I am currently rehabilitating a home that had numerous cats inside. Here is what works to take the pet odors out of the walls and floors. First, all of the carpet and padding must be removed. Next use a paint roller and apply oil based (kilz) primer sealer to the floors and walls. If the odor remains use "Nature's Miracle", a product found in pet supply stores. Be sure not to saturate the walls but lightly apply Nature's Miracle and let it dry and then reapply. A carpet that is in decent shape could use a good spray down of Nature's Miracle and a chem dry job. Good Luck!