Cornish Rex litter box advice

A Cornish Rex turning their covered litter box into a personal den is pretty classic — they're intensely curious cats and that enclosed space is just too tempting to resist. The problem is that once it becomes a hideout, it stops being a reliable toilet. Most litter boxes are also too small to begin with; cats need a tray at least 1.5 times their body length to feel comfortable going in and turning around. Covered boxes compound this because cats can feel trapped, and for a playful breed like a Rex that's especially true. So: how big is your cat, and is she actually still using the box consistently, or are you finding accidents elsewhere?

That tells me everything. The covered box has crossed the line from litter tray to territory in her mind, and the bathmat accidents are her trying to toilet near what should be her box but not wanting to disturb her den. You need to switch to an open tray, and because she's using the space as a retreat, you'll want to make sure the new tray is genuinely roomy so it doesn't feel like a downgrade. For a 3.5kg Cornish Rex you're looking at a tray around 50–55cm long at minimum. What does the current covered box look like — does it have a swinging door or is it fully open at the front?

Right — she's not afraid of it, she's claimed it. That's a different problem and an open tray solves it completely because there's nothing to claim. My recommendation is the Savic Nestor Giant open litter tray. It's 56cm long, so comfortably 1.5 times her body length, the sides are high enough to contain scatter from an active digger — which Cornish Rex definitely are — but there's no roof or door, so no den potential whatsoever. It's straightforward, easy to clean, and available on Amazon UK. One thing: place it in the same spot as the old covered box, but remove the covered one entirely rather than leaving both out. If she has the option to retreat to the covered one she will.

Yes, transfer a small scoop of used litter from the old box into the new one before she first approaches it. Her scent in there signals that this is her toilet space. Keep the litter depth at about 5–7cm — Cornish Rex tend to dig enthusiastically and they like enough material to work with. Don't use a liner in the Nestor Giant; they can snag claws and put cats off. Give it three or four days and you should see the accidents stop. If she starts treating the new open tray as a nap spot too, that's less likely with no enclosure but if it happens, just gently move her out and don't make a fuss of it.

Good — it should sort things out quickly. Cornish Rex are smart enough that once they understand what the space is for, they tend to use it reliably. If you want to give her a legitimate den elsewhere — a covered cat bed or a box with a blanket — that often helps redirect the impulse entirely. Good luck with her.