PEORIA, Ill. – “Why Me? Now What?”

That was the title of Dr. Bill Hollis’s presentation on PEDV, porcine epidemic diarrhea virus, but it echoed what producers in 25 U.S. states and, as of March 3, 24 sites in Canada, have been asking themselves.

“I did pick the title because that’s somewhat how we have reacted to this virus,” Hollis told an audience at the Illinois Pork Expo.

He said the virus was a factor, but didn’t seem to spread rapidly until the temperatures turned colder.

“We had a lot of folks who avoided it entirely all summer, all fall and then from Christmas to New Year’s, we had clients who just lit up with the virus. So we’ve seen a great deal of activity,” he said.

Hollis said that PEDV has been in Europe and Asia for years.

“This virus was around in the 1980s in Europe and has become somewhat quiet in Europe, similar to how we would talk about rotavirus diarrhea,” he said.

Hollis is a swine veterinarian with Carthage Veterinary Services, based in Carthage. He said the strain of virus identified in the U.S. is different from the European strain, as are the methods needed to control it.

“We know we can see some late lactational diarrhea. We know we can create a self-limiting environment where the virus doesn’t go on after pigs have been weaned. That is not the experience they have had in Asia, and unfortunately the virus that we have identified here in the U.S. is 99 percent similar to the viruses they have circulating in Asia,” he said.

First Appearance

Hollis said the first states to identify PEDV, which is very similar in appearance to TGE, or transmissible gastro enteritis, were Indiana, Colorado and Oklahoma.

“What we do know is somewhere around that late May/early April time period, in some herds in Indiana, Colorado and Oklahoma, it all blew up at the same time. We saw a great deal of activity in those herds and in those systems where it was first identified,” he said.

Hollis said the virus now has moved throughout the Midwest. It is particularly lethal to young pigs under 10 days old, but can infect sows, weaned pigs and finishing pigs, although it is not as deadly among those populations.

“It’s worked its way throughout the Midwest. This virus has continued to move. As we move pigs, we move the virus so there’s been virus moved throughout west-central Illinois, where our practice is located and all throughout the state of Iowa, where many of our clients are feeding their pigs,” Hollis said.

He said that while other viruses can cause watery diarrhea, the rapidity with which PEDV moves through a barn is one of its calling cards.

“It’s not one pig with watery diarrhea or even one litter. The farms that have had it exposed in farrowing, it goes from 20 percent of the litters at 9 a.m., 50 percent of the litters at noon and by tomorrow, 100 percent of the farrowing house is infected, so it’s very rapid,” he said.

Hollis said that the industry is working with associations, including the National Pork Board, the National Pork Producers Council, the American Association of Swine Veterinarians and others, to learn more about the disease and particularly how it moves.

“What we don’t know is where we keep bringing it to us and how is the best method to stop activity. Those are the things we’re trying to chase,” he said.

Devastating Disease

Hollis said when producers see a healthy litter of pigs that quickly shrink up and die, it can be frustrating and emotionally draining.

“If you have litters born next week, those pigs will be born beautiful. They will come out of the sow just fine. They look beautiful for two or three days until they’re exposed to this virus, then they shrink up, become starvers and start to die off. That’s the ‘why me?’ part,” he said.

One of the biggest questions that the industry is wrestling with is how and why the disease spreads.

“If it’s within a production system that uses the same feed mill, the same truck wash, it tends to move pretty rapidly through those systems. I have some clients who have a very low level of PED exposure. Of 70 sow herds, only five or six sow herds broke. I have other clients where it’s been half their production system in a matter of weeks. I would say both of those systems are using the same level of clean, separate trucks, shower in/shower out facilities. There are things we’re doing that we have figured out yet that are moving this virus,” Hollis said.

Even as the industry struggles to find answers about PEDV, Hollis said there are resources and information available about the virus and how to take measures to identify and control its spread.

“We know that it does not affect people. We know it does not create food safety risks. We know we can work through this,” he said.