While the origin of recent porcine epidemic diarrhea outbreaks has not been identified, Manitoba’s chief veterinarian has determined the strain is not unique to Manitoba.
“What we do know is that all three barns have the same strain of PEDv and that the strain is not one that is unique to Manitoba, it’s been found in Ontario and the U.S. as well,” said Dr. Megan Bergman. “But at this point — with the exception of geographic location — we haven’t identified any common contact between these three barns, so we continue to review our epidemiological information to try to really further evaluate in more detail whether or not we can pinpoint a source of introduction.”
The three most recent cases of the disease appeared between May 26 and June 4, after nearly 16 months of being PEDv free. All the cases occurred within a five-kilometre radius, in the southeastern part of the province.
However, given the complexity of interactions between hog operations and the larger world — including other farms, trucks, processors, staff, visitors, feed suppliers and other considerations — it is conceivable the cause of these cases may never be pinpointed.
“It is very possible that we will never know exactly how this virus was introduced,” said Bergman.
Some in the hog industry had initially questioned if each barn was infected with the same virus given the varying level of symptoms, but the chief vet said that is to be expected.
“Age is actually the biggest factor in respect to the symptoms that we see in these pigs, the younger the piglet, the more significant the clinical signs are and even a difference of a few days in age can make a big difference in how hard they are hit by this virus,” said Bergman. “So we do think that is largely the cause of why we’ve seen a difference between the barns, and of course we had one finisher barn that was affected, and finisher animals are quite a bit older, so they are able to manage that virus quite a bit better than piglets.”
All three of the barns are currently at a different stage of the cleaning and disinfection process, which Bergman said could take a significant amount of time. She added that the possibility of further cases of PEDv can’t be ruled out either.
“We have such significant contact with the U.S. and of course the U.S. has a high virus load for PEDv, so I think we also need to prepare ourselves for the potential introduction of the virus and to be able to respond quickly,” she said.
But recent hot and dry weather could be good news for Manitoba hog producers.
“My hope is that with the recent sun and hot weather that we’ve been getting, is that any level of environmental contamination may be reduced because we’ve got some good weather and this virus does not like hot, dry weather,” Bergman said.