Health Ministry officials said Monday they have found a fourth case of mad cow disease in Japan. Officials said they had confirmed that a 6-year-old Holstein dairy cow on a farm in Hokkaido had tested positive for bovine spongiform encephalopathy. Three previous cases of the livestock disease were found in Japan from September through November 2001. Officials tried to downplay the latest finding of a tainted cow by saying it is proof that new livestock screening procedures are working. Since October 2001, all cows slaughtered for beef have been tested for the disease. Agriculture Vice Minister Yoshiaki Watanabe said officials plan to thoroughly investigate the disease, as well as conduct discussions on how to improve the domestic surveillance system. They note that all four cows found to have mad cow disease were born in either March or April 1996, and Japanese officials will focus their investigation on cows born in the spring of that year. Officials note that all four cows may have been given the same milk substitute but they will not say whether the substitute is suspect. The instances of mad cow in Japan were the first spread of the disease within Asia. The disease devastated the cattle industry in Britain and other European nations, and has even spread to livestock in some South American countries. It has not managed to get into the United States. But mad cow is not the only livestock disease currently in Asia. Foot-and-mouth disease, which also hit Britain and parts of Europe last year, has cropped up in recent weeks in South Korea where officials said they would destroy more than 60,000 head of hogs to try to contain the disease. More than 40,000 hogs already have been slaughtered. Officials said they expect to have the kill completed by week's end.:
