I am a pet owner myself and I try to be tolerant and acceptant of other's pets as well. I have tenants and some of them have pets. I know a lot of landlords do not accept pets and it sounds tough but a lot of times the units get destroyed due to pets.

Unfortunately, my experience has been that the owner of the pet (the tenant) is the one responsible for it. The pet can't help the fact that you didn't not walk them outside to do their business and now they have to go and it ends up on the carpet. And these are the same people that will destroy your property even if they didn't have pets. So, try not to punish the pet. Instead screen your tenants better with proper credit check, employment and references checked.