As if Canadians weren't battered enough by microbial menaces after dealing with SARS, along comes mad cow. A routine inspection of a slaughtered Black Angus in Alberta revealed it had been infected with the disease. Inspectors have quarantined 16 sites across Canada as they explore how the cow got sick. Canada's beef industry is reeling but it could get worse. Officials are checking whether cows on at least three farms in British Columbia may have had access to chicken feed that contained protein from the contaminated cow, thus spreading the disease more widely than thought.