Here's an interesting Wikipedia Article about Creekstone Farms, an Angus beef producer out of Kentucky. Apparently, they wanted to test all of their cattle for Mad Cow Disease (Bovine Spongiform Encephalopathy), but the USDA wouldn't let them
The USDA controls the sale of all testing kits of Mad Cow, so Creekstone had to take the USDA to court. Amazing, isn't it, that a government agency charged with protecting American citizens and their food would actually STOP a company from testing all its animals for BSE?
Read it Here
And, while you're reading about one "prion disease", you might as well read about another.
Warning, the following article made me gasp out loud in horror.
Scary Wikipedia Article