We took in a cat who both urinated and defacated on our beds. I was going to take her to the pound and read that this sometime this is caused by emotions.
We had 2 dogs and 2 other cats.
I took her to a entirely new home without other animals where she was adopted by a window. They have a wonderful, non mess free household. I am glad I did not give up. Some animals feel to threatened to adjust to other animals and people, they get jelous. Good luck