Japan Blasts US Safeguards Against Mad Cow
US hit by 'mad cow' disease scare | Mail OnlineThe United States tests only a small percentage of the 35 million cattle slaughtered a year, targeting older animals or ones that show symptoms of the disease.
Dunno the date, but since the Daily Mail is "fact" for the right, then here is the link.
Doubts raised about effectiveness of North American screening for mad cow disease
Now all this happened half a decade ago, but I some how doubt that the US has increased testing to the same degree as in Europe and Japan....Both Canada and the United States have increased the number of cattle tested by each government for the disease, but the testing remains woefully inadequate by the standards of the European Union nations and Japan.