He's a 13 year old male, and he become unreliable about the litter box when a new cat was added to the household about 5 years ago. He seems to have reached an adequate accomodation with her--he's not obviously afraid of her, and sometimes stares her down, but he isn't willing to share a litter box much. He might well be ok as an only cat.
He's a pet-quality purebred, so he doesn't have the perfectly flat Persian face--no breathing problems.
He usually, but not always, gets on my case when he's used a plastic bag on the floor and wants a new one, so I think he's got some idea of having a place to go.
Sometimes his behavior improves when he's given Bach flower remedies (I've tried Rescue Remedy, Willow (for grudges), and Beech (for nothing-anyone-else-does-is-good-enough perfectionism)). Aside from that keeping up with his demands for fresh litter is simply getting unmanagably expensive, he only seems to be affectionate with me when he's been given a flower remedy. This may prove that I'm not a great cat mom, but I'm not willing to do this much work and put up with this much aggravation for a cat that doesn't like me.
If anyone knows of cat-fostering or homes for senior cats or a no-kill shelters in the Philly area, please tell me. If they're somewhat further away, I might be able to work something out, so let me know anyway.
I am very much afraid that this will end with him being put down and I hate the idea, but I've been putting up with cat piss here and there more than I want to take.