Hughes knew that the meat from a single cow couldn't make very many people sick. The real danger was if the disease was passed to other cows. How could that happen? After cows are slaughtered, the parts you can eat go to meat processing plants to be made into hamburger and steaks. The parts you can't eat–like the bones and hooves–are often sent to factories that grind them into meal for animal feed. So the infected parts of the sick cow, like the brain and spinal cord, could have been put in the feed. If so, the disease could spread from herd to herd, creating a mad cow epidemic, or widespread outbreak. Hughes studied the report to learn the facts of the case. —When Birds Get Flu and Cows Go Mad! How Safe Are We?, John DiConsiglio How would the disease pass to other cows? The disease passes from mother cows to their offspring. All cows contain the virus and need to be treated for mad cow disease. Animal products not eaten by humans end up in food for animals, which can make them sick. Cows that share the same pasture will make each other sick.