How to Fatten Up a Cat? Find Out Why Your Kitty May Be Thin

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Approved By: Dr. Sara Ochoa, DVM

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Cat too thin? Are you trying to find ways on how to fatten up a cat?

If you are in need of a way to fatten up a cat, you have a rather rare problem. Many times, people can't get their cat to stop eating! After you have determined why your cat needs to put on weight.

If you've recently taken in an underfed stray, several small meals enhanced with vitamin supplements will slowly but surely get him up to ideal weight.

Otherwise, you may have to find out what exactly is making Kitty lose weight and solve that problem first.

Remember: this is a cat, not a heavyweight boxer. You have plenty of time to gradually put on the pounds.

Why Your Cat is Thin

how to fatten up a cat

First of all, you have to identify why you need to get your cat fattened up. (It will be kindly assumed you don't want to eat the cat.) Did your cat have a litter of kittens recently? She may be burning calories just feeding her babies.

Does he share his food dish with other cats? He might be getting bullied out of his fair share. Does she go outside often?

She may have a parasite inside her that's digesting her food or maybe she lost a tooth in a scuffle. Is your cat elderly? Could be either a disease or just loss of appetite.

Very young cats will burn calories easily. A cat that's depressed or stressed out might just not be in the mood to eat. Always consult a veterinarian before making drastic changes to your cat's diet.


This is a common problem with senior cats that is caused by a benign tumor in the thyroid gland. If your cat's thyroid gland does not produce enough thyroxine-a this can cause the metabolism to speed up.

This will make it hard for your cat to keep weight on. Your veterinarian will need to run a blood test to determine if it is hyperthyroidism, diabetes or another cause.


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This is a parasite that lives in your cat's intestinal tract and digests the nutrients in her food before she can.Tapeworm is the most common culprit of weight loss. Bring your veterinarian a stool sample to test for this diagnosis. A dose of deworming medication will solve this problem.

Your veterinarian may prescribe something or you can use an over-the-counter pill depending on the severity of the situation.

Spending more calories than in taking

Kittens and adolescent cats have a lot of energy that they can burn off just running and playing. Don't discourage Kitty from exploring her world or honing her abilities with healthy exercise.

Just feed her kitten chow, which is formulated to be higher in protein and fat content than adult cat food.

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Get the high quality stuff without fillers that will make your cat feel full but won't actually cause the weight to stay on. Once your cat is old enough, look into spaying or neutering, which can slow the metabolism.

Why should you fatten up a cat?

No one likes to see poor, skinny kitty cats wasting away! Like any living being, a cat needs to eat and digest food to live.

If a cat is not eating or at least doesn't seem to be getting nourishment from food, you need to find out what's wrong.

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How to Fatten up a cat?

1. High Protein Cat Kibble

As mentioned before, you may want to try food formulated specifically for kittens as that has the most fat and protein. Read that label! If the first ingredient is a type of grain or “meat by-product” or something ending in “meal” it's no good.

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The first ingredient should be a type of meat such as turkey, fish, lamb, chicken or beef. Not only will high-protein food help your cat put on a healthy amount of weight, you may notice her coat becoming shinier and softer with other physical improvements.

2. Canned Cat Food

Maybe your cat doesn't care for the texture of dry food. Or maybe mouth pain or lost teeth is her reason for being reluctant to eat. Consider canned cat food. It's easy to digest making it quick to pack on the pounds.

Read the label again. You want to know what all is in the food and how many calories. In fact, canned food may work a bit too well in helping your cat gain weight, so use caution.

3. Try Some Pantry Items

Generally, you are discouraged from giving a cat people food, but desperate times may call for desperate measures. Don't feed your cat any foods that will only make the condition worse.

A small amount of plain, unsweetened yogurt on top of the food adds calories and entices Kitty to eat more.

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Canned sardines and mackerel are acceptable if packed in water rather than oil with no salt. Both yogurt and sardines have calcium and yogurt has probiotics. They're also both foods cats are fond of.

4. Offering treats throughout the day or in between meals

Treats should not be used for meal replacement as they are not very nutritious though they are high in calories. A few treats between meals can whet your cat's appetite though.

A few treats at a time will help your cat's weight slowly increase. Small portions served often may be what's needed.

5. A Little Home Cooking Can Be Helpful

One simple method to get Kitty to eat is to heat up her food just a little. This will intensify the smell, making it more appetizing to your cat. You may also want to try making her some eggs.

Scrambled eggs will be easier for her to eat. Just make sure the eggs are fully cooked. As said before, this is not a boxer, so no raw eggs.

Raw eggs contain avidin that makes it hard for her to absorb vitamin B plus there's the possibility of salmonella. Skip the salt, pepper and butter as these are not very good for your cat.

Eggs are high in the fat and protein your cat needs to put on some healthy weight. A bit of thoroughly cooked tuna or liver might help things along, but keep this small and infrequent.

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There are other methods depending on the situation. A sickly or highly reluctant to feed cat may need to be fed with a syringe. A cat that's being bullied out of his share by other cats may need to be fed separately.

A nursing mother just needs more food to help her replenish. Intestinal parasites can be dealt with by administering a few pills. In any case, talk with and cooperate with your veterinarian to find out which solution is best for your cat.

How to let your pet gain weight?

Underweight pets should be eating foods that are around 30% protein and 20% fat if they're eating dry kibble, or 7% protein and 5% fat, or higher, if you're feeding a wet food. Intersperse your pet's diet with small amounts of high-calorie supplemental canned food or canned products made of 100% meat sources.

How can I fatten up my cat that won't eat?

Give them some canned/wet food (the stinkier the better — try seafood varieties) Give them some meat baby food. Add some water from a can of tuna or anchovies to their food. Add a little bit of warmed, low-sodium chicken broth to your thier food, whether it's kibble or canned.

How many calories should a cat eat to gain weight?

If your indoor cat weighs 10 pounds, then they should be eating approximately 200 calories per day. If they weigh 15 pounds, then they should be eating approximately 300 calories per day to maintain their weight.

What should I feed my underweight cat?

Underweight pets should be eating foods that are around 30% protein and 20% fat if they're eating dry kibble, or 7% protein and 5% fat, or higher, if you're feeding a wet food.

  • Updated June 3, 2022
Mary Nielsen

A huge animal lover, born and raised around dogs, cats, chickens... Self-educated pet care nerd. Currently parent of three adopted cats and one small mutt. Animal adoption advocate. Loves a good book (about animals) and playing the piano.