While federal officials think they may have snuffed out one scrapie outbreak in Manitoba, they suspect they might have found an unrelated infection in another sheep flock.
“They’re at the end,” said Canadian Food Inspection Agency veterinarian Blaine Thompson about three recently exterminated flocks.
“They’re essentially dead ends.”
When scrapie appeared last year in a Manitoba flock, the CFIA traced the animals sold from that herd to other herds, and killed and analyzed them.
Of the seven flocks that imported sheep from the infected herd, three herds were found to have brought in infected animals.
Read Also
Stock dogs show off herding skills at Ag in Motion
Stock dogs draw a crowd at Ag in Motion. Border collies and other herding breeds are well known for the work they do on the farm.
Those three herds have been exterminated, and Thompson said he thinks that will end that particular outbreak because no ewes were sold from the three flocks.
A couple of rams were sold, but Thompson said males are not known to transmit the disease. These animals, however, will be carefully watched.
Thompson said an unrelated flock is now being examined because it might be infected with scrapie from another source.
There is no proof yet that the new flock is infected with scrapie, but the animals are showing some signs that make officials suspicious.
Scrapie is a transmissible spongiform encephalopathy, putting it in the same family as mad cow disease, chronic wasting disease in elk and deer, and Creuzfeldt-Jakob disease in humans.
Scrapie has been found in sheep in Europe for hundreds of years and has never been shown to infect other animals or humans.
All transmissible spongiform encephalopathies have long incubation periods, which means they can be inside an animal for years before appearing.
The diseases are hard to eradicate because there is no live test for them.
Animals and people must be dead before brains can be analyzed.
Thompson said the CFIA is used to seeing sporadic scrapie outbreaks.
“It’s quite an insidious disease.”
A Saskatchewan flock was found infected in 1999, but in the past two years there have been no cases in Saskatchewan, Alberta or British Columbia.
Eric Thornhill, president of the Manitoba Sheep Association, said producers hope culling the flocks will at least temporarily end the threat of scrapie in the province.
“We’re not satisfied with any scrapie, but the numbers are not really making us believe there’s a problem.”
He said producers would like to be able to test live animals so they know their herds are disease free.
“Until we get a live test, we’re going to struggle to eradicate it.”
