Cat odors particularly those of males are generally more difficult than dog odors to remove. However both can pose a real challenge that can become quite expensive in the process. The first thought most home owners have is to wash everything down with bleach, this can make the smell worse and very difficult to remove. Pet stores and large hardware stores sell a pet odor neutralizing product which is especially formulated for the job. If this fails to rid the house of the smell you need to start a process.
The first step in ridding a carpet or floor of pet odor is to understand that the odors may be permanent despite your best cleaning endeavors.
The second step is to make a definite decision about what you prepared to do, and how far you are prepared to go.
Next is… what you are going to do? Are you going to try and salvage it or go ahead and replace it? If you decided to try cleaning it, the best suggestion is to have it professionally cleaned. Cleaning companies have special sanitizing and odor neutralizing chemicals that can be added to the cleaning solution to help rid the carpet of the offending odor.
If the odor is very strong, cleaning will probably not remove it completely from the padding under the carpet, in which case it will need to be replaced. This involves having the carpet removed and re-fitted over the new padding. If the smell lingers after carpet has been cleaned or replaced and the padding has also been replaced, the problem is deeply rooted.
Action will need to be taken quickly before the odor penetrates the new carpet.
The problem is that the odor has penetrated the flooring.
Depending of the severity of the odor, sections of a wood floor may need removed completely and replaced.
Wood or concrete that is not badly affected should be sealed with a blocking paint like KILZ, or a few coats of polyurethane.
Bottom Line: in most cases where there is a very strong pet odor there is no guarantee that the odor can be removed successfully without taking drastic action, which is in many cases is the removal of the flooring and sub-flooring.