Best self-cleaning litter box for overweight cats

So you've got a bigger cat who needs a litter box that actually accommodates his size — that's a really practical concern that often gets overlooked when people shop for self-cleaning boxes. A lot of them have quite snug interiors that work fine for a lean 4kg cat but feel cramped for a heavier, broader-built boy. Before I point you in a specific direction: is the self-cleaning aspect mainly about convenience, or has he been avoiding the box at all? And roughly what's your budget — self-cleaning boxes range from around £300 to over £600, so it's worth knowing what you're comfortable spending.

Good to know — and 7kg is chunky but not unusual for a neutered male, so you're not in unusual territory there. The key things I'd flag for a cat his size: you want a globe or chamber with a wide opening and decent vertical clearance, because a box that forces him to crouch or turn awkwardly won't get used consistently. Some cats also become more selective about posture as they gain weight, so comfort really matters. Is he okay with enclosed spaces generally, or does he prefer open-style boxes?

Perfect — that actually makes this straightforward. My clear recommendation is the Litter-Robot 4. It has the largest interior of any mainstream self-cleaning box — the globe is genuinely roomy, with a wide-mouth opening that suits bigger cats well. At 7kg he'll be able to turn and position himself comfortably, which matters both for day-to-day use and for a cat whose mobility may change slightly as the vet works on his weight. It uses clumping litter (no proprietary stuff), the waste drops into a sealed drawer so odour is minimal, and the app lets you track usage frequency — which is actually useful if your vet wants to keep an eye on any changes in his bathroom habits, since that can be an early indicator of health shifts. It's around £499–£529 on Amazon UK, so it sits just at the edge of your budget but it's genuinely the right tool here. The cheaper alternatives have noticeably smaller chambers and I wouldn't recommend them for a cat his size.

Good question and yes, the Litter-Robot 4 handles this well. It uses a weight sensor to detect when a cat has entered and exited, and it's calibrated for cats up to around 11kg, so a 7kg cat is well within range. It won't false-trigger or struggle with his weight. The sensor actually becomes a bonus feature for you — the app logs his weight at each visit, so if he's making progress with the vet's plan you'll see a gradual downward trend over months, completely passively. One practical note: do run the unit during the day at first so he can see the globe rotate and get used to it — most cats adjust within a few days, but it's worth not rushing.

Great choice for his situation. To summarise: the Litter-Robot 4, clumping litter (unscented is best — overweight cats can be sensitive and you don't want anything that puts him off using it), and let him observe a few cycles before you retire the old box. If you keep the original box available for the first week or two alongside the new one, the transition is almost always smooth. Hope he gets on with it well — and good luck with the weight management plan.