Last week the United States Department of Agriculture (USDA) reported a case of atypical bovine spongiform encephalopathy (BSE), popularly known as mad cow disease, in a California dairy cow. According to USDA Chief Veterinary Officer John Clifford, the cow was "never presented for slaughter for human consumption, so at no time presented a risk to the food supply or human health." There was also no threat from the cow's milk because milk does not transmit mad cow disease.
The good news is that this particular animal was identified and immediately removed from the food supply. The USDA is quick to point out its success in this matter and highlight the dramatic reductions in cases of mad cow disease worldwide — in 2011 there were 29 cases of the disease among cattle, a 99 percent drop from a 1992 high of more than 37,000 cases. The reductions are a result of banning the use of processed cow products in cattle feed. It turns out that cow cannibalism caused what is considered the classical form of mad cow.
But the infected cow that died in California had an atypical case, the causes of which are still unknown. On the PBS NewsHour last week, Linda Detwiler, a clinical professor at the College of Veterinary Medicine at Mississippi State University, suggests that the "origin may be sporadic [meaning it just occurs], genetic, or it may be a modification of classical BSE."
Regardless of the type of mad cow, the consumption of its meat by humans is dangerous. The system worked in this case, but are there still risks? Are American eaters, who consume the most meat per capita in world, safe from mad cow?
The answer to that is a resounding yes, but with some caveats. Among the most pressing problem is an almost 90 percent decline since 2005 in the number of cows tested for BSE. The most recent case was identified only as part of a random testing program.
According to the Center for Science in the Public Interest (CSPI), an advocacy group that focuses on nutrition and food safety policies, the case calls attention to the limitations of the current animal tracking system. If, for example, it turns out that those cows with atypical forms of mad cow were contracting the disease because of a common exposure, the government would not be able to track potentially exposed animals. But more importantly, cows with other diseases, however rare, including foot and mouth disease and bovine tuberculosis, are also, under the current system, difficult to trace in an outbreak. Other countries have a more robust tracking system. Botswana, for example, uses "microchips to track its animals up and down the supply chain," according to CSPI.
The bottom line: we keep getting lucky. But if a new disease were to emerge or an existing disease were to break out, we would be at the mercy of tracking systems that remain antiquated and limited. New USDA rules are due out later this year, but only for animals that cross state lines. "The United States has first-world resources and technology but a Third World animal-identification system," said Sarah Klein, at the CSPI.
Americans should demand a safer food supply.