All jokes aside, this is a very bad idea to be honest.

1. Those pet will shit and pee anywhere. Even if the owner clean it up but it still leave some stain, that is if the owner is a responsible type. Those who're not, they'll just leave it.

2. Dangerous dog breed like pitbull, I don't care what people said about their pitbull is obedient or good dog or soft hearted. Still won't take any chances with them, those breeds won't stop when they attack someone or other pets. Imagine the dog attacking some kids, stitches, bruises, probably lost some body parts.

Conclusion, this is a terrible idea.