Dear friend,
Whenever a formerly clean cat starts soiling out of box he is trying to "communicate" "something"! Cats often "talk" with their waste so either he is not feeling well or he has stress.
I would give him one daily drop of unsweetened (only) cranberry juice.That will lower the PH of his urine in case he is experiencing a burning sensation. Also, give him one teaspoon a day of plain yogurt to replace the "good" bacteria in his system.
His pain could be related to an abscessed tooth or an internal issue so you will want to keep a close eye on him for any developing symptoms. If he can see or hear or smell any animals outside that can cause him stress so look into that possibility as well. Disinfect any soiled areas with an enzyme product like natures miracle so he can no longer smell his urine.
Please let me know if you have any more questions. I will be happy to help.
Very sincerely,
Terri
Dedicated to Cats and the people who love them!
Please press ACCEPT if my answer was helpful and leave feedback Thank you! Terri