ARIA:
I wanted to ask you about mad cow disease. And I was reading about eating beef and the cattle they use for beef. Is that something we should be worried about, or what are we going to do about that?

CLAYTON:
Excellent question. I think the place to start, though, is with McDonald's, which is now a global business. So you have to be careful when you read a report that they found E. coli, or certain pathogens, in McDonald's hamburgers. McDonald's in London or Peking may have had that... But right now, there's a very thorough investigation by the USDA, and there are no identified cases of Mad Cow in the United States.

Livestock needs protein to be productive, just like we do, and one very economical way to supply that protein to them is to feed them other animals. It sounds a little bit sick, but, literally, in other countries old cows and old ewes were ground up and fed back to their children, because then that would increase the protein content in their feed. But in the United States, it's a law, you cannot feed animal products to food animals. So you don't have to worry about that line of transmission of the disease.

The main reassuring fact, however, is the fact that we've not identified any cases of Mad Cow in this country.

In fact, ironically, if Mad Cow disease were to occur anyplace in the United States, where do you suppose it might occur?

IVY:
Dogs and cats.

CLAYTON:
Dogs and cats. It would occur in our pets before it would probably occur in us, because a large amount of your dog and cat food, even if it's dry, is animal by-product.

JEFF:
Is Mad Cow disease a disease of muscle degeneration?

CLAYTON:
Of the central nervous system. Essentially, you lose control over your muscles, and that's how it's expressed; the animal loses control over its muscles, because its central nervous system is collapsing. The reason it's called "Mad Cow" is because the cows do things that we would consider to be very idiotic. They walk into walls, fences, then they'll knock themselves down trying to stand back up and continue to walk.