A cow suspected of having mad cow disease has been found in Shiroi, Chiba Prefecture, east of Tokyo, the Chiba prefecture government said on September 10.
According to the Ministry of Health, Labour and Welfare, it is the first suspected case of the disease in Japan.
The cow, a 5-year-old female Holstein dairy cow that a dairy farmer had been breeding, has been destroyed, according to the Japanese Ministry of Agriculture, Forestry and Fisheries.
Milk from the cow suspected of having the disease "'has already been distributed, but there is no effect to the human body,'" the prefecture government said. It also said that milk from the roughly 50 other dairy cows bred by the farmer would continue to be distributed.
The Japanese National Institute of Animal Health under the agriculture ministry in Tsukuba, Ibaraki Prefecture, apparently discovered that the cow might have the disease after it was put down. According to government officials from the ministry and the prefecture, they have set up headquarters to deal with the issue.
Mad cow disease, or bovine spongiform encephalopathy (BSE), was first confirmed in Britain in 1986. The disease is thought to cause the variant Creutzfeldt-Jakob disease (vCJD), the fatal human equivalent of BSE.
Cows infected with the disease usually die in two weeks to six months after developing symptoms, such as walking abnormalities, and the incubation period is about two years.
In a report compiled earlier this year, the European Union (EU) said there is possibility that mad cow disease might be found in Japan, but the Japanese agriculture ministry had then denied the report saying there is "a high level of safety in Japan."