Vet gave us a kidney diet and he is point blank refusing to touch it, help

Bit out of my depth here so bear with me. Barney is 13, diagnosed with early kidney disease three weeks ago after the bloods came back off. Vet was lovely, sent us home with a prescription renal food and said this is the one thing shown to actually help him, so obviously I want to get it right.

Problem is he will NOT eat it. Sniffs it, gives me a look, walks off. He's been on the same supermarket pouches his whole life and clearly thinks I've lost my mind. I tried the wet renal and the dry renal, same reaction to both. He's now had about a day and a half of mostly picking at the dry biscuits he can steal from the dog and not much else, and I'm starting to panic a bit because the whole point was to help his kidneys not to starve him.

My brother in law reckons just take everything else away and he'll eat it when he's hungry enough, a cat won't starve itself. Is that right? Feels harsh but I don't know. How did people get a fussy older cat onto one of these diets?

Please do NOT do the starve him out thing, I know it's common advice and it's fine for dogs but it's genuinely risky in cats. I nearly learned that the hard way. Cats that stop eating can get a nasty liver problem within a couple of days, and an older cat that's already unwell is exactly the one you don't want to gamble with.

The thing that finally worked for us was going stupidly slowly. Like, a teaspoon of the new food mixed into his normal food, then a bit more every few days over about two weeks. Barney doesn't know he's being switched, he just thinks his usual dinner tastes slightly different each week.

Seconding the slow mix. Also warming the wet food made a huge difference for mine, ten seconds in the microwave, stir it, check it's only warm not hot. Something about the smell coming up.

One that surprised me: my old girl flat refused the pate version of her renal food but ate the same brand's chunks-in-gravy without complaint. Worth asking your vet if the diet comes in different textures, they're not all one thing.

Malcolm, the short answer to your brother in law's question first, because it matters: no, please don't starve Barney into it. It's the one piece of well-meaning advice I'd firmly put aside here. A cat that eats little or nothing for more than a day or two, especially an older or already poorly one, is at real risk of a serious liver condition called hepatic lipidosis, and it comes on fast. Getting calories into him, even the "wrong" ones for a day, beats a cat that isn't eating at all. Feeding his old pouches for now while you plan the switch is not a failure.

The method that works, and the one smudgesmum and two_tabbies have both landed on, is the slow transition: start with roughly nine parts old food to one part renal, and shift the ratio by about ten percent every two to three days, so the full change takes one to two weeks rather than overnight. Cats bond hard to the smell and texture they grew up on, so the tricks that tip it are warming wet food to just above room temperature, trying the diet in a different format (pate versus chunks versus the dry, as mentioned), and offering small amounts often rather than one big bowl. The site's guide to feeding a cat with kidney disease walks through why the renal food is worth the effort (it's mostly about controlling phosphorus), and wet versus dry cat food is useful here too, because the extra moisture in the wet version does a kidney cat a real favour.

The exceptions, and the reason I'd loop your vet back in this week rather than battling on alone: if Barney simply won't accept any version of the renal diet after a genuine slow attempt, that's a normal thing to report back, not a defeat. Vets have plan Bs, a different brand, a phosphate binder sprinkled on food he WILL eat so the ordinary food does less harm, or an appetite medication if nausea is part of why he's refusing (kidney cats often feel queasy, which puts them off food). And if he goes a full day or more eating basically nothing at any point, that's a phone call the same day, not a wait-and-see. None of this is a diagnosis of Barney, just the general playbook, your own vet knows his bloods and can steer it.

Update in case anyone finds this in the same flap I was in. Went slow like you all said, started at basically a pinch of renal in his normal pouch. Took about two and a half weeks but he's now on the full renal wet, warmed, and actually comes running for it. Vet also gave us a binder to use on the days he's fussy which took the pressure off massively.

The starve him out thing is officially banned in this house. Thank you, genuinely, you talked me down.