http://www.naturalblaze.com/2013/11/deadly-5-in-1-vaccine-kills-at-least.html
Only eight in two months?  Not a very effective way to get rid of the damn things, I'd say.
TRY HARDER, FOOKERS!
And are they still edible after this toxic concoction?
Probably not.  I don't think I'd feed them to my pet basilisk or chupacabra.