I have 2 cats - Freyja who is a kitten around 6 months old & Velvet her mum who is 6.

Over the past 2 months, Freyja has picked & choosed when she wants to use her litter tray & does the toilet over the house. She has ruined my bedroom carpet, so much so I need to replace it. She has also occassionally pooed in the compartment of their cat tree & most recently is doing the toilet in the bath.

Initially I thought the issue was that I only had 1 box and it's a hooded one and she disliked that. So I bought her a smaller, open tray & she was using that on & off.

I clean out the clumped litter & poo twice a day & top up with litter once a day. Once a week I give the tray a proper clean.

I've also noticed that Velvet is constantly at Freyja, hissing at her & giving her a swipe. But other times, she'll clean her & be her best friend. Last night was the first time that I noticed Velvet hissing at Freyja because she was using the big box.

I stay in a one bedroom flat, so I don't have enough space to separate the cats. I have heard about getting a third tray but if she's not using either of the 2 I have, I really don't know what to do. I'm at my wits end.

The hooded tray is in the living room & the open tray is in the hall. I use clumping litter but have tried just normal antibacterial litter but no change.

It sounds to me like both cats are getting stressed. Have you checked to see if there is any medical reason why Freyah is having so many accidents like a UTI and you could try a Feliway diffuser to try and destress the cats? Its worth a try. Also, what about going back to basics with the kitten and keep putting her back on the cat litter tray periodically so she associates peeing and pooing in the appropriate place.

I understand how frustrating this must be for you

She got neutered 2 weeks ago & the vet said she was perfectly healthy.

I had a feliway diffuser to get the girls settled but I don't want to get another one because I don't want them to get reliant on it.
I work during the day so don't know how much use it would be putting her in the box occasionally at home.

I will get another box to see if that helps the issue but just don't know what else I can do.

We had a problem a few years ago with our elderly 16 year old with peeing all over the house and the vet recommended placing several cat litter trays in strategic places where she was likely to "go" and once she learnt that the tray is where the toilet is we could slowly eliminate tray by tray until there was only one left.

You could give that a go too. I know that means more expense initially with other trays + litter but its probably a small price to pay and got to be worth it in the end.

Yeah that's a good idea. I've been going through litter like no-one's business but if it means saving my house, it can't help! Plus poundland do decent boxes