I'v had Phoenix for 3 years and he was totally litter trained. Then all of a sudden he stopped using the boxes. (I have 2 cats) I took him to the vet to see if he had any physical problems and he checked out just fine. The vet informed me it was probably a behavior problem. I answered all his questions about any changes in the household. There were none. He said.. "bad kitty" and gave me a few suggestions. None of them worked! I'v had Phoenix ever since he was a kitten. He was neutered at 5 months. Any ideas? Thanks, Buzzbee