This video shows how Chem-Dry of Tampa FL removes pet urine from a rug using a sub surface extractor. The process is pretty simple using a specialized solution that's heated to 180 degrees we flush the area where there is urine and extract it at the same time. The solution is deposited all the way down to the bottom of the rug and then sucked out.
The solution is acidic which helps to neutralize any urine that is left behind. The lower pH is also safer for natural fiber rugs, like wool. The more acidic the solution the better it holds the rug dyes in place. Urine is got a higher pH and can loosen dyes in rugs. This way we are taking care of two problems at once. Getting rid of the urine and not putting the rug a t unnecessary risk.
If you have a natural fiber rug that your pet has urinated on be careful how you clean it. I have been to several homes in Tampa FL where the rug owner has tried to clean the rug themselves after a pet has peed on it. In a lot of those case the rug owner has made the stain worse. Using the wrong cleaning solution can make the spot worse and cause color damage. Even straight water can damage a rug if its applied to dyes that have been loosened by pet urine. When it comes to removing pet urine from a wool or silk rug I suggest leaving it to a professional rug cleaner.