A flock of sheep near Lashburn, Saskatchewan, was seized for slaughter because they could be infected with a nervous system disorder.

Officials removed 25 sheep from the farm Tuesday after a ewe from the flock tested positive for scrapie. The farm is by the Alberta-Saskatchewan border.

Found in sheep and goats, scrapie causes trembling, weight loss, scratching and death.

Owner Fred Davis says the sheep originated from a flock in Maidstone, Sask. He bought them at a sale in Lloydminster.

The Canadian Food Inspection Agency is now tracing all the other sheep from the infected flock.

There is no known danger to humans from scrapie, says Health Canada.

Known as a transmissible spongiform encephalopathy (TSE), scrapie is related to bovine spongiform encephalopathy (BSE), or mad cow disease.