A Hokkaido cow was confirmed Monday to be infected with mad cow disease, the fourth case in Japan since September, health ministry officials said.
A panel of experts appointed by the Health, Labor and Welfare Ministry made the final confirmation based on data gathered from a pathological examination, as well as from a Western Blot examination, a more elaborate screening test for the disease that is formally known as bovine spongiform encephalopathy, the officials said.
The health ministry earlier said the cow -- a 6-year-old female Holstein -- was born and raised at a dairy farm in Ombetsu, eastern Hokkaido.