I have both a persian and a himilayan cat that share a litter box. Lately my oldest (3 year old himilayan) is pooping outside the litter box on the carpet. What does this mean and how can I prevent it from happening?
This could be a sign of illness or it could be a behavioral problem. Try buying a new litter box so that you have 2 boxes, and see what happens. If this does not work, I recommend a visit to the vet.