I can have ten renters with dogs that are excellent, then I get one that wreaks havoc on a place and costs the owner thousands in cleaning or repairs. Do you honestly believe a Landlord is being unfair by protecting his property?
I highly encourage owners to accept pets with restrictions on the number, size, and certain breeds. I also require an increased deposit and require a professional carpet cleaning at their expense when they move out. Finally, I make them sign an addendum that spells out my requirements and shows that violations may be grounds for eviction. It works very well!
Lately I've been requiring rental applicants with dogs to show me proof of completion of an obedience course or they can bring the dog along when they apply to show the dogs is well behaved and trained with basic commands. Of course any seemingly well behaved dog can cause damage, but usually the owners that are willing to do this care enough that they are good responsible pet owners. ...because yes, there are definitely bad pet owners.
Nathan, I like your pet addendum approach. Any chance you can share a copy of that addendum with us?