13 year old Siamese peeing on bed/outside litter box
I have a 13 yr old Siamese female who has started peeing on my bed.
I recently sold my house and had to move in with mom until I can find a new home. She also has a young cat. I originally kept them seperated by keeping my cat in the basement. I finally realized that she had been peeing ALL over the new carpet. So, closed the basement and moved all of her food, litterbox, water, etc to my bedroom.
She did good for a few weeks and then she went on my bed......twice now.
I know this is not a medical condition. I'm confident that my cat is being stressed and territorial.
My question is how do I deal with this???? I am already going to have to replace $3000 worth of new carpet. And bedding for a California King bed. I also just spent $900 for my cat to go to the vet for an unrelated incident.
I am at my whits end. I am thinking of putting her down. She doesn't like anyone but me so no one will take her.
I will gladly take any suggestions because I can't handle it anymore!!!!