Slightly off-topic perhaps, but I've been watching a you-tube channel called the minkenry about a guy in Utah who does rat extermination using dogs and trained
mink. I've gotten many a vicarious thrill from watching and cheering for the mink and dog to kill the little buggers!!

(he also hunts other things with them, so just be aware. no, I'm not a sadist, i'm just very,very frustrated and am glad to see someone else having luck with their extermination program). I think he's been helping/training others around the country to do the same?

Might be someone in your area? (no idea on cost, tho)