A Holstein bull slaughtered in Ibaraki Prefecture last month was confirmed Monday to have been infected with mad cow disease.
The 23-month-old bull is the eighth case of the brain-wasting illness found in Japan and is believed to be the world's youngest carrier of the disease also known as bovine spongiform encephalopathy, according to the Health, Labor and Welfare Ministry.
The bull was brought to the slaughterhouse Sept. 29; two separate sets of tests carried out by Ibaraki health officials and the National Institute of Infectious Diseases raised concerns about possible mad cow contamination.