Using the bathroom on the bed?

My grandmothers cat was locked up in the bedroom one day for a few hours and used the bathroom on the bed. Now thats understandable because he couldnt have access to the litter box. But he has done it about 3 or 4 others times on the bed. Why do you think he is doing this? There is a new kitten in the house but i dont think that would make that much of difference. He is a un-neutered male. Please help with some advice

I recommend a trip to the vet to rule out any health problems. If there are no health issues, he could be marking his territory, especially since he is not neutered. Also, if the area where he went wasn't thoroughly cleaned with an enzyme cleaner (regular washing won't help), he will still smell where he had gone and will continue to go there.

i read a couple other peoples situations like mine and im almost postive that its the "area not being cleaned properly" He was just at the vet last week for his yearly check up and everything was fine. thank you. im going to tell her to get another litter box as well just in case.

It is generally a stress reaction, either from being locked up for the first time, or the smell of the new kitten has her upset.