A fifth case of a deadly and highly contagious pig virus has been confirmed in Ontario.

The provincial agriculture ministry says a pig from a farm in Simcoe County north of Toronto tested positive for porcine epidemic diarrhea on Saturday morning.

It's the third hog to test positive this week in the outbreak, which saw its first confirmed case on Jan. 22.

Ministry spokeswoman Susan Murray says more pigs are expected to test positive for the virus - which has killed millions of piglets in the U.S.

The Canadian Food Inspection Agency announced this week it will issue permits allowing veterinarians to import a vaccine for the virus as a precautionary measure.

Officials stress that there is no risk to human health or food safety.