If the odors are from a pet that still lives in the house, eliminating odors is probably a waste of time and money; most pets will revisit their favorite spots regardless. Ridding carpets of odors from pet urine is expensive, time consuming, and not always effective. Nevertheless, try this:

1) Call a carpet installer and have the carpet and pad removed; dispose of the pad and order a new one.

2) At a pet store, buy a liquid enzyme-based odor remover and ask to rent a black light.

3) Go over the carpet and through the room with the black light to locate every trace of urine, which should show up under the light. Circle the areas with chalk.

4) Saturate the marked areas with the enzyme, following label directions. Allow to dry completely, for several days.

5) Seal the subfloor with a stain blocker, such as KILZ, and then have a new pad and the carpet reinstalled.

6) If necessary, have the carpet professionally cleaned.