This video goes through the life cycle of a pet urine stain in carpet. It does a good job of explaining what happens when pet urine is deposited in your carpet and the issues that a pet urine stain can cause. Chem-Dry of Tampa FL uses a pet urine odor removal system called P.U.R.T. It stands for Pet Urine Removal Treatment. PURT does a great job of oxidizing urine stains in the carpet and rendering them harmless. It breaks down the urine in the carpet and the carpet pad underneath.
If you have pet urine odor in your home it might be time to call a professional pet odor removal service to get rid of it. Most consumer pet odor remover products work best on wet urine spots and are ineffective on dried urine spots. Once the urine crystals have formed there is no way to remove them without professional solutions and equipment.