The province's chief veterinary officer has confirmed there are now five farms in Manitoba where porcine epidemic diarrhea (PED) has been found.
While there is no clear link between these cases, Manitoba Agriculture wants the industry to be more vigilant.
"All pork producers must maintain strict on-farm biosecurity procedures to keep PED out of the barn," reads an information update posted on a government website.
"It is critical that the entire industry, including producers, transporters and suppliers work together to reduce transmission through good biosecurity practices."
PED is a virus that causes severe dehydration and diarrhea in pigs and has killed millions of piglets in the United States since May 2013.
The virus is not transmitted to people or other species of animals and is not a food safety risk. There is concern about how PED could affect the multibillion-dollar pork industry, including driving up consumer prices.
PED has also been found on farms in Ontario, Quebec and Prince Edward Island.
Manitoba Pork says investigators have found that some people aren't following basic biosecurity rules when they deliver hogs to slaughter facilities and to pens where live pigs are held before they are shipped to market.
These sites are considered to be at higher risk for the virus because of the number of animals that come into close contact with each other.
Mark Fynn, a spokesman for Manitoba Pork, said something as simple as a producer not wearing disposable covers on their boots or failing to wash manure out of their vehicle could spread the virus.
Fynn also said producers should ensure that anyone visiting their farm, such as service people, follow biosecurity safeguards as well.
"We have seen a few breaches in biosecurity practices that are kind of alarming," Fynn said Thursday. "We are seeing some stuff not being obeyed all of the time."
Fynn said it is in the best interest of producers to strictly follow the rules so they don't track the virus back to their own farms.
PED, which appears to thrive in colder weather, can wipe out every piglet in a barn.
Fynn said the hog sector is a $1.7 billion industry in Manitoba, supporting about 13,000 direct and indirect jobs.
Figures on how many pigs have died from the PED in Canada were not immediately available.
Fynn said Manitoba Pork will share its concerns about the need to follow strict biosecurity rules with pork producers from Alberta and other provinces on Friday.
— By John Cotter in Edmonton