American Beef Supply at Risk

The Canadian Agriculture Minister announced this week that a cow in Canada has tested positive for bovine spongiform encephalopathy, better known as mad cow disease. The United States immediately imposed a ban on Canadian beef and cattle imports, but the American beef supply may have already been placed at risk.

Canada has been the number one supplier of live cattle to the United States.[1] Last year alone we imported 1.7 million head of cattle from Canada.[2] We also imported $2.4 billion worth of beef[3]–that’s over a billion pounds of Canadian beef in the last year alone.[4] According to the National Cattleman’s Beef Association, about 7 percent of beef consumed by Americans is from Canada.[5] And because of NAFTA, there is no mandatory country of origin labeling from Canada, so there is currently no way for American consumers to know for certain if the beef they are eating came from Canada or not.[6] This is unfortunately not the first time the United States has imported cattle and beef products from countries at risk.

The United States General Accounting Office (GAO) is the investigative watchdog arm of Congress. Last year, the GAO released their report on the weaknesses present in the U.S. defense against mad cow disease.[7] They noted that “the United States has imported about 1,000 cattle; about 23 million pounds of meat by-products; about 100 million pounds of beef; and about 24 million pounds of prepared beef products during the past 20 years from countries where BSE was later found.”[8] Furthermore, the report said that if the disease did enter the country, current safeguards might not be enough to detect it and keep it from spreading to other cattle or to the human food supply.[9] The report can be downloaded here.

The discovery of a case of mad cow disease in Canada highlights how ineffective current safeguards are in North America. The explosive spread of mad cow disease in Europe has been blamed on the cannibalistic practice of feeding slaughterhouse waste to livestock.[10] Both Canada[11] and the United States[12] banned the feeding of the muscles and bones of most animals to cows and sheep back in 1997, but unlike Europe left gaping loopholes in the law. For example, blood is currently exempted from the Canadian[13] and the U.S.[14] feed bans. You can still feed calves cow’s blood collected at the slaughterhouse. In modern factory farming practice calves may be removed from their mothers immediately after birth, so the calves are fed milk replacer, which is often supplemented with protein rich cow serum.[15] Weaned calves and young pigs have cattle blood sprayed directly on their feed to save money on feed costs.[16] Michael Hansen with the Consumer’s Union reports that cows won’t eat feed composed of more than ten percent blood, evidently because of the taste.[17] Chickens, on the other hand, reportedly will eat feed composed of up to thirty-five percent blood.[18]

The reason why the American Red Cross continues to restrict blood donations from those who lived in Europe[19] is because of mounting evidence that indeed blood may be infectious.[20] In fact the mad cow outbreak in Japan has been tentatively tied to milk replacer.[21] Yet cow blood is still allowed to be fed to livestock in this country.

And the Canadian[22] and U.S. feed bans[23] also allows the feeding of pigs and horses to cows. Cattle remains can be fed to pigs, for example, and then the pig remains can be fed back to cattle.[24] Or cattle remains can be fed to chickens and then the chicken litter, or manure, can be legally fed back to the cows.[25] And the cow diagnosed with mad cow disease in Canada may have indeed been rendered into chicken and pig feed.[26]

D. Carleton Gajdusek was awarded the Nobel Prize in Medicine for his work on mad cow-like diseases.[27] He was quoted on Dateline NBC as saying, “it’s got to be in the pigs as well as the cattle. It’s got to be passing through the chickens.”[28] Dr. Paul Brown, medical director for the US Public Health Service, believes that pigs and poultry could indeed be harboring mad cow disease and passing it on to humans, adding that pigs are especially sensitive to the disease. “It’s speculation,” he says, “but I am perfectly serious.”[29]

Although the Canadian Food Inspection Agency admits the infected cow was sent to a rendering plant, the agency has tried to reassure consumers by describing rendering as a heat-treatment process used to ‘sterilize’ the carcass.[30] Unfortunately, the type of pathogen thought to cause mad cow disease is not destroyed by the rendering process.

Mad cow disease is thought to caused not by a virus, fungus or bacteria, but by a prion, or infectious protein. One reason prions are so concerning is that, unlike conventional pathogens, prions are not adequately destroyed by cooking, canning, or freezing.[31,32] Usable doses of UV or ionizing radiation, stomach acid, and digestive enzymes are all ineffective in destroying their infectivity.[33, 34] Even heat sterilization, domestic bleach[35], and formaldehyde sterilization have little or no effect.[36] One study even raised the disturbing question of whether even incineration could guarantee inactivation of prions.[37] National Institutes of Health expert Joseph Gibbs once remarked tongue-in-cheek to Cornell’s Food Science Department that one of the only ways to ensure one’s burger is safe is to marinate it in a concentrated alkali such as Drain-O.[38] Prions have been called the smallest,[39] most lethal self-perpetuating biological entities in the world.[40] Europe has forbidden the feeding of all slaughterhouse waste to livestock. The United States and Canada should do the same, according to William Leiss, President of the prestigious Royal Society of Canada.[41] The American Feed Industry Association calls such a ban a radical proposition.[42] The American Meat Institute also disagrees stating, “[n]o good is accomplished by…prejudicing segments of society against the meat industry.”[43]

U.S. health officials[44] and the Canadian Agriculture Minister[45]were quick to emphasize that only a single positive case was found. But Canada has been testing less than 0.01 percent of their cattle population for mad cow disease.[46] Canada now joins the ranks of other countries like Germany, France, Belgium and Italy that all confidently pronounced that they, too, were “free” of mad cow disease, until tests showed otherwise.[47] Will the United States be next?

The General Accounting Office was right to fault the USDA for inadequate testing.[48] Last year, the United States tested a little under 20,000 cattle for mad cow disease.[49] That’s less than Europe tests every day.[50] “This demonstrates that no cattle-producing country can think it’s safe,” Steve Bjerklie of Meat Processing magazine told USA Today in response to the Canadian discovery. “It really is a clarion call to the U.S. Department of Agriculture to step up surveillance in this country.”[51] More information about the inadequacy of mad cow disease surveillance in the United States can be found at

No one yet knows the source of the Canadian outbreak. It remains possible that the cow in question contracted the disease from local wildlife.[52] Chronic wasting disease is a prion disease of wildlife affecting deer and elk, and is endemic within the area where the infected cow was living.[53] The disease was exported there by the United States

Chronic wasting disease, also called ‘mad deer disease,’ seems to have started in Colorado, but has now been found in over a dozen states.[54] Just last year it crossed the continental divide into Wisconsin where a mass killing zone has just been set up to eradicate tens of thousands of whitetail deer in a vain attempt to slow the spread of the disease.[55] Chronic wasting disease seems unique in that the prions seem to be spread by casual contact between the deer. One can only hope that this disease would not be as infectious if it jumped from deer or elk into cattle (or into human beings for that matter).[56] Transmission to cows or people has yet to be documented, but the best available science suggests that it is possible.[57]

It was only last week when the Food and Drug Administration finally drafted up proposed voluntary guidelines recommending that deer and elk infected with chronic wasting disease, or at high risk for the disease, be excluded from animal feed.[58] This is a measure the World Health Organization and the United Nations Food and Agriculture Organization has been urging for years.[59]

Thankfully, Canada has a trace-back program in which all Canadian cattle are tracked throughout their lives. This should facilitate locating the source of the outbreak. The United States lacks such a program. U.S. officials argue that such extensive tracking isn’t necessary, because there has never been a case of mad cow disease detected in the U.S.. As one Alberta veterinarian responded, “we (Canadians) would have said that yesterday.”[60]

In response to the Canadian crisis, the Chief Executive Officer of the U.S. National Cattlemen’s Beef Association released a statement urging consumers to “continue to eat beef in confidence.”[61] “First,” the news release explains, “the Canadian case proves that the systems designed to protect consumers do work. The animal in question did not enter the food supply.” Based on the circumstances, though, it seems more like random chance that the cow got tested at all.[62] And had the animal instead entered a U.S. slaughterhouse, chances that it would have been tested seem even more remote.

The Cattlemen’s Association note specifically that Americans can be confident in the safety of U.S. beef because, “Animals with any signs of neurological disorder are not permitted to enter the human food chain and are tested for BSE.”[63] Yet the Canadian cow wasn’t necessarily displaying neurological symptoms. The Alberta Agriculture Minister Shirley McClellan explained the 14 week testing delay by noting that the cow didn’t appear to have BSE when it was condemned; it was underweight and thought to have pneumonia.[64] The provincial laboratory evidently just tested the animal as part of their routine 1 in 10,000 surveillance for mad cow disease.[65]

Fortuitously, though, the cow in Canada was deemed unfit for human consumption.[66] There’s reason to believe that if the cow had entered a U.S. slaughterhouse, not only might it not have been tested, it may have ended up on America’s dinner plate. According to an investigation of USDA slaughterhouse records, almost three quarters of cattle that were even too sick to stand were passed as fit for human consumption, including those who appeared sick with pneumonia.[67] The slaughter of these downed animals for human food is particularly risky now that mad cow disease has been discovered in North America. The downed animal investigation can be downloaded here.

The Cattlemen’s Association also feels consumers can be confident in the safety of American beef because “The BSE agent is not found in meat. It is found in central nervous system tissue such as brain and spinal cord.”[68] This can be viewed as irresponsible on two counts. First, American do eat bovine central nervous system tissue. Quoting from the General Accounting Office report: “In terms of the public health risk, consumers do not always know when foods and other products they use may contain central nervous system tissue… Many edible products, such as beef stock, beef extract, and beef flavoring, are frequently made by boiling the skeletal remains (including the vertebral column) of the carcass…”[69] According to the consumer advocacy organization Center for Science in the Public Interest, spinal cord contamination may also be found in U.S. hot dogs, hamburgers, pizza toppings, and taco fillings.[70] In fact, a 2002 USDA survey showed that approximately 35 percent of high risk meat products tested positive for CNS and CNS-associated tissues.[71]

The GAO report continues: “In light of the experiences in Japan and other countries that were thought to be BSE free, we believe that it would be prudent for USDA to consider taking some action to inform consumers when products may contain central nervous system or other tissue that could pose a risk if taken from a BSE-infected animal. This effort would allow American consumers to make more informed choices about the products they consume.”[72] The USDA, however, did not follow those recommendations, deciding such foods need not be labeled.[73]

Even if one avoids processed beef products, though, the possibility of prion contamination remains. While concentrations of prions may start out in the brain and spinal cord, they may not stay there. Before being exsanguinated, many cattle in the U.S. are knocked unconscious with a pneumatic gun, which uses an explosive burst of air that can blows bits of potentially highly infectious brain throughout the bodies of animals stunned for slaughter.[74]

Despite these shortcomings, both the U.S.[75] and Canadian agriculture secretaries[76] have scrambled to express their continued affinity for steak, reminiscent of the 1990 fiasco in which the British agriculture minister appeared on TV urging his 4-year-old daughter to eat a hamburger.[77] Four years later, young people in Britain were dying from an invariably fatal neurogenerative disease called variant Creutzfeldt-Jakob Disease–the human equivalent of mad cow disease–which they contracted through the consumption of infected beef.[78]

The General Accounting Office report concludes: “BSE may be silently incubating somewhere in the United States. If that is the case, then FDA ‘s failure to enforce the feed ban may already have placed U.S. herds and, in turn, the human food supply at risk. FDA has no clear enforcement strategy for dealing with firms that do not obey the feed ban… Moreover, FDA has been using inaccurate, incomplete, and unreliable data to track and oversee feed ban compliance.”[79]

The U.S. and Canada have basically the same safeguards in place, with the same loopholes and the same inadequate surveillance. If Canada has mad cow disease, then it stands to reason that the United States does as well. Either way, whether from the millions of cattle, or the billions of pounds of beef we imported from Canada previous to yesterday’s ban, American beef consumers have been placed at risk.

Michael Greger, M.D. is a nationally recognized speaker on a number of important public health and social justice issues. As Farm Sanctuary’s Chief investigator on mad cow disease, he debated the National Cattlemen’s Beef Association Director before the FDA and was invited as an expert witness to defend Oprah Winfrey in the infamous “meat defamation trial.” He currently coordinates the mad cow disease website for the Organic Consumers Association.

Dr. Greger is a general practitioner specializing in vegetarian nutrition. He is author of Heart Failure: Diary of a Third Year Medical Student and has contributed to a number of books on veganism and food safety issues. Dr. Greger is a graduate of the Cornell University School of Agriculture and the Tufts University School of Medicine.


[1] The Associated Press 21 May 2003

[2] Ibid.

[3] Financial Times (London) 21 May 2003.

[4] The New York Times 21 May 2003. [

5] The Atlanta Journal and Constitution 21 May 2003.

[6] Ranchers-Cattlemen Action Legal Fund News Release. United Stockgrowers of America. 21 May 2003.

[7]United States General Accounting Office. GAO Report to Congressional Requesters. January 2002 MAD COW DISEASE: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183.

[8] Ibid.

[9] Ibid.

[10] Kimberlin, R. H. “Human Spongiform Encephalopathies and BSE.” Medical Laboratory Sciences 49 (1992): 216-217.

[11] Canadian Food Inspection Agency BSE Fact Sheet. May 2003 P0091E-00.

[12] Food and Drug Administration 2000 CFR Title 21, Volume 6, Chapter 1, Part 589.

[13] Canadian Food Inspection Agency, Regulations: Food for Ruminants, Livestock and Poultry (Part XIV), “Prohibited Materials”

[14] Food and Drug Administration 2000 CFR Title 21, Volume 6, Chapter 1, Part 589.

[15] International Center for Technology Assessment. Citizen Petition Before The United States Food And Drug Administration. 1/9/03.

[16] Ibid.

[17] Kirchheimer, Gabe. Bovine Bioterrorism: The Perfect Pathogen. In Everything You Know Is Wrong. The Disinformation Company. 2002.

[18] Ibid.

[19] American Red Cross Addresses the Human Form of Mad Cow Disease

[20] Journal of General Virology 83(2002):2897-2905.

[21] Japan Today 24 August 2002.

[22] Canadian Food Inspection Agency, Regulations: Food for Ruminants, Livestock and Poultry (Part XIV), “Prohibited Materials”

[23] Food and Drug Administration 2000 CFR Title 21, Volume 6, Chapter 1, Part 589.

[24] Public Citizen. Letter to the FDA and USDA RE: BSE. 21 April 2001.

[25] Food and Drug Administration Sec. 685.100 Recycled Animal Waste (CPG 7126.34)

[26] National Post 21 May 2003.

[27] Unconventional viruses and the origin and disappearance of kuru. 13 December 1976.

[28] NBC Dateline 14 March 1997.

[29] Pearce, Fred. “BSE May Lurk in Pigs and Chickens.” New Scientist 6 April 1996: 5.

[30] Canadian Food Inspection Agency. Questions and Answers. Investigation of BSE case in Alberta.

[31] Taylor, D. M. “Bovine Spongiform Encephalopathy.” Medical Laboratory Sciences 49 (1992): 334-9.

[32] Lacey, Richard W. and Stephen F. Dealler. “The BSE Time Bomb?” The Ecologist 21 (1991): 117- 122.

[33] Marsh, R. F., and R. A. Bessen. “Epidemiologic and Experimental Studies on Transmissible Mink Encephalopathy.” Developments in Biological Standardization 80 (1993): 111-118.

[34] Dealler, S. F. and R. Lacey. “Beef and Bovine Spongiform Encephalopathy.” Nutrition and Health 7 (1991): 117-129.

[35] Dealler, S. F. and R. Lacey. “Transmissible Spongiform Encephalopathies.” Food Microbiology 7 (1990): 253-279.

[36] Holt, T. A. and J. Phillips “Bovine Spongiform Encephalopathy.” British Medical Journal 296 (1988): 1581-2.

[37] Brown, Paul, et al. “Resistance of Scrapie Infectivity to Steam Autoclaving after Formaldehyde Fixation and Limited Survival after Ashing at 360oC.” Journal of Infectious Diseases 161 (1990): 467-472.

[38] Gibbs, C.J. “BSE and Other Spongiform Encephalopathies in Humans and Animals: Causative Agent, Pathogenesis and Transmission.” Fall 1994 Food Science Seminar Series. Department of Food Science. Cornell University, 1 December 1994.

[39] Keeton, William T., et al. Biological Science New York: Norton, 1993.

[40] Hunter, G. D. Scrapie and Mad Cow Disease New York: Vantage Press, 1993.

[41] Ottawa Citizen 6 June 2001

[42] Evans, Eddie. “Agency to Ban Some Feeds to Block Mad-Cow Disease.” Reuters World Report 13 May 1996.

[43] “AVMA Casts Doubt on Spread of BSE Through Sheep Offal.” Food Chemical News 28 November 1994: 42-45.

[44] Washington Post 21 May 2003.

[45] Toronto Star 21 May 2003.

[46] The Record (Kitchener-Waterloo) 12 September 2002.

[47] Ibid.

[48] United States General Accounting Office. GAO Report to Congressional Requesters. January 2002 MAD COW DISEASE: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183.

[49] USDA News Release No. 0166.03. Statement by Agriculture Secretary Ann M. Veneman Regarding Canada’s Announcement of BSE Investigation. May 20, 2003.

[50] European Union. Monthly reports of Member States on BSE and Scrapie.

[51] USA Today 21 May 2003.

[52] The Washington Post 21 May 2003.

[53] Ibid.

[54] USDA Center for Animal Health Programs. Chronic Wasting Disease. 13 May 2003.

[55] Wisconsin Department of Natural Resources. CWD Management Zone.

[56] Connecticut Post 22 September 2002.

[57] European Molecular Biology Organization Journal 19(2000):4425-4430.

[58] FDA Talk Paper T03-34. 15 May 2003.

[59] What Canadians Need to Know About Mad Cow Disease. Canadian Health Coalition. 13 July 2001.

[60] USA Today 21 May 2003.

[61] National Cattlemen’s Beef Association news release. 21 May 2003. [62] Canadian Television Network 21 May 2003.

[63] National Cattlemen’s Beef Association news release. 21 May 2003.

[64] Canadian Television Network 21 May 2003.

[65] National Post 21 May 2003.

[66] Ibid.

[67] A Review of USDA Slaughterhouse Records for Downed Animals (U.S. District 65 from January, 1999 to June, 2001) Farm Sanctuary, October 2001.

[68] National Cattlemen’s Beef Association news release. 21 May 2003.

[69] United States General Accounting Office. GAO Report to Congressional Requesters. January 2002 MAD COW DISEASE: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183.

[70] “Health and Consumer Groups Urge USDA to Keep Cattle Spinal Cord Tissue Out of Processed Meat” Center for Science in the Public Interest News Release. 10 August 2001.

[71] USDA, Food Safety and Inspection Service, USDA Begins Sampling Program for Advanced Meat Recovery Systems, News Release.3 March 2002.

[72] United States General Accounting Office. GAO Report to Congressional Requesters. January 2002 MAD COW DISEASE: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183.

[73] USDA Response To GAO Recommendations on BSE Prevention. Release No. F.S. 0071.02.

[74] Garland et al. “Brain emboli in the lungs of cattle after stunning” The Lancet 348(1996):610.

[75] Chicago Tribune 21 May 21 2003.

[76] Toronto Star 21 May 21 2003.

[77] Chicago Tribune 21 May 21 2003.

[78] “Ministers Hostile to Advice on BSE.” New Scientist 30 March 1996: 4.

[79] United States General Accounting Office. GAO Report to Congressional Requesters. January 2002 MAD COW DISEASE: Improvements in the Animal Feed Ban and Other Regulatory Areas Would Strengthen U.S. Prevention Efforts. GAO-02-183.