Dog pee smell - stained hardwood floors

[Kat Rathell]

We asked our tenants to move out due to the blatant violation of the 'no pet' clause, but the damage has been done, and the unit reeks of dog pee. The floors are dark, so we have no idea as to the source, and it has been a few months. 
Has anyone been successful at eliminating the dog pee smell from hardwood floors where you had to treat the entire floor (2-3 rooms)? How did you accomplish that? Is that something you can deduct from the deposit, and if so, can you only deduct supplies, or also labor if you hire somebody to do it?

It really sucks because it was a newly rehabbed unit, they were only our 2nd tenant and the floors were in fantastic shape before they moved in :(.