Britain’s “Mad Cow” Dilemma

By Awake! correspondent in Britain

IN November 1986 an alarming disease appeared for the first time among Britain’s cattle. Since then, over 11,000 animals have been infected, with up to 200 new cases reported each week. While the disease is technically called bovine spongiform encephalopathy, or BSE for short, the media quickly labeled the sickness “Mad Cow” disease on account of its distressing symptoms.

What is BSE, how did it originate, and why is it of such concern?

BSE is a form of dementia in which parts of the brain are destroyed by abnormal proteins described as “unconventional infectious agents.” When seen under a microscope, the affected organ has a spongy, holey appearance. As the disease progresses, the animal becomes irritable and loses weight, and when it is no longer able to control its limbs, it collapses and dies or has to be destroyed.

Cattle developed BSE from scrapie, a closely related dementia common in British sheep. How did this happen?

Modern Cattle-Feed

A cow is a grazing animal that chews the cud and normally exists on a diet of vegetation, mainly grass. In recent years, however, British cattle-feed manufacturers have added an unnatural protein supplement to normal feed. This consists of slaughterhouse waste, including sheep carcasses infected with scrapie, that is crushed, cooked, and dried. Not only have cattle been affected but five types of antelope, including a rare Arabian oryx, have also died in British zoos from brain disease. All were fed this commercial cattle-feed. Ranch mink have contracted a related disease, believed to be a result of their being fed raw sheep offal.

Tests reveal that both BSE and scrapie are unusually resistant to high temperatures, ionizing radiation, and ultraviolet light. Normal cooking and other forms of sterilization will not kill off these mysterious agents. Although there is no firm evidence that humans have ever been infected by scrapie, the worrisome question now is: What risk does BSE pose to humans who eat beef products?

The Human Link?

“Nobody need be worried about BSE in this country or anywhere else” is the official British government view, expressed by John Gummer, the minister of agriculture. But not everybody is so sure. Richard Lacey, professor of clinical microbiology at Leeds University, England, writes in The Independent newspaper: “If the cow acquired the disease from its feed, then the route of transmission, at least initially, was oral. This raises the possibility of oral transmission to man.”

In line with such reasoning, Germany has banned all imports of British beef because they cannot get an assurance that it comes from BSE-free herds. The United States has banned imports of cattle, embryos, and cattle semen from Britain. The U.S.S.R. has gone further, banning also imports of British sheep and goat meat, along with dairy products, on account of BSE. Some schools in England have decided only to serve beef from herds certified free of the disease.

The government has, among other measures taken, prohibited the sale of certain beef offal. The British public annually spend well over $3 thousand million on beef and beef dishes, such as burgers and pies, and need to be reassured that their health is not at risk. Yet, “it may be a decade or more before complete reassurance can be given” that BSE is not transmissible from cattle to humans, admits an official government report. “The difficulty,” explains Dr. Richard Kimberlin, former director of the Edinburgh Neuropathogenesis Unit, “is the length of incubation period. If BSE does pose a public health risk, by the time this has become manifest as an increase in the number of patients with CJD, it would be too late to do anything about the population already exposed.”a

Meantime, scientists are urgently seeking new, positive evidence to allay these fears, and the British government has set aside $20 million to help in this research. But as the British Medical Journal soberly points out: “The safety of beef has not yet been tested and may not be testable.”

Would You Eat It?

Whatever the outcome to human health, the BSE debate has drawn public attention to the practice of recycling animal waste. British cattle and poultry continue to be fed processed chicken litter, known in the trade as DPM (dried poultry manure), a mixture of feces, feathers, and dead birds. Dried pig’s blood, flavored with chocolate, is given to calves. Although illegal as cattle feed since July 1988, whole sheep heads, along with sheep offal, are still ground up and fed to pigs and poultry. Such practices are condemned as “unnatural” in one official government report. Some may justify them on the basis of expediency and economics in food production. But healthwise, are they worth it?

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[Picture on page 17]

Transparency of vacuolation (holes) in brain of BSE-affected cow

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J.A.H. Wells, Crown Copyright Material