My first thought is that they're coming in under your foundation, so maybe you could spray a line of Raid fire-ant spray all the way around your perimeter (outdoors). But if the nest is under your house, the Raid won't do any good (it'll probably kill plants it touches, too, but might be worth the risk).
You might need to call an exterminator, who could have baits & poisons that are contained in a little box or something & not sprayed or dusted, in order to protect your home from having toxins floating about that the dogs would get into. I don't know if Home Depot or Lowe's might have baits you can buy there; would be a good place to try. Wish I had more than sympathy & a few lame answers to offer you. I hope you feel better & I'll see if I can think of anything more helpful!
If you're afraid of butter, use cream. ~~ Julia Child
As you cook, you enjoy omniscience about food that no amount of label reading can match. Having retaken control of the meal from the food scientists, you know exactly what is in it. (Unless you start w/cream of mushroom soup, in which case all bets are off.) To reclaim control over one's food, to take it back from industry & science, is no small thing; indeed, in our time, cooking from scratch qualifies as subversive. ~~ Michael Pollan