Switching a senior cat off kitten food

A nine-year-old British Shorthair who's been on kitten food all this time — that's more common than you'd think, and the good news is it's fixable. Kitten food is calorie-dense and high in protein and fat, which is fine when they're growing but can stress the kidneys and contribute to weight gain in older cats. British Shorthairs are already prone to being stocky, so getting the diet right now really matters. Cats generally age more gracefully than dogs, but from around eight or nine they become more vulnerable to kidney disease, hyperthyroidism, dental disease, and arthritis — all of which nutrition can help manage. Tell me a bit more: has your cat had any recent vet checks, are there any health concerns on your radar, and what made you realise the food switch was overdue?

That's actually a really good position to be in — kidneys healthy, caught before any real damage, and the vet already flagging it. The core problem with long-term kitten food is the excess phosphorus and calories. For a British Shorthair carrying a bit of extra weight with kidneys you want to protect, you want to move to an adult formula that's lower in phosphorus, has controlled calories, and supports kidney function proactively. How heavy is she, roughly? And is she indoor only or does she go outside? That'll help me point you to the right formulation.

Perfect — that gives me a clear picture. For her I'd go with Hill's Science Plan Adult Light with Chicken, the dry version. It's specifically formulated for indoor cats prone to weight gain, has controlled phosphorus levels which matters for kidney health, and is a genuine step-down from the richness of kitten food without being a dramatic shock to her system. Hill's is one of the few brands where the kidney-protective nutrition is built into the standard adult range, not just the prescription line, which is important since her kidneys are currently healthy — you're being proactive rather than reactive. The transition should be slow: about ten days mixing old and new food, starting with 25% new and working up. Don't rush it. British Shorthairs can be stubborn about texture and flavour changes, so patience is worth it. You'll find the 1.5kg bag on Amazon UK — I'd start with that before committing to a larger bag, just in case she needs some coaxing.

That's the right question to ask. Hill's Science Plan Light uses higher fibre content to keep cats feeling fuller on fewer calories — it's not just a smaller portion of the same food, it's designed to maintain satiety. Most cats adjust within two to three weeks and stop pestering for more food once their gut adapts. If she's still seeming genuinely hungry after a month on the correct portion size, that's worth flagging with your vet — occasionally it signals something like hyperthyroidism, which can increase appetite. But for most cats in her situation, it works well. Measure her portions by weight rather than cup — British Shorthairs are good at looking desperately hungry even when they're not.

Focus on the dry food first — that's likely her main calorie source and the bigger nutritional shift. Once she's settled on the new dry food, you can gradually swap any wet food too, but doing both at once can cause stomach upset and makes it harder to know what she's reacting to if she does get an upset tummy. Hill's also does a Science Plan Adult Light wet food if you want to match brands eventually, but honestly the dry transition is the priority. Give it a month, let her settle, then revisit.