Final test results have confirmed a diagnosis of bovine spongiform encephalopathy in a cow from Manitoba, the Canadian Food Inspection Agency said Tuesday.

An agency investigation determined the owner of the animal, a mature, cross-bred beef cow, purchased it as part of a group in 1992.

That means the animal, which lived in the Interlake area, was at least 15 years old, so it was born well before 1997, when Canada imposed a ban on the type of feed associated with BSE.

Investigators are working to locate the animal's birth farm, which will help identify other herdmates that could have been exposed to the same feed.

However, agency officials said Tuesday the investigation might be "constrained" by the animal's advanced age and a lack of detailed records after such a long time.

A calf born to the animal in 2004 is being traced.

Last week, the province's chief veterinary officer, Dr. Wayne Lees, said the animal did not enter the human or animal food systems.

"It was a cow that would have been bred every year, and then the calves would have been sent for feedlot use down the road," he said Friday, adding there is almost no chance the cow could have passed the disease to its offspring.

The animal's owner had it euthanized and sent for inspection after it showed signs of BSE, including difficulty walking, Lees said.