Feel like your cat is too skinny? There are many reasons why your furry friend might be underweight, but luckily, there are plenty of lifestyle changes that will help your cat maintain a healthier body type.

In this article, we’ll talk about why your cat might be underweight, as well as what you can do to help them gain weight.

Is your cat really underweight?

How to Help Your Cat Gain Weight

Obesity is a very common problem- so much so that it’s become normalized. Before you try to get your cat to gain weight, it’s imperative that you make sure they’re genuinely underweight, and not just slim- otherwise you could quickly push them into obesity.

We can really get an idea of the scale of the obesity problem when we see that 63% of cats are overweight or obese. But this becomes even more complicated when you learn that 73% of cat owners think their cat is a healthy weight. This shows that many people who think their cat is healthy probably have an overweight pet, and many people who think their cat is skinny probably have a healthy cat.

So how can you tell if your cat is actually underweight? The most reliable indication that a cat is underweight is if you can see their hips, ribs, or spine through their coat. You should be able to easily feel these bones, but not be able to see them. If you cannot see any of these bones, chances are your cat doesn’t need to gain any weight.

Still unsure as to whether your cat is underweight? Don’t hesitate to take them to the vet- many vets will offer free appointments to check a cat’s weight and body condition.


Why is my cat underweight?

There are a number of reasons why your cat might be underweight. Cats can be underweight due to issues with their diet, so you may need to change the amount or quality of food you are giving them. This is more common with kittens than adult cats.

Some kittens also struggle to gain weight due to a cleft palate or other issues that make it difficult for them to eat and drink.

It’s more likely for cats to be underweight as the result of an ongoing health problem. Some of the most common health issues that cause weight loss are parasites, diabetes, cancer, kidney failure, gastrointestinal problems, dental problems, and hyperthyroidism.

All of these issues need to be addressed by a vet, first and foremost. Feeding more food to a cat in renal failure won’t help. Feeding more food to a diabetic cat to try to get them to gain weight may make it worse. It’s very common for recently adopted cats to be underweight, particularly if they were strays.

How To Help Weight Gain in Kittens

How to Help Your Cat Gain Weight

It’s important for kittens to consistently gain weight as they grow. If your kitten hasn’t been weaned yet and you notice that they are not gaining weight, double check to make sure that you are mixing the formula to the exact specifications on the package. If the formula is watered down too far, your cat won’t get enough nutrients. If the formula is correct, get them to a vet to be thoroughly checked for congenital problems such as cleft palates and heart conditions.

If your cat has already been weaned, you’ll need to keep an eye on them for worms and other parasites, as these are more common at a young age. Many vets recommend worming kittens every couple of weeks. Talk to your vet about appropriate food for their age, and make sure they are getting a diet that is nutrient-rich. However, you’ll want to make sure that you aren’t overfeeding them, as this can lead to obesity later on.

How to Help Weight Gain in Adult Cats

How to Help Your Cat Gain Weight

It’s rare for an adult cat to be underweight, so be sure to take them to the vet to identify any potential health problems. Keep a close eye on their behavior – if they’re losing weight, it might be because they are bored of their food or don’t enjoy the taste. Switching to a different brand of food can entice them to eat more.

Make sure that they have food available to them throughout the day, with options for both dry food and wet food.

How to Help Your Cat Gain Weight

If you have a senior cat that is losing weight, it is particularly important to take them to the vet to rule out health problems. This is an age when kidney problems often start to develop.

If your vet rules out a bunch of health issues, it’s possible that your senior cat doesn’t have the appetite to keep up with her calorie needs. You can try switching to a type of food that is specifically for senior cats, or switch to a wet food, which are often more palatable and have a higher calorie density.


Before you try to put weight on your cat, you should make sure you’re positive they need to gain weight- many more cats are overweight than underweight, and this is partly driven by a misunderstanding of the ‘normal’ body shape of a cat.

If you are sure your cat is underweight, you should first visit your vet, who will help you to determine if there’s an underlying reason why. This is essential- without treating or understanding the underlying reasons why your cat is underweight, you’ll be fighting a losing battle.

Once you’ve worked out what is going on, a change in diet is often all that’s needed to help cats gain weight.