Bluetongue disease is a non-contagious viral disease that affects ruminants, mainly sheep but occasionally, as in this case, cattle.
It was found in a single animal at the point of slaughter, the OIE said in a report, and then two further cattle were tested positive during on-farm testing. No clinical signs were observed in any of the three animals.
“This is the first occurrence of bluetongue serotype 13 in Canada, and the first occurrence of bluetongue outside the Okanagan Valley,” said Dr Martine Dubuc, OIE delegate for Canada, chief food safety officer and vice-president at the Canadian food inspection agency. “Because these animals have never left the farm of origin, we conclude that transmission of bluetongue virus has occurred in Ontario for the first time.”
Bluetongue virus serotype 13 is endemic to the US. The affected beef cattle farm is located in southwestern Ontario, within 100km from the border with the US.
In line with Canadian policy, no control measures are to be implemented and the incident is considered to be concluded.
Bluetongue is a viral disease affecting domestic and wild ruminants, including sheep, goats, cattle, bison, deer and elk. The disease is present in numerous countries and is currently spreading northward in Europe
The disease poses no threats to food safety or to human health, and its effects are mild or inapparent in most livestock, such as cattle and goats, but it can cause serious or fatal illness in sheep and wild ruminants such as deer.
However, bluetongue impacts trade; countries free of bluetongue restrict importation of live animals or animal products, including semen and embryos, from countries that may have bluetongue.
Although the disease primarily affects sheep, it also has great economic impact on the cattle industry because cattle can carry the virus post-infection and show no clinical signs.
Loss of bluetongue-free status in Canada means immediate suspension of export certificates for live animals, semen and embryos until certificates can be negotiated with trading partners. Trade of beef for human consumption will not be impacted.
'Present and real'
For Ontario’s sheep producers, the findings mean “the threat from bluetongue is now present and real”, as Dennis Fischer, chairman of the Ontario Sheep Marketing Agency (OSMA), said in a press release.
A virus transmitted mainly through biting midges, which can be blown by the wind over long distances, makes it difficult to put biosecurity measures in place to prevent bluetongue from turning up on sheep farms, he said.
“We are, however, encouraging producers to keep sheep away from wet and low-lying areas and, if possible, house sheep in barns at night when the midges are most active.”