||12-16-2009 04:09 PM
Does he still use the box too? Have you changed litter brand?
If you let the box go too bad, he may have spite peed or just peed elsewhere. Now that he's done it, he'll keep going back there. Make sure you clean the affected area thoroughly, and if possible, follow up with some of that cat pee eating enzyme. If he no longer smells it, he may stop using the area.
Finally, a visit to the vet is a good idea, as a sudden change in behavior is often a sign of a developing health issue. I sincerely hope it's not that. I discovered this first hand and lost one of my cats earlier this year to a large sarcoma in his tummy.
After an appropriate mourning period, we went to the adoption center and instead af getting one cat, we got two more. We now have four, and I keep telling my wife we are on the road to becoming crazy cat people. However, the little bastards are a brother and sister, so we couldn't break them up, and they are cute as the dickens, whatever that is, and they've really injected a lot of life into the two aging boys we already had.