IMO, it is a valid business move to allow pets in your residential properties. I'm sure tenants are relatively agreeable to pet deposits or having damages caused by pets deducted from their security deposits when they decide to move out. You should always make sure to include clauses in the agreement to make tenants liable for damages caused to the property anyway, so that's basically included. But the best argument would be this: any damages caused by pets would be mere cosmetic damages anyway (unless you allow them to keep elephants) so it will be relatively cheap to repair. Heck, you might even make a profit off the pet deposit!