Skip to main content

PawTracks may earn a commission when you buy through links on our site.

7 common reasons your cat is losing weight and throwing up

You’re almost asleep, and then you hear it — the pitiful retching sound of your cat throwing up. All cat parents have been there, and the occasional hairball is normal. Cats groom themselves obsessively, and all that hair has to come up (or out) eventually. You can’t help but feel sympathy for the poor little thing, but it’s ultimately no cause for concern. But is your cat losing weight and throwing up? What causes a cat to lose weight in the first place? We’ll delve into the most common reasons cats lose weight, what you should do about it, and when it’s time to see your vet.  

An orange and white tabby cat grooming their paw.
TeamK / Pixabay

Why do cats lose weight?

While weight gain in cats is a frequent concern due to related health problems like heart disease and arthritis, it’s equally alarming when your fur baby suddenly begins to lose weight. You’ll want to keep tabs on her diet if you notice unexpected weight loss so you can make a note of whether your cat is eating the same amount as always or she’s lost their appetite. From minor issues with digestion to more serious ailments, there’s a variety of reasons why your cat might lose weight. 

Recommended Videos

Common causes of weight loss and vomiting in cats

Let’s take a look at potential reasons why your cat may be losing weight and throwing up. 

Food allergies

In addition to vomiting and weight loss, cats suffering from food allergies may be lethargic, suffer from diarrhea, scratch or bite at their fur, and experience hair loss. You’ll want to speak with your vet, as they may ask you to bring your cat in for a checkup. Your vet will also suggest trying out different food, such as a grain-free formula or prescription diet.

Regurgitation

Does your cat vomit a log of undigested food? Just like us, cats get excited when it’s time to eat — sometimes a little too excited. When cats eat too quickly, their food doesn’t have time to digest, and they end up regurgitating it. While seeing your cat vomit is always distressing, there’s an easy fix. Feed your fur baby smaller portions more frequently, and she should be able to digest her food without becoming ill. 

Kidney problems

If your cat’s vomit resembles thick, yellow bile (as opposed to looking foamy like a hairball), she may be suffering from a kidney infection or other kidney-related problem. Other symptoms include changes in appetite, behavioral changes, weight loss, and lethargy. This one requires an immediate trip to the vet, who will check your feline friend’s kidney function and prescribe medication.

A playful calico cat exposing their belly.
pikabum from Pixabay

Intestinal parasites

These diabolical critters, more commonly called worms, don’t always cause symptoms. However, if your cat is losing weight, vomiting, showing signs of bloating, experiencing diarrhea, or suffering from breathing problems, you should take her to the vet to rule out intestinal parasites. 

Psychological issues

Did you know cats can suffer from anxiety and depression just like humans can? If your cat has dealt with stress and upheaval recently, she may react with diarrhea, vomiting, loss of appetite, and weight loss. While major life changes, such as the death of another family member or the addition of a new pet or baby can certainly cause stress, the root cause could be something you would consider minor. Issues like dirty food dishes, loud noises, or food bowls placed too close to a litter box may cause anxiety and depression in your cat. Ensure your fur baby has access to clean bowls, a quiet place to eat and drink, and plenty of space between her bowls and her litter box. If the problem continues, please consult your vet. 

Hyperthyroidism

Thyroid problems stem from tumors (most often benign) located on the thyroid gland. Common symptoms include increased appetite, vomiting, weight loss, diarrhea, increased thirst, increased urination, and even behavioral changes. Thyroid problems usually occur in older cats, but they can happen at any stage of life. If you suspect your cat may have thyroid problems, you’ll need to take her in for a checkup. 

Feline infectious peritonitis (FIP)

Even more than the dreaded c-word, FIP is the worst-case scenario for any cat parent. It’s most common in younger cats, but it can strike at any age. Early symptoms include wasting, sporadic fever, lethargy, and loss of appetite. The specific symptoms of FIP depend on which form it takes: Effusive (also called “wet”) FIP involves difficulty breathing and bloating as fluid accumulates. The symptoms of noneffusive (or “dry”) FIP vary, as different organs may be involved. Vomiting, diarrhea, seizures, and ocular symptoms are all possible. Unfortunately, FIP is incurable and almost always fatal.      

Close-up of a tabby cat sticking their tongue out.
Nennieinszweidrei / Pixabay

Your cat is a part of your family, and you want to ensure she lives a long and happy life. If you’ve recently moved, adopted another pet, or undergone another major life change, it’s possible your cat’s issues are stress-related and will resolve after she’s adjusted. Does your cat vomit her food immediately after eating? Try feeding her smaller portions, and she should stop. In other cases, a trip to the vet is in order. When it comes to your fur baby’s health, “Better safe than sorry” is always our motto.  

Mary Johnson
Contributor
Mary Johnson is a writer and photographer from New Orleans, Louisiana. Her work has been published in PawTracks and…
Is your cat obese? 5 ways to help them slim down
Obesity left unchecked can lead to health problems
An obese tabby cat perched on a red wooden table

World Pet Obesity Week is in the fall, so it's the purrfect chance to get your kitty on a diet to slim down in time. According to a survey conducted by the Association for Pet Obesity Prevention (APOP), roughly 61% of cats and 59% of dogs in the U.S. alone are overweight or obese. While few things are more adorable than a chunky cat, obesity in cats comes with a multitude of health risks.

Have you been wondering if your cat needs to lose a few pounds? We're here to share how you can tell if your cat is obese, the potential health problems caused by cat obesity, and five helpful things you can do to help them lose weight. 
What causes obesity in cats?

Read more
Does your dog drink a lot of water? Here’s when you should be concerned
It's usually just the weather, but you should look for signs of dehydration or excess thirst
A pug drinking water from a sink faucet

Ensuring your furry best friend gets plenty of water is one of the most important parts of being a pet parent. But how much water should your dog drink on a daily basis? Veterinarians claim the general rule of thumb is a simple equation: The majority of dogs require around 1/2 to 1 ounce (about 1/8 of a cup) of water per pound of body weight each day. Don't want to reach for your measuring cup? Make sure your pup has round-the-clock access to clean water, and everything should be fine.

That being said, if your dog empties their water bowl several times a day, or you notice their intake has increased drastically, you should probably keep a close eye on things. If your dog drinks a lot of water, you may be wondering, "Why is my dog always thirsty?" We'll share how to monitor your pup's water intake, the most common reasons your dog may be thirsty, and when you should speak with your vet.

Read more
Husky health: 6 common health problems in Siberian huskies and what to look out for
Here’s what you should know if you’re adopting or bringing home a Siberian husky dog
A Siberian husky's close-up with mouth open, panting

Whether you're considering bringing home a Siberian husky or you're just a fan of this majestic breed, it's important to educate yourself about all aspects of their life, including their health. After all, no dog is invincible when it comes to injury and illness. Even though no one can completely predict what a dog's health will look like in the future, a dog's breed can make them more predisposed to certain conditions. A little bit of knowledge can help owners choose which preventative measures they may want to take, and it can ultimately help keep a dog healthy in the long run.

Huskies may be known as a noisy and athletic Northern breed, but even they are predisposed to a few health concerns. These are the kinds of symptoms husky owners should keep an eye out for because when you know what to look for, you're much more likely to catch it early when it's treatable.

Read more