Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Ascites in Cats (Abdominal Fluid Buildup): Our Vet Explains Signs, Causes & Care

Share

cat ultrasound at the vet's clinic

Your feline friend’s round belly is often cute and endearing. While that roundness is typically the result of too many treats (which isn’t great in itself), it can also be the result of ascites, or fluid accumulation in the abdomen. Ascites is a sign of disease and often a serious one. So, if you notice that your cat’s belly is suddenly fuller, rounder, or tighter, especially if you’re seeing other signs, contact your veterinarian immediately.

divider 1 paws

What Is Ascites in Cats?

Every abdomen, feline or otherwise, has a small amount of fluid in it, which helps cushion the organs and maintain business as usual. The amount is kept in check by regular balances in the blood and surrounding tissue. Ascites is the name for when that fluid level exceeds normal limits. The amount of fluid accumulation can be small, only noticeable on imaging, or large, and anyone who saw your cat would notice that something’s wrong.

Ascites isn’t a disease in itself; rather, it’s a sign of many different types of diseases. The fluid that accumulates can be made up of blood, serum, or even urine. It can be incredibly uncomfortable, especially in high amounts, as that extra fluid adds pressure to abdominal organs—most notably, the digestive system—and the diaphragm, sometimes making it hard for a kitty to breathe.

cat having an ultrasound scan at the clinic
Image By: New Africa, Shutterstock

What Are the Signs of Ascites in Cats?

Ascites is a sign in and of itself, but it also has signs of its own. These will differ depending on what’s causing the fluid accumulation and how much fluid is in there. So, cats with ascites may present any of the following:

  • Abdominal swelling
  • Discomfort, especially when lying down
  • Lethargy
  • Decreased appetite
  • Nausea, vomiting
  • Difficulty or labored breathing
  • Coughing

Depending on the cause, you may also see:

  • Pale gums
  • Lack of urine
  • Tires quickly or exercise intolerance
  • Fever
  • Increased drinking/urinating

Seek veterinary advice if you’re concerned about your pet’s well-being.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

What Are the Causes of Ascites in Cats?

A cat’s abdomen doesn’t just randomly decide to start hoarding fluid. But what causes fluid buildup in a cats stomach? Instead, ascites is brought on by many different causes, affecting anything from the blood vessels to the bladder.

  • Trauma: Falls or being hit by a car are common causes of internal bleeding or rupture of the urinary bladder, which can lead to ascites.
  • Heart failure: When the right side of the heart is struggling, it often can’t pump the necessary amount of blood into the lungs, so that blood backs up into the body, enabling fluid to escape into the abdomen.
  • Loss of protein in the blood: Proteins like albumin are needed in the blood to retain fluid in the bloodstream. If those proteins are lost through kidney issues or parasites or not made at all due to liver disease, fluid can escape the bloodstream and congregate in the abdomen.
  • Bladder rupture: Trauma isn’t the only thing that can cause the urinary bladder to rupture; urethral blockage from a stone or blood clot can also do it, causing urine to flood the abdomen.
  • Infection: Infections in the abdomen or its lining (called the peritoneum) can lead to inflammation and the release of fluid from the surrounding tissue. The most famous culprit of this is feline infectious peritonitis.
  • Cancer: Any tumor type or size in the abdomen can lead to ascites in a similar way that infections do, which is inflammation. Tumors may also bleed, making blood accumulate where it shouldn’t, and the tumor itself can contribute to a swollen abdomen if it takes up a large amount of space.
ultrasound of a cat's stomach
Image Credit: Andrii Medvednikov, Shutterstock

How Do I Care for a Cat With Ascites?

There is nothing that you can do at home for a cat with ascites; it’s a veterinarian-only situation. Keep in mind that small amounts of fluid accumulation can go unnoticed, especially to the naked eye, so your cat may have ascites, and you won’t know it without proper imaging. Whether your cat’s belly appears enlarged or not, though, see your veterinarian if you notice any concerning signs.

Veterinary Diagnosis With Ascites

Your vet will first need to find out what is causing the abdominal enlargement. X-rays or ultrasound may be required to determine if it’s true ascites or something else. From there, there are many routes that your vet may take, mainly depending on other signs or findings.

They may investigate the heart if your kitty is also having difficulty exercising or if it doesn’t sound quite right when they listen to their chest through a stethoscope. They may run blood work or do a urinalysis to check protein levels and organ function and see what the urine’s up to. Also, they may try to grab a bit of the abdominal fluid using a syringe, needle, and ultrasound guidance. Analyzing the fluid will tell them what it’s made up of so they can further look into things like infection, cancer, etc.

Veterinary Treatment of Ascites

The main way of reducing fluid accumulation in the abdomen is to correct the cause of it getting there in the first place. That may include antibiotics, heart medications, diuretics, surgery, chemotherapy, or supportive care. Sometimes the cause can’t be fixed, so a vet may decide to periodically drain the fluid to make the kitty more comfortable.

The cause and treatment for the underlying sources of ascites are best handled in the early phases, so be sure to see your vet any time you notice that something is off with your kitty, especially if they have an enlarged abdomen.

veterinarian holding the cat
Image Credit: H_Ko, Shutterstock

divider 1 paws

Frequently Asked Questions (FAQ)

How Long Do Cats Live With Ascites?

Since ascites in cats has many possible causes, so does the amount of time that a cat can live with it. Generally, though, ascites is a sign of various significant diseases that may require lifelong treatment, are costly to treat, or have no treatment.

Does Ascites Mean End-Stage?

Developing ascites isn’t a good thing. It’s usually the result of a major health malfunction, such as cancer or heart failure. Catching the issues early can help your cat get proper treatment so they can have a longer and higher-quality life, but many of the health issues that lead to ascites are quite serious.

What Happens If Ascites Isn’t Drained?

The first approach to getting rid of ascites is to treat the underlying condition. Once it’s properly managed, the fluid will often decrease on its own. In cases where a vet chooses to drain the fluid, they do so to make a kitty more comfortable. The more fluid that accumulates, the more discomfort the cat can feel. It can create enough pressure that it’s difficult to breathe, eat, or lie down.

cat examined by Vets
Image Credit: Kzenon, Shutterstock

divider 1 paws

Conclusion

Fluid accumulation, or ascites in cats, is not a normal thing for your pet to experience. It can be a sign of various serious issues, including cancer, heart failure, or an infection. If you notice a change in the size, shape, or firmness of your cat’s belly, especially if they are showing other signs of not eating, difficulty breathing, or lethargy, see your vet immediately.


Featured Image Credit: Libre, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

2 Responses

  1. Dear Doc,
    my maine coon was well and happy. suddenly one day he had this swollen abdimen when the day before he was very well. thereafter it became worse and he lost tremendous weight. all tests were done even for FIP which was negative. Finally had his abdo drained several times and the Vet said she did not want to do this again as it was only prolonging my cats condition. i had to put him to sleep which I still cannot get over. how can a cat get fluid build up from one day to the next? suddenly?

    1. Hi Della, sorry to hear about your cat’s ascites. It sounds like you are looking to speak with a veterinarian about your cat’s case. Our vets at www.pangovet.com would be happy to assist you, answer your questions, and guide you through the best next steps.

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Why Healthy Cats Still Vomit Sometimes (And How to Respond)

A cat that just vomited needs a specific kind of care, and the feeding decisions you make in the next few hours actually...

Scientists May Have Found the Missing Piece in Feline Kidney Disease

One of the most upsetting parts of caring for an elderly cat is the knowledge that there is a very high chance that...

Ask Dr. Paola – Help! I Am Worried My Cat Isn’t Getting Enough Water! (April 6, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

The 10 Common Causes of Sudden Death in Cats (And Which Ones Are Preventable)

Most cat owners don’t think much about heart disease, internal hemorrhage, or viral infections until they’re staring at an empty bed. Sudden death...

More related

Do Cats Think Humans Are Cute? Exploring Feline Social Perception

Cats are absolutely adorable, and there’s even scientific proof that kittens are biologically designed to be cute and capture our attention.1 There’s no...

9 Best Medication for Cat Allergies (2026) – Reviews & Top Picks

Allergies occur when the immune system is sensitive to a particular substance. The allergens may not affect your other pets, you, or human...

Do Neutered Cats Spray? Vet-Reviewed Behavior

Cats are wonderful companions, but they do exhibit some quirks that must be dealt with accordingly. One common problem among cat-owning households is...

How Do Cats Drink Water? Vet-Approved Facts

Have you ever watched a cat drink water before? It’s not something many people think too much about, but it’s truly an amazing...

Keep reading

Evolve Cat Food Review of 2026 : Recalls, Pros & Cons

Review Summary Crafted with premium, whole-food ingredients, Evolve cat food contains exactly the nutrition your feline needs to stay in peak health. It’s a bit pricey, but you’re getting quality recipes for what you pay. Granted, not all cats love...

Evolve Cat Food Review

Why Do Cats Like Hiding in Dark Places? 5 Vet-Reviewed Reasons

Cats love to hide behind furniture, in boxes, and under just about any object they can fit beneath. They are so stealthy you may find yourself shaking a bag of treats just to ensure they’re still in your house! But...

cat hiding in a dark place

How to Tell if My Cat Needs Their Glands Expressed? 6 Vet-Verified Signs

As a cat owner, you need to make sure your beloved friend is healthy, and sometimes that means dealing with bodily functions that aren’t so pleasant. Cats have two anal sacs that help them mark their territory. The sacs are...

Cat sitting on a vet metal table

Can Cats Eat Parmesan? Vet-Approved Nutritional Facts & FAQ

As a cat owner, you know how tough it can be to say “no” to your kitty begging for a taste of food off your plate at the dinner table. Some human foods are okay to offer your kitty in...

Can Cats Eat Parmesan

Can Cats Eat Jalapeños? Vet-Reviewed Facts & FAQ

Jalapeños are tasty, spicy peppers that people enjoy in a variety of dishes and are prepared in lots of different ways, such as raw, sauteed, and pickled. These peppers may be an enjoyable food item for people, but what about...

Can Cats Eat Jalapeños

Can Cats Eat Pig Ears? Vet-Approved Facts & FAQ

Cats are carnivores and require diets rich in protein from animal sources to thrive. Although pork is fine for cats to eat, and pig ears aren’t toxic for cats, pig ears aren’t made for cats, and can damage their teeth,...

Can Cats Eat Pig Ears

Why Do Cats Like Their Butt Patted? 7 Vet-Reviewed Reasons

No matter how much we love them, no one can deny that cats can do strange things. They are daredevils that enjoy high places. They fixate on the smallest things and can sit there for hours, seemingly staring at nothing....

cat wearing fabric collar looking camera and lying on the pillow when owner hand patting back

How to Handle Food Aggression in Cats: 11 Vet-Reviewed Tips & Tricks

Dealing with food aggression in a cat can be overwhelming and even scary at times. Food aggression can exhibit itself in a variety of ways, including growling, biting, food stealing, and attacking. Unfortunately, without appropriate management, food aggression will almost...

tabby cat eating cat food out of bowl inside

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.