Elderly cat - advice needed please

[StorminaBcup]

Our cat is a 21 yr old rescue cat (we adopted him aged 4.5yrs). He has kidney failure, hyperthyroidism and is losing his sight (which also means he’s no longer going out). This past week he has been pushing his water bowl around the kitchen and has started peeing on the kitchen floor (still seems to use his tray though).
We take him to the vets for checkups quite regularly due to his age and the vet said he was in good health for his age last week (he has a sore on his front paw for over grooming, which we have cream for).
The vet also gave him a pain blocker as his legs weren’t extending properly (vet said it was like carpal tunnel syndrome).
He’s still eating, drinking and coming up for cuddles but needs help grooming.

Firstly, any ideas what the change of behaviour with water bowl / peeing in the floor could be (stress? Dementia? He’s had the same bowls for years so no recent changes).

Secondly - will vets be honest about quality of life and at what point do we call it a day (possibly more for future but happy to take advice).

Thanks in advance!

I have found my vets wanted to have my cat PTS more than I did and I was always saying no.
She was 20 and at the stage or your cat, you may find she's dehydrated, it makes them confused and they start doing odd things. with kidney failure, also affects the legs but your cat probably has some osteoarthritis too.
I finally knew it was the end when she lay down in the cupboard and wouldn't come out or eat or drink. Up until that weekend she had been ok.
It's generally pretty obvious when the end is nigh - they offered rehydration etc but having had cats with kidney disease before I said no because I knew it was futile so I just had her gently PTS.
Its always heartbreaking

Sorry to hear about your cat

That’s really helpful, thanks for taking the time to reply. He’s fine in himself, aside from these new behaviours so will keep an eye on him. It’s reassuring to know that it’s clear when they’ve had enough, I’m not sure he’s at that stage yet. He’s still very vocal when it comes to meal times!

We’ve moved his tray so he doesn’t have to go up and downstairs and this has helped, but I may get another tray to make it easier for him to access and hopefully reduce accidents.