Mad Cow and CWD
This is a good article on Mad Cow, Chronic Wasting Disease, and other scary illnesses.
CWD attacks deer and elk. As the author points out, there is evidence that these diseases (Transmissible Spongiform Encephalopathies) can sometimes jump the "species barrier", so that infected deer herds might lead to Mad Cow in this country.
Swan notes that "if it is ever found that CWD can jump the species barrier to livestock or humans, a war on deer and elk will occur. "
He's right about that. Wisconsin had an outbreak of CWD south of Madison, and the DNR had not choice but to slaughter as many deer as possible over a 256 square mile area. (Read more here).