Canada's Food Inspection Agency - which confirmed the results Sunday - had suspected last week the cow was infected with the disease based on preliminary testing.
The agency said at the time that human food and animal feed supplies were not affected.
The confirmation comes just days after the United States announced plans to reopen its border in March to nearly all Canadian beef and live cattle. U.S. officials banned the import of Canadian cattle in May, 2003, after Canada found its first case of the disease.
Mad cow disease attacks the central nervous system of cattle and can be harmful to humans if tainted meat is consumed.
Some information provided by AP, AFP and Reuters.