EhlerDave, have you thought about keeping your dogs inside for a few days and using some poison, then giving a couple days, clean up dead rats, remove remaining poison and turning dogs back out? That bad of a rat problem, I would almost consider boarding dogs for a week to go full on war on rats.
I may have to try something like that. Not sure how yet but will be thinking on it. The dogs are both inside dogs, may try this as soon as my Daughter has her first surgery. The dogs will want to stay in with her and we will have help here to keep an eye on them when they must go out.