I just found this website
Pet Friendly Rentals - Install Search Tool | Pet Friendly Rentals
Your just install the extension and when you are looking at rentals on realestate.com it highlights pet friendly places!!! Thought it would come in handy for you.
I just tested it. Works you wait a few seconds after the page loads and it circles around each property that is pet friendly/pets negotiable, hopefully this will be helpful for you to find a house