3 cats, 1 litter box, outside elimination fix

Three cats sharing one litter box and you're seeing elimination outside it — honestly, that's almost a textbook outcome. One box for three cats is below the minimum most cats will tolerate, but before we get to box count, litter choice matters more than people realise. Cats are far more likely to use the box consistently when the texture and scent match their instincts — and most cats strongly prefer unscented, fine-grained litter over anything scented, regardless of what the packaging says. Can you tell me a bit more: are all three cats going outside the box, or is it one in particular? And are you currently using a scented or clumping litter?

That makes a lot of sense. Older cats often become more sensitive to strong scents as they age, and a covered box concentrates those smells significantly — imagine climbing into a small scented cupboard every time you need to go. The 8-year-old is almost certainly being put off by the combination of the scent, the enclosed space, and the fact that she's competing with two younger cats for one box. A few quick questions: any sign of arthritis or stiffness in her? And do you have any constraints on litter — dust levels, how much tracks around the house?

Right, that changes things in a useful way. With her stiffness, you want a low-sided open tray rather than a covered box — the hood is likely making entry harder for her on top of everything else. And with asthma in the house, you need something genuinely low-dust rather than just marketed as such. My recommendation is Breeder Celect Recycled Paper Cat Litter. It's made from compressed paper pellets, virtually no dust, completely unscented, and soft enough underfoot that arthritic cats tolerate it much better than clay or silica. It clumps loosely rather than rock-hard, so it's easy to scoop. The texture is different from fine-grain clay, but most cats adjust within a week, especially when you do a gradual switchover.

Both, honestly — but the litter switch is the more urgent fix and will likely show results fastest. The rule of thumb is one box per cat plus one extra, so ideally four boxes for your household. In practice, even going from one to three makes a huge difference. Place them in different locations so no single cat can guard access to all of them — that's a common issue in multi-cat homes. Switch to Breeder Celect in all of them so there's no inconsistency, and remove the hoods. If the outside elimination drops off with the litter change alone before you've added boxes, great — but I'd still add at least one more tray as a permanent measure.

The 20-litre bag is the right starting size for a trial with three cats — it's enough to properly fill two or three trays and do a genuine gradual switchover without running out halfway through. Mix it in with your existing litter at about 25% new to 75% old for the first few days, then flip that ratio by the end of the week. Most cats are fully on board within 7–10 days. If your 8-year-old takes to it, you'll almost certainly see her going outside the box less within a fortnight.