Investigators probing a third case of BSE reported that there was no trace of the brain-wasting disease in any of the other animals likely to have been exposed to the infected cow, according to a Dow Jones report.

The Canadian Food Inspection Agency said Friday that nine animals born on the same farm within a year of the infected Alberta dairy cow have tested negative for mad cow disease, or bovine spongiform encephalopathy.

"All cattle exhibiting symptoms consistent with BSE have been, and continue to be, diverted from the food system," the agency said. "In regards to birth cohort risk, international research shows that finding more than one case of BSE in a birth cohort is rare."

The dairy cow was one of two diagnosed in Canada since the Bush administration said it would lift a ban on Canadian cattle. An earlier case in 2003 prompted the ban.

Agriculture Minister Andy Mitchell has previously suggested the Alberta cow was infected by feed which had been left over after the 1997 ban was implemented.