Under the North American Free Trade Agreement (NAFTA), there has been a dramatic increase in the integration of markets for live cattle and beef products in Canada, Mexico, and the United States. These markets were severely disrupted in 2003 by the confirmation of single cases of bovine spongiform encephalopathy (BSE) in Canada and the United States. The bulk of this disruption could have been avoided if the countries had developed more closely coordinated risk management programs based on the guidance of international standards. The BSE events illustrate that failure to address regulatory integration leaves integrated markets vulnerable to recurring disruptions.