New findings of bluetongue in cattle in Canada — outside the one area of the country where the virus previously gained a toehold — have trading partners shutting their ports to Canadian livestock genetics and animals.
Three cattle from one southwestern Ontario farm have now tested positive for bluetongue serotype 13 — one animal on Aug. 7, from surveillance samples taken at an abattoir, and two more from follow-up testing at the farm, on Sept. 2.
The positive animal at the abattoir showed no clinical signs of the disease before slaughter, the provincial agriculture ministry said in a notice Friday.
Neither of the other two animals had ever left the farm, nor were there any animals on the farm imported from the U.S., the province said.
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.
The new findings aren’t going to affect Canadian trade in live cattle or meat with the U.S., where bluetongue is already endemic.
But 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, said in a release Thursday.
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.”
OSMA also urged producers to watch for signs and symptoms of bluetongue in their flocks, such as high fevers (over 41 C); lameness; swollen and inflamed muzzles, feet, ears and other body parts; and swollen and/or eroded tongues and gums. In an epidemic situation, OSMA said, death losses in an infected flock can run up to 30 per cent.
Bluetongue, which doesn’t spread by ordinary contact between livestock, usually only turns up in Canada in late summer and early fall, since conditions must be warm for the virus to multiply in the host midge — and a first hard frost shuts down any midge activity.
In Canada, host midges have until now been seen only in the Okanagan, and in southern parts of Manitoba, Saskatchewan and Alberta where the pest has “limited ability” to survive and spread bluetongue.
Cancelled certificates
Canada’s status as bluetongue-free by World Organization for Animal Health (OIE) standards has relied on no new cases of U.S.-endemic serotypes outside the Okanagan, where nearly all of Canada’s bluetongue cases in the past 30 years have been found.
The southwestern Ontario cases also mark the first time the virus has been found in livestock on a birth farm outside the Okanagan.
A memo circulating Saturday from the Canadian Beef Breeds Council reports several countries have already cancelled their export certificates that had allowed Canadian ruminants and ruminant genetics.
Resulting bans so far, the CBBC said, include imports of live Canadian cattle to the European Community, the Philippines, Ukraine, Colombia, Algeria, Azerbaijan, Macedonia, Moldova, Morocco, Serbia, Switzerland and Tunisia; cattle semen to the European Community, China, Brazil, Chile, Peru, Australia, New Zealand, Algeria, Burkina Faso, Iran, Jordan, Lebanon, Norway, Sri Lanka, Switzerland, Tunisia, Vanuatu and Vietnam; and cattle embryos to China, Japan and Iran.
Countries now blocking imports of both Canadian sheep and goats include the European Community, Russia, Ukraine, Chile, Guyana, Trinidad and Tobago, Switzerland, St-Vincent, Serbia, Macedonia, Iran, Lebanon (for slaughter) and the Azores. Barbados and Swaziland will now also block live Canadian goats, while the European Community will also block live Canadian camelids, such as alpacas and llamas.
Countries blocking sheep and goat embryos now include the European Community, Iran, Chile, Jamaica and St-Vincent. China, Colombia, Taiwan and Israel will also block Canadian hides, and Vietnam will block porcine dried blood.
Source : AlbertaWheat