And that, folks, is why there is a big disclaimer at the bottom of each page warning you that the answer you get may not come from a lawyer, and may be incorrect. There is no such rule, anywhere.

I would suggest telling him that if he doesn't recover his animals expeditiously, you will arrange to have them picked up by animal control. I suspect he left you with the animals because he knows they make you uncomfortable.

Did you identify your state in there somewhere? As you were told when you posted, laws are different in each state.