I've taken out a who warren before with a shotgun, they did had myxomatosis though seemed the right thing to do, did get a few looks though as it was about 200ft from a A road in a farmers filed, looked like I was going nuts blasting the dirt!
There was myxomatosis around here a while ago, seems to have died down now, but where i work (Food production) there lots of rabbits, squirrels etc around, things like that seem to spread fast.