Pig virus scare turns out to be minor disease

Thursday, November 5, 2015

by SUSAN MANN

A virus causing vesicular lesions on pigs’ snouts and feet, similar to foot-and-mouth disease, has made its way into Ontario.

In late October, three Canadian pigs with vesicular lesions sent for slaughter in the United States were found to be positive for Seneca Valley virus at an American slaughter facility. According to a Canadian Pork Council fact sheet, the United States Department of Agriculture informed the Canadian Food Inspection Agency the Canadian pigs were confirmed to have Seneca Valley virus.

The CFIA’s investigation traced the pigs to three farms in Ontario and Manitoba. The farms and two assembly yards were checked out. Seneca Valley virus was detected only in samples taken from one Ontario assembly yard, the fact sheet says.

As part of its investigation, CFIA ruled out vesicular foreign animal disease, such as foot-and-mouth disease.

Seneca Valley virus is not a human health or food safety risk. It also isn’t considered to be a production-limiting disease. The virus causes increased mortality in pigs less than seven days old and possibly diarrhea, the fact sheet says.

For breeder, finisher and grower pigs, the virus causes loss of appetite, fever, lethargy, blisters on the snout, mouth, feet or teats, lesions on the feet surrounding the coronary bands, lameness (ranging from slight discomfort to refusal to move) and loose foot pads that may lead to loss of hooves.

Mary Jane Quinn, Ontario Pork communications and consumer marketing manager, says Seneca Valley virus is not a reportable disease but farmers should contact their veterinarians if they suspect “they might have something that resembles Seneca Valley virus because you don’t want to be shipping the pigs.”

Officials have to first rule out that the virus isn’t a vesicular foreign animal disease, such as foot-and-mouth, before the pigs can be shipped to a slaughter plant, she says.

Veterinarian Mike DeGroot, Ontario Pork’s biosecurity coordinator, says Seneca Valley virus can, in some cases, cause the vesicular lesions around pigs’ snouts and feet. “It’s those vesicular lesions that show up most prominently with foot-and-mouth disease.”

Foot-and-mouth disease would have big impacts on the industry, whereas Seneca Valley virus is “a very mild disease,” he says. Foot-and-mouth is a reportable disease. The last case in Canada occurred in the 1950s in Saskatchewan.

DeGroot says the two diseases can look the same and “you can’t tell the difference in an individual animal without doing the testing. Seeing lesions on pigs “needs to get reported to CFIA to rule out foot-and-mouth disease.”

It’s unclear how Seneca Valley virus is transmitted, he notes. It’s from the same family of viruses that cause foot-and-mouth disease.

The standard biosecurity procedures developed over the years for farmers will help reduce transmission of any disease and Seneca Valley virus probably falls under that too, he says. BF