Excessive pet urine destroys stuff, in case you were totally wondering...

If a picture is worth a thousand words, then it must also be worth about an 9.0 magnitude on the Richter Scale of smell. 

Be glad you can't smell this photo, because your eyes would water and you might want to take an immediate shower.

This is an image of what the subfloor looks like after carpet and pad were removed from a bedroom where a tenant kept a dog who who urinated excessively in the house (in violation of the rental lease, of course). In preparing this home for sale, BEFORE new flooring could be installed in this room, a contractor treated the subfloor with an enzyme in an attempt to kill the odor. They then had to apply an oil based sealer. And then new carpet, pad, and baseboards were installed, and the room painted. 

To remove and dispose of the carpet, pad, tackstrip, baseboards and get rid of the smell cost about $750, plus the cost of reinstalling new flooring. Overall this owner was fortunate that the pet urine seemed to be isolated to this one room, because doing this treatment throughout the entire 2000sf+ home would have been ridiculously expensive. For what it's worth, this owner is replacing all of the flooring and painting the entire interior of the house, so everything will be crisp and clean eventually. And the seller will disclose this to buyers...

The moral of the story: housebreak your pets. Or don't have them...