Porcine Epidemic Diarrhea virus (PEDv) is one of the most devastating diseases to confront the U.S. pork industry. Images of baby pigs that had succumbed to the disease left an indelible mark in producers’ minds. Veterinarians painfully – but openly – shared their experiences with the disease in an effort to help others know what to expect.
PEDv itself causes severe diarrhea, primarily in pigs less than 2-3 weeks of age and for the next 2 weeks of farrowing. Baby pigs had rapid onset of disease and a high percentage of these pigs died. Sows with PEDv experienced lack of appetite, diarrhea and vomiting, but death loss was lower. Wean-to-finish pigs showed similar clinical signs but fewer pigs died from the virus.
How Did It Get Here?
How the virus got into the United States is still a big question. It matches the PEDv strain common in China, which leads researchers to believe it originated there. Since a high percentage of feed supplements are produced in China and delivered to the United States, these materials were considered suspect at the time of the initial outbreaks. Dr. Paul Yeske, a veterinarian with the Swine Vet Center in St. Peter, Minn., spoke at the 2015 Iowa Swine Day on PEDv. He says feed totes used to ship bulk ingredients from China and other areas could be a potential source of the virus. These totes can be reused and could potentially create a biosecurity issue. He says a study is in progress on this potential disease source.
Neil Dierks, CEO of the National Pork Producers Council, said earlier this year, “PEDv is a very scary, very serious reminder that we live in a global world. We have to always be as diligent as possible with biosecurity as well as how to go forward to maintain our ability to export.”
Take Rapid Action
One of the problems in battling PEDv lies in its ability to spread infection quickly. Dr. Darin Madson, DVM, PhD, with the College of Veterinary Medicine at Iowa State University says, “It takes very few particles to cause infection. In essence, one to two virus particles is enough to infect a day-old piglet.”
Yeske says, “Although similar to TGE (transmissible gastroenteritis), PEDv is a different bug. It is more active in warm environments and is more difficult to control in a sow herd. The clinical picture is more severe, and there is apparently no cross-protection with TGE or Porcine Coronavirus. Biosecurity at all levels should be evaluated, with particular emphasis on transport to and from a processing facility and feed delivery.”
A laboratory diagnosis is needed for determining a site’s status and managing biosecurity or bioconfinement. That’s why rapid action is necessary. If PEDv is suspected, a site should be on immediate lock-down.
“The goal is containment of the disease and reduction of the potential spread to other sites,” Yeske says. “Also, anything (or anyone) that touched the farm in the previous 72 hours should be monitored.”
Decisions regarding animal flow also are important. Yeske says, “Are pigs being weaned to the right site? What age are the pigs already at the site? If the farm you’re moving these pigs to already has weaned pigs, do you want to bring PEDv to that site?”
In addition to pigs and buildings, transport equipment can’t be forgotten as a potential source of disease spread. Traditional means of disinfecting trailers and rooms still allow enough virus to remain and cause disease. Heating to 160 degrees Fahrenheit appears to provide enough heat to eliminate the risk of spreading PEDv.