Other odor treatments will mask the smell for awhile Good luck it's a tough job.. and pets don't belong in rentals. 

We had a temp write it up and didn't notice," then there may be no problem.Side note: I find it interesting that spelling is a pet peeve when you happily use "y'all" in a sentence  :P

It's blanket policies like Stephen E's that are responsible for the euthanasia of thousands of innocent family pets.

Regular inspections are mandatory (quarterly at a minimum) to insure the property is kept clean, no additional tenants have moved in and pets are properly managed. 

Prospective tenant asked that their bedroom be steam cleaned as pet dander.I have a dog.

Hi Ben,Get a few more bids, and make sure you do not buy services you do not need.In other words, find the lowest cost package of services that meet you needs.Walk the property with each pest bidder and if they point out things to fix, such as lids on garbage cans, holes caulked up in the siding, resident unwashed dishes in sink that should not be there...etc...Photo them with your phone and fix them.Be wary of the neighbors pets and kids when they prescribe a solution for you.

It sounds great, just like the pet rock when I was a kid.  

No issues with the dog, but I do want to request a pet deposit.

I've used my machine to get rid of smoke and pet odors.

If it's there, painters have primers they can use to (try to) cover the smell (the primers I know of have a heavy solvent smell for X hours and are not for pet or human occupied dwellings).You could offer two solutions (recommend air fresheners be used if they stay, AND (before move in) offer to let them out of the lease).