Pork industry leaders are warning producers to be on the lookout for a new virus that has been showing up in hogs in the midwestern U.S. and Canada in recent months.
Producers are advised to contact their veterinarians immediately and not move hogs if they detect blisters around their mouth, hoof, or nose.
Seneca Valley virus has has been sporadically identified in the U.S. since 1988, and was identified in Canada this year, a notice from Manitoba Pork to producers says. “Very little is known about the disease, how it spreads, how to prevent and/or control it, although direct animal contact and transportation vehicles are the most likely risk pathways.”
“Seneca Valley virus is a concern because you can’t distinguish it from the really scary reportable foreign animal diseases such as foot-and-mouth, without doing lab testing,” provincial veterinary epidemiologist Julia Keenliside said during Alberta Pork’s monthly pork town hall.
“Just by looking at the animal, you can’t tell what virus caused those blisters. If you see blisters, call your vet right away and get it checked out.”
Dr. Megan Bergman, Manitoba’s chief veterinary officer, said in an email her office has been working with industry, private veterinarians and the Canadian Food Inspection Agency to monitor the situation.
“Manitoba’s animal health lab (Veterinary Diagnostic Services) plans on implementing a diagnostic test when it becomes available. MAFRD is also working with industry to address implications if a positive case is found in Manitoba,” she said.
Detected at plant
In October 2015, two pigs from Manitoba, upon arrival at a U.S. slaughter facility, presented with symptoms and subsequently tested positive for Seneca Valley virus. However, followup testing of all source herds in Manitoba were found to be negative. No cases have been identified in pigs at any farm in Manitoba, she said.
About 70 premises in the U.S. were affected by the virus in 2015. Although it is not reportable, it does not seem to be spreading rapidly. The disease, which affects pigs, cows and mice, has been found here in the past.
“We want to send out the word to producers and people in the industry, especially those who transport pigs, to be on the lookout for blisters because it can be a very serious issue if we do have a serious animal disease,” said Keenliside. “It’s really important that we get everything looked at by a veterinarian, tested by CFIA and confirmed that it is not a foreign animal disease and that it is in fact Seneca Valley.”
Although not as severe as porcine epidemic diarrhea, the virus can cause increased mortality in piglets under seven days of age. The blisters only appear for a day or so, before rupturing. This causes sores near a pig’s nose and mouth or on their tongue. Sows and gilts may develop a fever and be off feed.
In growing or slaughter pigs, the animals will develop lameness because of painful blisters where the hoof attaches to the foot, so producers should watch out for acute, sudden lameness in a whole group of pigs.
“The good news is that it does seem to resolve very quickly and there’s not a lot of mortality,” said Keenliside.
Do not move
Pigs with blisters should not be moved and should not be taken to slaughter. Other reportable diseases that cause blisters in swine are swine vesicular disease, vesicular stomatitis and swine vesicular exanthema.
Foot-and-mouth is currently not in North America but if there was a case, it would cause an immediate border closure and a cessation of trade.
“It would be quite a disaster for our pig industry, and possibly other industries such as the cattle industry,” said Keenliside.
It is not known how the virus is transmitted. To see a slide show about the disease and what it looks like, go to www.nationalhogfarmer.com and search for ‘seneca facts.’
There is also a fact sheet courtesy of Manitoba Pork posted here.