Res Ipsa Loquitur

First, not all downers are diseased. Cows become unable to walk for a variety of reasons, some disease related, some injury related. Media hype aside, most of those are perfectly safe to eat. We've had cows that refused to walk after recovering from relatively minor injuries because, well, cows are just pretty damn dumb. Best I could tell, their thought processes went something like "Last time I stood up it hurt. Nope, not standing up again. Nosirree."

Second, not all cows that are infected with 'mad cow' show symptoms.

Indeed in Europe, where they test one out of every four cows, and Japan, where they test 100 percent of all cattle bound for human consumption, they have found a number of cases of mad cow disease in animals who appeared perfectly healthy.

Last year, we only tested about 10% of downers, so it was only chance that that cow that's making all the headlines was even checked. And she was unable to walk due to an injury from calving....not from 'mad cow'.

But, you're probably thinking, there's been a ban on mixing cattle parts into their feed for several years, so there's a low risk of US cows being infected. Think again.

The United States 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 U.S. feed regulations. You can still collect cow's blood at the slaughterhouse and feed blood concentrates to calves. In modern agribusiness, calves may be removed from their mothers immediately after birth, so the calves are fed milk replacer, which is often supplemented with cow blood protein. Weaned calves and young pigs may also have cattle blood sprayed directly on their feed to save money on feed costs.

And there's other potentially dangerous loopholes.

The U.S. feed regulations also still allow the feeding of rendered cattle remains to pigs, for example, and then the pig remains can be fed back to cattle. Or rendered cattle remains can be fed to chickens, and then the chicken litter, or manure, can be legally fed back to the cows.

Why? It's a very cheap source of protein for feed makers.

Clearly, the only safe response is first to mandate testing of all beef....and not just that intended for human consumption. There's some evidence that cats can get the disease, though it isn't known whether they can get it from eating tainted meat.

Second, we should ban the feeding of all animal parts to all animals intended for human consumption. If cows had been meant to be omnivores, they'd have sharp pointy teeth. I assure you they don't.

And just because we can process and make some use out of every part of a cow except the Moo doesn't mean we should.