas of Asia, PED was unknown in North American until an outbreak began affecting U.S. swine herds in May of 2013. The disease spread rapidly throughout pork-producing regions of the country and has now been confirmed on 8,316 farms in 31 states.
While PED poses no threat to humans, it causes extreme vomiting and diarrhea in infected swine. The virus kills almost 100 per cent of nursing piglets that become infected. •
— By Brenda Kossowan