There is no mistaking the heavy, ammonia smell of cat urine. Whether your cat is simply urinating wherever he or she wishes, or is spraying urine to mark territory, the result will be the same. This is a strong odor that will affect a surprisingly large area of the home, even if the problem area is relatively small. You should actually account yourself lucky if you are able to spot a puddle or a wet area on the rug or upholstery and begin treating it immediately. However, once the urine has dried, in most cases you will have to locate it by smell or by using a black light.
Odor Removal Once the Urine Is Found
Once you find out the problem area, it's important to take some care to remove the urine as completely as possible; not only for the sake of your nose, but to discourage your cat of thinking of that particular spot as a bathroom.
The organic compounds found in cat urine can pose some problems in removing the odor - some of the compounds are water soluble, but the uric acid not only is capable of binding to adjacent surfaces, but is not soluble by water. When you find fresh urine you should:
Wipe up the urine from hard surfaces with a paper towel and use the same to blot urine in furniture or rugs. Don't use cloth unless you are prepared to throw it away afterwards.
An enzyme cleaner is your best choice for removing cat urine. These cleaners are specifically designed to break down the uric acid into ammonia and carbon dioxide, which will simply off gas naturally afterwards.
Do not try to hasten the drying process after using an enzyme cleaner since it interrupts the normal dissipation of the ammonia and carbon dioxide.
Use the best enzyme cleaner possible - inexpensive cleaners often require multiple uses before they remove the odor of cat urine.
Be generous when applying the cleaner; you should soak the target area to allow the enzymes to really do their job.
After leaving the cleaner on for approximately a quarter of an hour, blot it up, then let the spot dry naturally.