Cat urine is probably the worst.  

Sometimes if the urine has really soaked into the sub floor sometimes the top layer is sanded down to remove before primer.

Completely destroyed by a dog's urine.

@Justin KnightenI’ve had some luck with fox urine.

Serial-cat-adoption homes, reeking of urine.

The recent renter had a cat that must have been urinating on the floors the past few years.

The court also noted that many of the city's concerns about STRs--noise, disorderly conduct, public urination, improper parking, public intoxication, etc.

The thing is all carpet are damaged to the point that I've been replaced them with the Planck,due to the very strong smell of animals urine.

The deferred maintenance was significant- 3/4 of the roof needed replaced, the hallways were incredibly dirty, 3 vacant units that needed complete rehab, residents had anything from holes in their ceiling to faucets shut off because they were leaking so badly, landscaping overgrown and/or dead, and the entire building smelled like cigarettes and urine.

On top of that they cover everything in their urine and other bodily matter and make your home smell terrible.I have no hesitation in recommending this product from Amazon http://amzn.to/2otjPjtJust to be above board it is an Affiliate link, but I now have four of these machines protecting my home and my family and we've been mouse free for almost a year !