The first case of porcine epidemic diarrhea, a virus that’s killed over a million piglets in the U.S., has been confirmed in Middlesex County by the Ontario Ministry of Agriculture and Food.

While PED is highly contagious among pigs, it poses no food safety threat or a danger to humans.

“Pigs start to have diarrhea and they dehydrate very quickly and they will die within a day or two," said Robert Friendship, professor at the Ontario Veterinary College at the University of Guelph.

"That will spread throughout all the sows with piglets. Most of the piglets will die," he said.

The farm where the case was confirmed is not under quarantine, said Dr. Greg Douglas, Ontario's chief veterinarian.

"We have no concerns from my office that any products [or] animals are leaving the premises and causing any concern or threat to the Ontario pork industry,” Douglas said.

Ontario pork farmers have been bracing themselves for the spread since last spring, when PED began ravaging pig populations south of the border, driving up pork prices by 25 per cent.

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.

"It’s a highly contagious virus that in this very cold weather will survive in trucks and on boots and on clothing and equipment so it would be very easy to move from one farm to another,” said Friendship.

Vaccines developed to combat the virus in Europe and China have so far been ineffective.

While larger pigs can become immune to PED, the virus kills close to 100 per cent of the piglets it infects.