A third case of mad cow disease has been discovered in Alberta although Canadian officials insist that no part of the animal had entered the human or animal food chains.

The concern, however, is that this cow was born after the new 1997 legislation passed in Canada to restrict the spread of mad cow disease through feed. Health authorities in Canada believe that the disease was most likely contracted through feed that was manufactured before the new rules took affect but eaten afterwards. They suspect that this cow contracted the disease early in its life.

Mad cow disease, or bovine spongiform encephalopathy (BSE) causes cows to get sick and die. Humans can contract a form of the disease if they ingest a cow contaminated by BSE. In humans, mad cow is almost always fatal.

The United States recently announced it would resume importing beef from Canada in 2005. No imports from Canada had been permitted since May of 2003. There was no word from the Agriculture Department if the recent finding would have any effect on that decision.