My friends Rottie(RB) got into poison in the garage and we rushed her to the ER vet where they gave her activated charcoal. Come to find out she was pregnant at the time and a few weeks later gave birth to about 4 or 5 puppies and only one of them lived (2 were still born).
But a Rottie is a large dog, your Fenway and JoJo are small animals so I'd be more concerned.
Maybe do a search online to get more suggestions on safe ways to rid your home of unwanted rodents. I would look, but I'm at work...shhh!
But definitely make sure the landlord has a plan of action on this as well. Like getting pest control to set traps along the perimeter of the building.

Good luck!