I help manage rental properties with my inlaws and we do not allow pets, we used to... but it's SO hard to find people who will responsibly clean up after their animals. We've had our properties ruined on many occasions because the tennants refuse to clean up. Sure they lose their deposit, but to replace a carpet with something hard-wearing for a smaller sized house we're looking at just shy of $2,000, that puts us out of pocket $1,400 if the deposit was only $600. And that's just the damage to the carpets><.
The last house to have a pet in it took about $8,000 worth of damage; they'd locked the dog in the basement where it had constantly relieved itself (it had no choice) and the owners had never cleaned it up, the carpets were wrecked as was the linoleum in the kitchen and the house absolutely reeked. We can't even get our money back, we took them to court and they're all "HURR BANKRUPTCY".
I'm a serious animal lover but until the majority of the renting population can pull their heads out of their ass, I'll continue with my no pet policy>< haha. Not saying all renters are bad, I was a nice renter Q_Q;