Hi @Travis-and-Angel0 - as @Helen3 mentioned you can have a rule that the animal cannot be left unattended.
and yes, we have had multiple times where the animals clearly were not service animals. They were poorly behaved when we could see them, dragged owners out doors, didn't come when called, barking and so on.
You can't really 'do' anything. You can try and guilt people from doing this. It's poor behaviour.
We have now added that the main booker is financially responsible for any damage caused by such animals to help alleviate poor behaviour along with the not being left alone.
good luck!