Here's another site:

Where do we draw the line on animal experimentation?
It is likely that more than a few animal activists came unglued at the admission by Senate majority leader Bill Frist that, during his medical training, when faced with a lack of animals for vivisection projects, he "adopted" cats from animal shelters in the Boston area, then killed them doing medical experiments. "It was a heinous and dishonest thing to do," Frist admitted. "I was going a little crazy." In a Boston Globe article, Frist is described as an animal lover whose "decision to become a doctor was clinched when he helped heal a friend's dog." Certainly, Frist's means of obtaining animals for experiments is deserving of damnation, but are those types of experiments themselves equally heinous?
http://cats.about.com/cs/advocacy/a/vivisection.htm

THAT should be enough right there to keep him off the bench. "Heinious and dishonest, I was going a little crazy"
DAMN!!!!!!!!!!!