KidneyCats

Appetite: the real battle

The short answer

A kidney cat who stops eating is usually nauseated, not stubborn. Uremic toxins and high phosphorus make her queasy, dehydration makes it worse, and cats learn to hate a food after one bad meal. Treating the nausea, warming the food and changing the texture beat hunting for a new flavor almost every time.

Why won't my cat with kidney disease eat?

This is the part that will take up most of your emotional energy, and it's where people feel most like they're losing. So start here: she isn't being stubborn, and she hasn't given up.

Eating makes her feel worse. Uremic waste products dull her appetite and make her queasy, and high phosphorus makes her feel unwell. Add the mild dehydration that comes with damaged kidneys and you have a cat who feels queasy most of the time.

Which means the answer usually isn't a better flavor. It's treating the reason food stopped being appealing.

Work through it in this order

Chasing food before you've dealt with the medical reasons is how people burn through forty cans and two weeks. There's an order to this.

Work through it in this order

One at a time. Mark each one off as you and your vet deal with it, and the next step opens.

  1. Nausea

    An antiemetic, given thirty to sixty minutes before food. This alone fixes a lot of cats, and many nauseated cats never vomit, so absence of vomiting is not evidence against it.

    Nausea and vomiting

  2. Stomach acid

    An acid reducer, if your vet agrees she needs one. Inexpensive, and it often goes alongside the anti-nausea medicine.

    The three shelves of drugs

  3. Phosphorus

    High phosphorus is a direct cause of feeling awful. Diet, or a binder, or both.

    Phosphorus binders

  4. Hydration

    A dehydrated cat is a flat cat. Fluids under the skin often bring her appetite back within a day.

    Subcutaneous fluids

  5. Her mouth

    A painful tooth or an ulcer looks exactly like nausea. Rule it out before you accept it is not that. Some clinics do careful dental work under anesthesia, and once a cat is stage 2 or beyond I treat the pain instead.

    Dental work and pain control

  6. Then, and only then, appetite stimulants

    They make a comfortable cat hungry. They do not make a sick cat well. Mirtazapine or capromorelin, and the dosing rules matter.

    Every medication explained

What to actually try at the bowl

None of this is a trick, and none of it costs anything.

Warm it. A few seconds in the microwave, stirred through, until it's about body temperature. Never hot, and check it with a fingertip. Cats eat with their nose first, and food straight out of the refrigerator has almost no smell.

Serve it fresh and take it away. Twenty minutes, then the bowl goes. Food that's been sitting out for four hours has gone stale and sour to a cat, and leaving it down mostly teaches her that food smells wrong.

Use a wide, shallow dish. Flat and open, so her face and whiskers aren't down inside a bowl. It takes ten seconds to try and it helps more cats than you'd expect.

Move the bowl. Away from the litter box, away from the noisy appliance, away from the other cat. Somewhere she doesn't have to keep watch while she eats.

Change the texture, not just the flavor. Pate, chunks in gravy, shredded, minced. A cat who has given up on pate will sometimes eat shredded without hesitating. Texture is a bigger lever than flavor and people almost always reach for flavor first.

Toppers, used sparingly. A spoon of the water from a can of tuna or plain chicken in water, crumbled freeze-dried chicken, a little low-sodium broth. Read the label on anything made for people and check there's no onion or garlic in it, which rules out most baby food and most gravies.

One new thing at a time. This is the discipline that matters and the one everybody breaks. If you open six cans tonight and she refuses all six while she's feeling sick, you haven't learned anything, you've just burned six options.

The appetite stimulants, and how to use them safely

Two drugs do most of this work. Both are prescriptions, both are useful, and both get used in ways that cause trouble.

Mirtazapine. A tablet, usually a small dose every two to three days rather than daily in a cat with kidney disease, because her kidneys clear it more slowly. There's also Mirataz, an ointment you rub into the inside of her ear, which suits cats who fight pills.

The ointment is where I want to be specific, because this is the mistake I see most:

  • Measure the ribbon against the tube. Don't estimate it, and don't add extra because yesterday's dose didn't seem to do much.
  • Wear a glove or a finger cot. It goes through your skin too, and you don't want a dose of it.
  • Alternate ears each day, and wipe the previous spot clean.
  • If she shakes her head and flings some off, that was still the dose. Don't top it up.
  • Too much mirtazapine looks like agitation. Constant loud vocalizing, pacing, restlessness, wide pupils, fast breathing, sometimes tremors. If that's what you're seeing, wipe her ear clean with a damp cloth and call your vet. If she's breathing hard or with her mouth open, skip the call and go now.

Capromorelin, sold as Elura. An FDA-approved appetite stimulant for weight loss in cats with kidney disease, given as a daily liquid by mouth, and it may not be available everywhere. Some cats drool at the taste, and a few get mild vomiting in the first few days.

Neither of these treats nausea. Worth repeating, because it's the usual reason they seem not to work.

Loads from YouTube only when you press play, so nothing is requested from Google before then.

Mirataz, applied properlyabout 1 minuteNot mine. A cat clinic showing the ear ointment applied the way the label means: the inside of the ear flap, a glove on, and the other ear next time.

Loads from YouTube only when you press play, so nothing is requested from Google before then.

Getting a reluctant cat to eatabout 9 minutesNot mine. Dr. Alex Avery, a veterinarian, on getting a reluctant cat to eat. The order he works through is the same order as the list above: nausea first, then warming, smell, the bowl, and hand feeding.

Weigh her, don't judge by the bowl

Appetite is a terrible thing to measure by feel. You'll remember the two good days and forget the four flat ones, or the reverse on a bad week.

Buy a cheap kitchen scale, sit her in a box or a carrier on top of it, and weigh her once a week on the same day. Write it down with the date. A quarter of a pound lost over a month tells you something no impression of her appetite ever will, and weight is the number I'd rather have at a recheck than almost anything else.

There's more on what's worth tracking at home on the monitoring page.

A wide shallow white dish of wet food on a wooden floor in morning light, beside a cheap digital kitchen scale and an open notebook with dates and weights written in pen.

The notebook is the real subject of that picture. A wide shallow dish, a cheap scale, and somewhere to write the number down is the whole kit.

What about a feeding tube?

You may hear one offered, so here's what it involves, and then what I do.

The usual kind is an esophagostomy tube, a soft tube that goes in through the side of her neck into the esophagus, her food pipe. The 2026 international guidelines say a tube can help cats whose appetite stays poor, especially later in the disease or during a crisis. It's worth discussing when she's still eating too little despite good nausea control and an appetite stimulant, because it lets you give food, water and medicines without a fight.

Living with one looks like this: it's placed under a short anesthetic, and she wears a soft wrap around her neck to protect it. Each day you give her food through it with a syringe and flush it with water. A tube can stay in for weeks to months, and it can be taken out when she no longer needs it.

It makes the most sense when there's good reason to expect better days ahead, such as a crisis she's recovering from. When she's late in the disease and the three things she loves most are going, a tube can end up adding time more than good days, and at that point the burden on her and on you can outweigh what it buys. The quality of life page is where I've written about telling those apart.

Referral and specialist hospitals place them regularly, and some general practices do too. I don't place them, and most regular clinics don't either. My reason is the anesthetic, because anesthesia drops blood pressure and kidneys that are already struggling don't get that lost function back. If you'd like the option, ask your vet who offers it nearby, what it's expected to do for her, and how her blood pressure will be protected while she's asleep.

The part I most want you to hear

You aren't failing at this because your cat won't eat. A cat who won't eat is a medical problem having a conversation with you, and there's nearly always something concrete to be done about it.

Early on, push for the kidney diet, because lowering phosphorus genuinely buys her time. Further along, the brand on the can matters less and her eating at all matters more. If she's happy and eating something, I'm not going to spend her good days arguing with her about food.

There's more on the food itself, including how to transition without triggering a refusal, on the kidney diets page.

Questions people ask me about this

Why won't my cat with kidney disease eat?
Because eating makes her feel worse, not because she's digging her heels in. Uremic waste and high phosphorus turn food into something unpleasant, and mild dehydration lays flat and queasy on top of that. A sore mouth and constipation are the other two regulars. Every one of those is treatable.
What can I give my cat with kidney disease to stimulate her appetite?
Two prescriptions do most of this work: mirtazapine, as a tablet or as the ear ointment Mirataz, and capromorelin, sold as Elura. Both are useful. Mirtazapine has some anti-nausea effect too, but neither is a substitute for an anti-nausea drug, so a queasy cat needs an antiemetic first or alongside. Don't set the schedule yourself, and with the ointment more is not better.
How long can a cat with kidney disease go without eating?
Not long, and I'd want you to take this one seriously. Two to three days of eating nothing puts her at real risk of hepatic lipidosis, where fat floods the liver and the liver stops coping, and that turns one illness into two. A day of eating far less than normal is a phone call that day, not a wait-and-see.
Is it better for her to eat ordinary food than nothing?
Yes, and it isn't close. Early on I'll push hard for the kidney diet, because lower phosphorus buys real time. Further along the brand matters less than the fact that she's eating. A partial mix of kidney diet and a binder stirred into food she likes recover part of the benefit, though a binder can only do so much.
Why does my cat lick the gravy and leave the rest?
Usually mild nausea. Interested in food but with a stomach saying no is exactly what gravy-licking looks like. A sore mouth produces the same behavior, because gravy needs no chewing. Either way it's a signal, and it's worth describing to your vet in those words.
Should I syringe feed her?
Not routinely, and not without your vet saying so. Forcing food into a queasy cat teaches her that food, being held still and feeling sick all turn up together, and she'll hold that for weeks. Treat the nausea first, because a comfortable cat mostly feeds herself. If she keeps eating too little despite treatment, ask your vet about the other options, which include a feeding tube.

Medically reviewed by Dr. Steve Pelton, last updated . First published . Reviewed quarterly.