` ` They 're not looking very hard for mad cow disease , '' says one of USDA . Last year , 29 cases of BSE were reported worldwide , down 99 % from the peak of 37,311 cases in 1992 . South Korea is the second - largest producer of beef from the United States . In people , symptoms of mad cow disease include psychiatric and behavioral problems .
` ` They 're not looking very hard for mad cow disease , '' says one of USDA . South Korea is the second - largest producer of beef from the United States . In people , symptoms of mad cow disease include psychiatric and behavioral problems .