Animal Ag: Mad Cow
When the British began to link "mad cow," or bovine spongiform encephalopathy (BSE), to the human disease Creutzfeldt-Jakob Disease (CJD), some predicted the UK could lose an entire generation to the epidemic. Fortunately, out of the tens of millions who inhabit (and eat beef in) Great Britain, the number of known deaths there linked to BSE does not exceed 200.
Although the total number of human deaths did not even approach anyone's worst fears, the economic fallout resulting from the UK BSE epidemic was crushing. Naturally, countries around the world seek to ensure that BSE has not invaded their borders. As the disease is capable of incubating and spreading undetected within an animal population, a handful of identified cases may signify a much larger problem.
About the Disease
BSE belongs to a class of illnesses known as Transmissible Spongiform Encephalopathies (TSEs). They are characterized by microscopic spongy holes in the victims' brains, and they are 100% fatal. TSEs have long incubation periods - a person may first show symptoms of the disease up to 40 years after they contracted it.
The first symptoms vary from strain to strain and from species to species. The victim may be forgetful, sleepy, anxious, clumsy, or aggressive. Eventually, the victim can no longer stand up, swallow, or talk. TSEs take anywhere from a few months to over a year to kill their victims after symptoms become apparent.
In addition to BSE, there is CJD, kuru, and Gerstmann-Straussler-Scheinker Syndrome (GSS) in humans; scrapie in sheep; and transmissible mink encephalopathy (TME) in mink. When tested, many if not all of these diseases are transmissible across a variety of species. However, the method of testing - injecting infected brains into the test subject - isn't exactly something that might happen to you by accident.
Despite decades of study, TSEs are not well understood. They don't provoke your body to get a fever or produce antibodies like you would if you got strep throat or a cold. Most illnesses are either transmitted genetically or they are infections, but TSEs appear to be both. A current theory is that they are transmitted by infections proteins called "prions."
There is no way to test whether you have a TSE while you are alive. The only way to check for a TSE is to examine the victim's brain for microscopic spongy holes upon his or her death.
Creating an Epidemic
It seems that TSEs naturally occur - rarely - through random mutations, affecting about one person in a million. Except in extraordinary circumstances, the disease dies with its victim, without infecting anyone else.
When a TSE occured among the cannibalistic Fore tribespeople of Papua New Guinea, the tribespeople ate the victim's dead body. Subsequently, more people developed this TSE, known as kuru, and passed it on to others when their bodies were eaten. The tribe faced extinction until cannibalism was identified as the cause and outlawed. The epidemic passed, but those who had engaged in cannibalism in the past continued to die of kuru up to 40 years later.
Just like the Fore tribespeople, British cows infected one another with BSE via cannibalism. In the 1980's, it become popular to feed cows the rendered remains of sheep, cows, etc. Such a practice solved two problems: it provided an outlet for waste that would otherwise go to a landfill (slaughterhouse leftovers, roadkill, euthanized pets, etc), and it fattened up the cows nicely. Presumably, the BSE epidemic in the UK began with just one infected animal entering the food chain.
Given the long incubation period and the lack of a test for living cows, nobody knew they had an epidemic on their hands until it was too late. As each unsymptomatic mad cow was slaughtered, rendered, and fed to more cows, the problem grew but never registered on anyone's radar. During this time, countless unsymptomatic mad cows went into the British food supply. When tens of thousands of cows began exhibiting symptoms, the Brits recognized the problem - too late.
Averting an Epidemic
To prevent the mad cow epidemic in the first place, the British could have forbidden feeding mammals to mammals. No cow, pig, goat, or sheep can eat cow, pig, goat, or sheep. To prevent an epidemic here, we can do the same. If, god forbid, a sick cow slips by, at least it won't infect an infinite number of others.
True, this will create a dilemma if we end up with millions of pounds of animal waste per year that was formerly fed back to animals. On the other hand, the economic fallout of an American mad cow epidemic are unthinkable. It won't just affect ranchers, dairy farmers, truckers, slaughterhouses, and restaurants - it will also hurt the pharmaceutical and cosmetics industries as they also use products from cows. We would also kill our markets for exports.
Are We Safe Here?
In the U.S., we've gone round and round with prevention strategies for TSE's. Without an actual epidemic on our hands, it's easiest for everyone to pass the buck. The cow people want to blame the sheep people, the sheep people want to blame the cow people, and so on.
When we had a fully funded depopulation approach to eradicating scrapie, someone was caught trying to cheat Uncle Sam out of cash by buying extra (low quality) sheep before reporting a case of scrapie and asking to be fully compensated for the destruction of his flock. When we had an unfunded depopulation program, anyone who reported a case of scrapie lost their flock in exchange for little or no reimbursement. Most people just buried the sick animals and hid the problem. When the sheep industry offered a voluntary scrapie-free certification program, nearly no one participated.
This shows that nobody wants to take the financial hit for BSE prior to an epidemic. Somebody needs to be the grownup, because as long as we engage in risky behaviors like feeding rendered mammals to cows, the fact that we haven't seen many cases of BSE yet is no comfort.
During much of the British mad cow scare, the U.S. protected itself with a "voluntary ban" on feeding cattle to cattle. Note that the feed and rendering industries did not sign onto the ban. In other words, we did nothing.
In 1997, the U.S. banned feeding rendered meat and bone meal from ruminants to ruminants but provided loopholes bigger than the hole in the ozone layer.
First of all, pigs are excluded from the law, so it is okay to feed cows to pigs and pigs to cows. In experiments, pigs CAN contract BSE.
Second, it is okay to feed chicken litter to cows and it is okay to feed cows to chickens. Chicken litter includes dropped chicken food (they are messy eaters), including cows.
Third, it is okay to feed cow blood to cows.
Fourth, check out the way Americans avoid feeding cows to cows: feed companies put a label on bags of food containing rendered cows that says (and this is paraphrasing) Don't Feed This to Cows. Good thing that'll stop anyone from trying!
Additionally, we test some cows for BSE. Given that it could naturally occur in about one in a million cows, we would have to test a lot of cows to find BSE. Other countries test MANY more cows than we do. We increased our testing a few years ago after finding our first mad cow, and then more recently we decreased testing tenfold. A representative of a consumer advocacy group calls the U.S. policy "Don't look, don't find."
Recipe for America advocates closing loopholes in BSE prevention (for instance, banning all mammalian livestock from consuming pork by-products) and allowing unlimited voluntary testing for BSE in addition to federal testing efforts.
More information
CSPI: Name That Cow - US BSE Precautions and Trade with Canada (article)Mad Cow USA: Could the Nightmare Happen Here? by John Stauber and Sheldon Rampton (book)
Mad Sheep: The True Story Behind the USDA's War on a Family Farm by Linda Faillace (book)
NYT: Stop the Madness (article) June 20, 2008. Advocates the U.S. allows the beef industry to test every animal for mad cow to alleviate Korean fears and protests about tainted U.S. beef imports.
WaPo: Video Reveals Violations of Laws, Abuse of Cows at Slaughterhouse (article) The article describes methods used to make "downer cows" pass inspection and enter the food supply. "Downer cows" are good candidates for mad cows, and they should NOT be eaten.
