I am trying to change the kind of food my cat is getting, and he is refusing to eat it. He is completely healthy, he passed his last annual physical without issue.

If I give him some of the old food, he eats it no problem. But he turns up his nose at the new food. I have heard some different schools of thought on what to do.

Some say, just give him the new food when he gets hungry enough he will eat it.

But someone else told me, if the cat goes without eating for to long it can be harmful to their health.

For a normal healthy cat, is there sometime in a battle of wills that the owner should give up and feed the cat what it wants?


4 Answers 4


When I've had to change my cats' food and they resist, I mix the old and new foods, slowly adding more of the new food, until after a few weeks, all I'm serving is the new food. In the beginning, the cat will pick-and-choose the OldFoodBits and leave the NuFoodBits behind; but gradually he'll start eating more and more of the NuFood. And the transition will be less traumatic, less chance of damaging his health. And you can also see if the new food is really really something he Absolutlely Won't Eat, or just something he needs to slowly get used to.

I know this doesn't answer the question in the heading - how long can a healthy cat go without food - but this might help you with the transition.

(Kind of like how Ebay changed their page background from its original yellow, to white. First people shrieked, so Ebay turned it back. Then they made it a shade lighter every other day until it was white...and almost no one noticed.)

  • 1
    That's why they did it that way. :) Fast change, people (any living thing) reacts to. Slow change? We literally don't notice it.
    – user2505
    Commented Jun 26, 2014 at 23:48
  • 2
    +1 for mixing it in in slowly increasing ammounts-that's actually the method described on the backs of most cat food bags (if you take the time to read those).
    – J. Musser
    Commented Jun 27, 2014 at 2:31

Cats can stop eating for a variety of reasons. They ate a bug, they have a hairball making them feel weird, they're stressed, they have a cold, there are a ton of reasons.

Feline Hepatic Lipidosis

The main danger when a cat stops eating is feline hepatic lipidosis, commonly called fatty liver disease.

The exact mechanism by which fasting in a previously healthy cat causes hepatic lipidosis is not clear. The process is unique to cats in both severity and rate of occurrence. It is understood as the anorexia continues more and more fat is broken down throughout the body and that this fat is then transported to the liver. The liver should then process this fat and export it back to the rest of the body in a new form. In cats developing hepatic lipidosis this process is impaired and fat accumulates in the liver. Damage to the liver occurs as a result of liver cells being too swollen with fat.

It's also not really well understood how long it takes for a cat to develop fatty liver disease, but it's believed that overweight cats will develop it faster than normal/underweight cats.

I had a cat with recurring anorexia (as a result of sinus problems) and the general timeline we followed was:

  • Day One: Offer Food, no pressure
  • Days 2-4: Initiate Force Feeding (high caloric density soft food with a syringe every 2 hours)
  • Day 5+: Hospital stay for regular liver monitoring (hospital staff continued force feeding)

Fortunately he never developed fatty liver (he was pretty underweight from these recurrent episodes). It's very difficult to get enough calories into a cat with a syringe, and if I knew how often we'd be doing it I would have had a feeding tube placed in his neck to aid in the feedings.


Another concern when a cat stops eating is dehydration, because cats get most of their water through their food (especially on a wet food diet). There are two ways to check your cat for dehydration at home.

  • Scruff test. Pull the skin of the scruff (the back of the neck) away from their body a short distance and observe how quickly it returns to place (a healthy cat should snap back immediately, a dehydrated cat will sort of slide back into place).
  • Gum test. Press your finger on the cat's gums. When you release your finger, there should be a white spot where your finger was. In a healthy cat, it'll take 1-2 seconds for that spot to return to pink. In a dehydrated cat it will take longer.

Dehydration can be easily treated, but a vet needs to examine the cat to be sure that there is not an underlying problem causing the dehydration.

When to See Your Vet

If your cat is dehydrated, you should see your vet immediately.

If your cat has not eaten for 2 days, you should see your vet immediately.

If it's a Friday and your cat just stopped eating and your vet isn't available on the weekend, call you vet and ask for advice specific to your cat's health and any existing conditions.

What to Expect

The most common treatment for anorexia is appetite stimulants. This medication is often used in addition to treating whatever the underlying cause for the anorexia may be. For example, in the cat with sinus problems, we would often give him antibiotics for the sinus infections and appetite stimulants to get him started eating again.

Feeding tubes are a treatment method for chronic anorexia, or anorexia that has progressed into hepatic lipidosis. It can sometimes be used as a treatment method in other cases of anorexia as well. For example, after a surgery, Juliet stopped eating due to stress. She hates being handled by people (medications, syringe feeding, etc), so I had the vet put in a feeding tube immediately and she was fine a week later. I believe that if we had tried to syringe feed her, it would have continued to stress her out (continuing the anorexia).

If your cat is also dehydrated, the vet may administer subcutaneous fluids to your cat, or use an IV for more intensive therapy.

Your cat may need to stay overnight or at the vet's for several days if she is very ill (from anorexia, dehydration, or from the underlying cause).

Avoiding Feline Hepatic Lipidosis when Changing Foods

This problem is most often seen when trying to change a cat from eating only dry food to eating wet food. To avoid the risk of hepatic lipidosis, you want the cat to be hungry but not literally starving. Feed roughly 1/4 of the cat's calories as the familiar food until the cat starts eating the new food.


When a cat starves, body fat is moved to the liver for processing. But the cat's liver can't handle it, and basically destroys itself. This is "Fatty Liver Disease".

So you don't want to starve a cat, as the results might be serious.

I suggest Leigh's solution to ease in the change gradually.

  • Related: en.wikipedia.org/wiki/Ketosis
    – Gary
    Commented Jun 26, 2014 at 23:41
  • if you lightly massage the part of the abdomen where the liver is located to give the fat processing a "helping hand", if you will, is it then ok to slightly starve your cat?
    – coburne
    Commented Jun 27, 2014 at 18:01
  • @coburne I have heard similar thoughts/ideas related to rabbits, can you post your comment as a separate question? Commented Jun 27, 2014 at 19:06

I would also make sure that there isn't another brand that he will like. Many cats just can't eat certain brands or kinds. My healthy cat can only eat one kind of food which i found out after months of research and worry. If he's rejecting it there could be a good reason for it and there are cases of people feeding their cats a food that's made them deathly ill.

I would shop around for something he likes.

  • Good point, I had a cat that liked expensive dry food. I could swap between flavors as long as I kept providing the "correct" 2 brands
    – SAM A
    Commented Jan 9, 2018 at 1:32

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