Ken, the Canadian cow, was in fact, a black angus. The thing I find a bit unusual is that the black angus and the holstien are not all that common in Alberta. We are not known for our dairies at all, we are beef country and Albertans lean more toward red angus than blacks. You'd think it would make them easier to track cause they do stand out like a sore thumb. The black originated in Saskatchewan, or at least that's what the government vets tell us and the folks that bred her have one of the most unusual operations I've ever heard of. They've been runnning black angus for 100 years, but the son who was running the operation currently, has had a completely closed herd for 25 years. It makes for a tight breeding program but they had brought in absolutely no cattle from the outside, not even bulls for new bloodlines. They grow all their own feed, have never bought any feed with the exception of protein blocks (nutralix and crystalix, the popular choices) but the area that they were living in, is a where chronic wasting was first found in deer farms and it seems to be quite concentrated in that area. We have very stringent regulations about releasing domestic deer into the wild but I've seen tagged deer roaming the countryside. I'm not saying that folks are getting tired of their livestock and releasing but I would suggest that anybody that has livestock knows they can liberate themselves once in a while and deer blend in a bit more than cattle, who are quickly recovered if they escape. The popular theory here has been that there is a strong chance that the disease has mutated and moved species, but again, that's just one more theory to add to all the others.
Sorry for being so long winded folks.