My cat pees all over the apartment everyday

[Feduphuman]

My indoor male cat was diagnosed with cystitis around a year ago. He pees blood, a chronic health issue caused by stress. It leads him to associate the litter box with pain so he doesn’t like to use the litter box every time he pees. He pees on average around 4-5 times an hour. Mostly in the litter box but throughout the day and night he pees on the entire parameter of the apartment.
I try to limit his access to the other rooms in the apartment as much as I can because without hesitation he will pee in those rooms too. I spend so much time cleaning every single day and it is driving me insane.
Me and my husband have tried new food, new toys, new litter, feliway, Uti medication, more water in his diet, being home more often. You name it, and it has been done. As time goes on it gets worse.

Extra info:
-he has no access to outside
-we have another cat (girl, same age 3 years) and she uses the litter box just fine

[fjm]

What is stressing him? I think resolving that is the key to improving things.

[Ruth B]

Am I reading that right, he is peeing every 10 to 15 minutes all day, every day. If that is the case then something is seriously wrong, You say he was diagnosed with Cystitis a year ago, but has he seen the vet since and if so what was the outcome.
I agree that getting to the bottom of the stress problem is certainly needed, and I would think after so long a referral to a behaviourist might be the best option, particularly if you can get one that will work with your vet to provide a more holistic approach providing both medication while sorting out the stress issues.

Of course there are always the more common questions that might provide a clue as to why he is stressed out.
How many litter trays do you have around the house, while normally for 2 cats he suggestions would be 3 litter trays, with the current problem I would suggest having one in every room so no matter where he is he is always near a litter tray.
How well does he and your other cat get on. While cats can seem to get on well and there may not be any sign of obvious aggression, passive aggression can be just as serious, is there any times when your other cat blocks routes through the house, particularly routs to litter trays, food or water bowls, the best sleeping places etc. Not being able to move safely through the house can be a cause of the stress.
Have you tried other types of litter, if he associates one type with pain, if your vet can minimise the symptoms so he isn't in pain, it could be that he will be willing to accept a different type of litter, or a different style of litter tray.
If he is kept in side all the time are you sure it is still the Cystitis and not a territory problem, or it could be both, if he can see other cats outside it could be he feels he has to mark his territory to protect it, and is also getting wound out about the cats he can see.

With out actually seeing his behaviour and the way he interacts with your other cat, we can offer possibilities. I do hope you can get to the bottom of it, as it isn't pleasant living like that for you, and he certainly isn't a happy and healthy cat at the moment.

[Mollycat]

Agreed if a cat is peeing several times an hour he would need serious medical help. My ckd cats have never peed more than a half dozen times a day at most. If so, please get him to the vet urgently.

Is he neutered? Is he peeing, or spraying?