Will Canada Check in with #7?

According to CIDRAP, Canadian officials have announced that they are waiting for test results to confirm whether or not a seventh cow has been found to be carrying BSE. Samples from an Alberta cow are being tested.

For those keeping track, a 15-year-old cow from Manitoba was just discovered to be carrying BSE just six days ago.

So if Canada has found six BSE-positive cows with a possible seventh yet to be determined, why have we only found three American cows with BSE so far? Don't even get me started on the amount of cows Japan has found so far...

A quick search of the Canadian Food Inspection Agency's page says they found three BSE-positve cows in a high-risk population of 60,000. (Obviously, that stat is as of 3-4 cows ago...)

Anyone know how many cows Canadians slaughter for food per year versus how many are tested for BSE? We eat about 75 million cows per year here in the U.S., (last stat I remember seeing on the subject, that number may be higher or lower now). How many are we testing? How many BSE-positve cows are getting through to U.S. dinner tables?