Cull sows no longer stopped at U.S. border

Canada’s swine industry appears to have dodged what could have been an economic catastrophe with quick action on senecavirus A.

In August this year, 13 Ontario animals were identified with lesions on their snouts or hooves at a processing plant in the U.S., triggering a memo from the U.S. Food Safety and Inspection Service to increase vigilance at the Canada/U.S. border.

As a result, 10 loads of Canadian cull sows heading to the U.S. for processing were turned back between Sept. 13 and Sept. 26 when lesions were found on sows. Due to quick action and extensive testing in Ontario, however, no loads have been rejected due to lesion concerns since Sept. 26.

Senecavirus A causes scours and mortality in pre-weaned piglets and lesions on the snouts and the area around the hooves in sows that can cause lameness. Those symptoms are consistent with reportable foreign animal diseases, including the dreaded foot-and-mouth disease. It does not affect human health.

“Reportable diseases show around the nose, mouth and hooves,” veterinarian Martin Misener, chair of the Ontario Swine Health Advisory Board, told Swine Health Ontario’s Big Bug Day on Oct. 20. “This pesky thing does too.”

Senecavirus A was first found in the U.S. in 1988, but has been spreading and causing more problems since 2015. About 70 per cent of Brazilian sows are positive for the virus. It has previously been reported in Canada but hasn’t caused significant issues.

A similar situation to the 2016 border issue happened in 2015, when cull sows from Manitoba and Ontario were identified with vesicular (water blister) lesions at packing plants in the U.S.. A Canadian Food Inspection Agency (CFIA) investigation identified senecavirus A at an Ontario assembly yard. Misener said he doesn’t know why that didn’t trigger the problems at the border seen this year.

Misener, who spent two weeks working on the senecavirus A situation, said 98 per cent of the lesion concerns at the U.S. border were from trauma and about two per cent were from senecavirus A. None were from a foreign animal disease.

The Ontario industry has created a disease command centre under Swine Health Ontario that allows for quick and co-ordinated response with the involvement of the CFIA, the Ontario industry and OMAFRA.

Dr. Doug MacDougald, another veterinarian, said at Big Bug Day that the senecavirus situation shows the need for the command centre and demonstrates its positive impact. He also praised the three companies exporting cull sows for their co-operation.

Most Canadian cull sows are processed in the U.S., so any disruption of sow flow at the border means backup of sows to assembly yards, then to farms.

Animals that trigger foreign animal disease concerns will shut down Canadian processing plants until testing has shown that the symptoms are not a concern, which is why there’s so much concern with senecavirus and its symptoms that look like other diseases.

The Canadian industry has an advantage in that all cull sows go through three primary assembly yards. That means testing protocols can be established to screen the Canadian herd for foreign animal disease, said Misener.

This wouldn’t be an early-warning system, he said, but a system which would build confidence that the Canadian herd is free of foreign animal diseases.

“We need to stay very vigilant for any swine vesicular disease presentations,” he said. “This is everyone’s responsibility.”

— John Greig is a field editor for Glacier FarmMedia based at Ailsa Craig, Ont. Follow him at @jgreig on Twitter.