I manage a building with 10 2/1 apartments with a no pets allowed policy.  

She has people living in the unit that are not supposed to be there, she has a dog in the unit although the lease clearly states no pets and her mother (who is not on the lease) continues to smoke in and around the property although the lease clearly states "No smoking".

If I ever rent to tenants again, I will not allow pets over 25lbs and will base my tenant selection only on their credit and background checks.

Some common methods are through strategies like charging extra fees for covered parking or reserved spaces, renting out common areas for parties or events, adding or increasing pet fees, sub metering utilities, and converting unused spaces into storage units that tenants can rent.TIP: Ensure you understand any services that are included with tenant rents and the existing sources of miscellaneous revenue, if any exist.

Our plumber does give us a description of the blockage or issue and we screen this for tenant responsibility- ie superman was snaked out of the toilet, cat litter was dumped out of the now unusable garbage disposal (also interesting in non pet friendly properties) and we will pass that charge on to the tenant with appropriate explanation. 

A month ago one of my tenants in a 3 unit building notified me that they heard a mouse running through their walls and that they believed they were allergic to the dander and had to basically live on Benadryl.

Any Pets (if dogs, what breed)?

Max 2 pets.$500 pet deposit for up to two pets.

I know that if they are in fact service animals then they are not pets and you can not charge any fee for them.

I was able to use their feedback to offer them certain things like being able to have a pet in exchange for a new lease which allowed me to raise the rent immediately.