I had this problem and one of my dogs died of lepto as a result, another got very sick and just about pulled through with a lot of care. My dogs are vaccinated and I was bleaching the yard every day but it wasn't enough. It was this time of year that that happened, whether that's relevant I don't know.
I put poison down, using heavy slabs on bricks as a "bait box" and also cut a little rat door into a locked shed and put a lot in there..it worked, and the few rats that wandered into the yard the dogs killed but didn't eat.
To the guy who said "shoot them with night vision", I shot do