You need a little more information on Mad Cow

I just know it.

And, just in case you haven't read Rampton and Stauber's Mad Cow USA (neither have I), here's a little info from Geov Parrish at Working for Change.

1 - Regulators are having a hard time figuring out where, exactly, the Mabton cow came from in its life's journey. It had apparently been born in Canada, sold several times, and lived in multiple states. In all likelihood it contracted BSE as a calf -- perhaps through the use of artificial milk, given to factory calves because it's cheaper (and because mom is long gone). The fake milk is protein-enriched through being sprayed with freeze-dried cow blood. Beyond the cow-cannibalism, that's also a great disease vector. The prions that spread BSE are impervious to freezing or high heat.

2 - ["Downer cow"] meat does not go into the human food supply - but the diseases that felled them can. The cows' meat is instead mixed in with grain (for extra protein) and fed to chickens, on the reasoning that viruses, bacteria, and the prions that carry BSE don't affect chickens' digestive systems. Assuming that's true, it goes straight through the birds instead - into their manure, which is then used by many organic farming operations as a fertilizer. Remember that, vegetarians, and vegans the next time you eat carrots or potatoes without peeling them.

3 - The initial symptoms of BSE only emerge, and are testable, four or five years after contamination. Many of the cows that wind up in our nation's food supply are slaughtered before any symptoms of BSE could appear.

4 - For the worst corporate violators, the ones actually inspected and found to be egregiously violating food safety laws, the penalties are slaps on the wrist. Many large operations consider such fines a cost of doing business, a pittance compared to the money they save through mistreatment of the animals, fouling of the environment, and careless handling of the meat.

5 - Creutzfeldt-Jakob Disease is well-established in the U.S.; some 300 new cases are diagnosed each year. News reports that no cases of CJD have ever been confirmed in the U.S. are only technically true; CJD can only be confirmed by autopsy, and beyond the expense, handling the brain tissue of someone infected with CJD, even in a highly controlled laboratory setting, is simply too dangerous. This disease is with us, and contaminated meat is almost certainly one of the ways it has spread.

6 - For meat, such problems are usually avoidable by buying organic meat free of antibiotics and the ravages of factory farming. In fact, for nutrients and taste as well as food safety, organics in general are well worth the higher price. Just peel your carrots before you eat them.

Do not call my plant physiology professors, but would the prions that carry BSE which make their way into fertilizer collect only in cells on vegetable peels? I'm gonna need a little more information here.

In the meantime, here's what you have to look forward to if you contract a prion-caused disease:

The diseases are characterised by loss of motor control, dementia, paralysis wasting and eventually death, typically following pneumonia.  article

You could always just stop eating.

....but hey, do what you want....you will anyway.