While the porcine epidemic diarrhea virus (PED) poses no food safety risk or danger to humans, it has driven pork prices up south of the border.
The state with the largest outbreak of the virus is Iowa, which is also one of the top five states Ontario pork farmers export to.
Contamination occurs when feces infected with the virus get on the trucks and boots of drivers returning to Ontario farms.
Geri Kamenz raises breeding stock near Spencerville, Ont., and ships about 1,000 animals a month to Quebec. He said he worries about coming into contact with the virus at truck stops.
No treatment for the virus
"We've been able to make guarantees on health status to all of our customers, and if I lose the ability to make guarantees that I'm able to deliver healthy animals then my sales are going to dry up overnight."
There is no treatment for the virus. Kamenz said extra vigilance cleaning and disinfecting trailers from the U.S. is vital.
Dr. Marty Meisner is a veterinarian working with Ontario Pork, which represents pork producers. He said the virus thrives in cold weather and can live in snow banks near barns.
"Control and elimination will be extraordinarily difficult ... This virus does survive for significant times in the environment, and so cleanup of farms is very difficult and in fact in cold weather may be impossible," Meisner said.
Vaccines developed in Europe and China have so far been ineffective. Outbreaks can recur on farms because while larger pigs can become immune to it, the virus kills 100 per cent of the piglets it infects and new piglets are always being born.
So far, there have been no suspected or confirmed cases of the virus in Canada.