When you speak to a former landlord, ask if the tenant caused any disruptions or paid on time and left the unit in good shape.

WSJ: Weeding Out Deadbeat Renters��WSJ House Talk

But if the tenant wants to bring a dog, you have a right to ask for a letter from a therapist or doctor that explains why the animal is necessary to use and enjoy the unit.

WSJ: Should 'Support Dogs' Be Allowed in No-Pets Buildings?--WSJ House Talk