Catster logo

How to Tell if Your Cat Is Underweight: Vet-Reviewed Signs to Look For

Skinny cat
Image Credit: Poto69, Shutterstock
Last Updated on November 16, 2023 by Kerry-Ann Kerr

Vet approved

	Dr. Lorna Whittemore Photo

Reviewed & Fact-Checked By

Dr. Lorna Whittemore


The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

Feeding your cat a healthy diet, one that will ensure they stay at an appropriate weight, is crucial. However, you might be doing exactly that, but your cat is still shedding the pounds. If you suspect that your cat is losing weight, despite there being no changes in your routine, consult your vet immediately. There are some things you can do at home first to either confirm your suspicions or alleviate your fears. We’ll go through those together, what signs to look for, and what may be causing the sudden drop in weight.


How to Tell Your Cat Is Underweight

Figuring out if your cat is underweight can be a challenge, but don’t worry; we’re not asking you to try and wrestle your kitty onto a set of scales. There are two things you can do at home.

The first is the Body Condition Score, which vets use to evaluate a pet’s weight and is like BMI for humans. You can find a chart at your vet or online from organizations like American Animal Hospital Association and World Small Animal Veterinary Community.

The second thing you can do is the Hand Test. Feel your cat’s ribs, which you’ll find behind their front legs. Their weight is perfect if they feel like the back of your hand. If their ribs resemble your knuckles, your cat is skinny. If their ribs feel like your palm, they’re potentially overweight.

These at-home tests are a way to determine whether or not your next stop is the vet. If you can feel a pronounced ribcage or spine, a vet can do a more thorough exam and determine the cause of the weight loss.

Causes of Weight Loss

skinny cat
Image Credit: Aun25, Shutterstock

There are two main reasons for a skinny cat: they’re using more energy than they’re taking in, or they aren’t eating enough.

A cat can lose its appetite for several reasons, including stress, nausea, dental disease, organ dysfunction or a host of other reasons. Weight loss can be age-related, as a decline in organ function and muscle mass is more common in senior cats.

Where Do I Start?

Monitor your cat’s eating, and make sure they’re finishing their food. Does your cat seem hungry after it’s eaten? Different food brands have feeding requirements based on age, size, and activity level, so double-check that you’re following these correctly.

If you have more than one feline, ensure one cat isn’t hogging all of the food and leaving the other with a rumbly tummy. Separating cats into different rooms to eat is a solution if your cats are becoming a little competitive during mealtimes.

Symptoms of Weight Loss

While a skinny cat doesn’t necessarily mean there’s a medical emergency, one that stops eating must be examined by a vet.

Cats that don’t eat for days can develop fatty liver syndrome, a life-threatening condition also known as hepatic lipidosis. Arguably, rapid weight loss is easier to spot than gradual weight loss, so you’re not just looking out for a cat that stops eating altogether. These are signs to look out for if you suspect your cat is losing weight:

  • Bad breath
  • Diarrhea
  • Drooling
  • Eating more/less
  • Lethargy
  • Loss of muscle, especially around the back legs and spine
  • Peeing or drinking more than usual
  • Poor coat condition
  • Very vocal/more demanding than usual
  • Vomiting

yarn ball divider

3 Ways to Help Your Cat Gain Weight

Once your vet has ruled out any underlying health conditions, you can try these tips to help your cat get back to a healthy weight.

1. Change Up Your Routine

Hungry cat near empty bowl
Image Credit: Crazy nook, Shutterstock

It could be that your cat just needs more food. You could add more meals, or maybe your cat would like the option of choosing when to eat. You could allow your cat to “graze” instead of eating larger meals throughout the day.

2. Change Their Food

Has your cat started a new diet recently? Maybe it doesn’t agree with them. Try a different brand or flavor or change protein sources, which would also rule out if food sensitivities or allergies are what’s causing your cat’s weight problem. Your vet will be able to help with choosing a diet.

If your cat eats kibble, try adding water or unsalted chicken broth to their food to make it more appealing. Heating food in the microwave can also make it smell better, which may entice a curious cat to eat. If you change your pet’s diet, consult your vet for advice.

3. The Environment

As we already mentioned, if you have multiple cats, try feeding them in separate rooms in case one cat is stopping another from eating everything it wants.

Examine the room with the food bowls and see if anything is preventing your cat from enjoying its meal? Maybe their bowl is next to something loud, like a fan or a furnace. Try changing where you feed them to see if this solves the problem.

cat + line divider

Final Thoughts

If you suspect your cat is underweight, you must contact your vet as soon as possible. The weight loss could be related to the environment, cat food, or a health condition. Whatever it is, you can devise a plan with your vet on how to tackle this problem together and get your cat back to a healthier weight!

Featured Image Credit: Poto69, Shutterstock

About the Author

Kerry-Ann Kerr
Kerry-Ann Kerr
Kerry-Ann lives in Scotland and wishes her garden was bigger so she could have her very own Highland cow but thinks her dogs probably wouldn’t like that idea very much. She has a La Chon called Harry who was poorly with a liver shunt when he was a puppy. It wasn't likely he would make it into adulthood, which was difficult to comprehend, but he beat the odds and is a healthy old man now. She also has a Pug called Maddie who is a big foodie. She’s small, sassy, and every day she finds a new way to wind her brother up.

Get Catster in your inbox!

Stay informed! Get tips and exclusive deals.


Follow Us

Shopping Cart