There are several methods to cleaning up pet urine accidents from carpet. If you are looking for a DIY method, here's a great resource with a few different methods.
While homemade and store-bought cleaners have their place, but many pet stains are difficult to remove and can only be completely removed by a professional carpet cleaner. Often pet urine soaks through the carpet, reaching the subfloor and pad as well. Basic cleaning methods only clean the surface, leaving behind an odor deeper in the carpet. A professional carpet cleaner can help remove these deeper stains.