For months, the Canadian hog industry had been hoping it could keep the porcine epidemic diarrhea virus out of the country.

But no luck there. With its arrival here — at 11 Ontario locations so far and more expected — a $3-billion Canadian industry that has been getting its financial house in order now finds itself facing a new challenge.

In the U.S., where the virus was first detected last spring, its toll had been mounting. Estimates suggest that up to five million pigs have died and that PED has spread to 23 states.

Here's a closer look at the deadly pig virus —​ which doesn't affect humans —​ and some of the issues surrounding it.

Hard on piglets

PED, which belongs to the coronavirus family, infects the cells lining the small intestine of a pig. For piglets, this is very bad news.

Their bodies haven't developed the reserves needed to fight off the disease and absorb nutrients, so they succumb to diarrhea and death.

"An adult pig does become infected and they do get sick, but it's very mild, and then the adult pigs have the ability to recover," says Dr. Terri O'Sullivan, president of the Ontario Association of Swine Veterinarians. "It's an age factor, and the piglets are just not mature enough."

Mortality rates can be up to 100 per cent for piglets less than a week old.

Canadian hog industry

​Number of hogs on farms, 2013: 12.9 million, down from 14.7 million in 2003

Hogs as a percentage of hogs, cattle and sheep on farms, 2013: 46.8, up from 46.5 in 2003

Value of farm cash receipts from hogs, 2012: $3.8 billion, up from $3.2 billion in 2002

Hogs as a percentage of farm cash receipts 2012: 10.6, up from 9 in 2002

Source: Statistics Canada

Once a piglet hits three or four weeks of age, it can survive, says Dr. Lisa Becton, director of swine health information for the U.S. National Pork Board in Des Moines, Iowa. 

Any animal that is exposed and survives builds immunity, which means that once a farmer can get natural immunity into the herd, there is a much better chance of managing the disease.

PED virus is passed by what vets and others call the oral-fecal route: it is shed in the manure of infected animals, and picked up through any contact another pig's snout or mouth might have with that manure.

The virus also thrives in cold weather, and can linger after manure is removed from a surface.

The origin of PED is unclear. A much milder strain has been in Europe since the 1970s, and "does not pose much of a threat" there, O'Sullivan says. Research on the virus spreading in the U.S. has found genetic similarities with a virus identified in China in 2012.

Pork is safe to eat — and won't disappear from stores

For those who love their bacon, there is no need to fear the pork supply will evaporate. Pork remains safe to eat.

"It's not a human health concern," says Sullivan. Moreover, the disease is not likely to have an impact at the grocery counter.

Food American Table Pork Chops

Pork chop lovers need not fear -- the spread of the PED virus has no effect on human health and pork remains safe. (Matthew Mead/Associated Press)

"You don't have to worry about product shortages," says Stewart Skinner, who runs a 350-sow farrow-to-finish farm with his parents near the southwestern Ontario town of Listowel. "We live in a highly integrated North American market and pork is traded both ways across the border."

Even though up to five million pigs have been lost to PED in the U.S. since May, that is only a small portion of the 110 million pigs that are likely to be slaughtered in the U.S. this year.

What's more, any loss because of PED will likely counter a previously expected increase in production, says Steve Meyer, president of Paragon Economics in Des Moines

"First you're going to see wholesale and hog prices go up and retail prices usually don't adjust until several months afterwards," says Meyer. "That's the shock absorber in the system.

"I don't know if we'll see much higher retail prices this summer, but I do know we won't see lower retail prices."

Overall income could rise

Government response

Federal and provincial governments have been stepping up efforts to fight PED.

Late last week, the federal government said it would allow a vaccine undergoing preliminary testing in the U.S. to be imported to Canada and be used as a precautionary measure.

The Ontario government has pledged $2 million to help farmers boost bio-security measures to stop the spread of the virus, which can be easily transmitted by everything from the dirty tread of a workboot to an infected pig loading chute or transport truck.

Perhaps counter-intuitively, as devastating as PED might be for an individual farmer — Skinner estimates it could cost his operation $150,000 to $200,000 should he have a breakout — the overall income for unaffected pig farmers could increase as a result of PED.

As Meyer points out, demand for pork and hogs is inelastic, and a one per cent reduction in supply would produce more than a one per cent increase in price.

"When something like this happens, it's not good for the farms involved for sure," says Meyer, "but you do end up with a higher price out of it and that price is enough to offset the loss of quantity in the revenue calculation."

Canadian farmers are watching the U.S. situation closely, not just to monitor the spread of the disease, but because they are price takers.  

"The price we receive for pigs here in Ontario is based off the U.S. markets," Skinner said in an email, noting PED has already caused a bump in hog futures.

Not like cows

When the cattle industry was hit with BSE in 2003, trade embargoes were immediately slapped against Canada by the U.S and several other countries.

With PED, there have been no trade implications.

"The Canadian hog industry exports over 60 per cent of the pork we raise, so loss of trade access would be devastating," says Skinner.

Italy

Piglets rooting around in the hay as part of a political protest in Rome in December face no real threat from the PED virus -- a mild strain of it has been circulating since the 1970s. (Andrew Medichini/Associated Press)

Sylvain Charlebois, a food policy distribution expert at the University of Guelph, says he's been quite impressed with how the Americans have responded so far to the PED outbreak in Canada.

"Sometimes countries get zealous and very protective about these kinds of outbreaks, and they want to make sure they protect their own, but in this case, the Americans have been quite helpful."

Becton has had numerous conversations with representatives of the Canadian Swine Health Board, Ontario pork producers and veterinarians in Canada.

"I know both countries have been working very closely together for this disease," she said. "Even though we have a regional boundary and border, our diseases don't know borders and it's very critical for us to continue to work together."