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

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

Feline Intelligence: How Smart Is Olga?

Hi, I’m Christopher! Read my introduction to learn more about me and my silly Russian Blue cat, Olga. Cats are incredibly intelligent, and...

Can Bird Mites Live on Cats? Vet-Verified Facts & Tips

Bird mites are parasites that feed on the blood of avian hosts. While they can’t survive off of feline blood alone, they can...

Siamese Kittens for Sale in Louisiana: Breeders List 2025

Catster advocates for adopting before shopping, though we fully understand there are many reasons for seeking a breeder. So, we encourage it to...

How to Remove Cat Litter Smell From a Room: 8 Vet-Verified Tips & Tricks

Cat owners love their cats; there’s no denying that. But not one has ever remarked how much they love the smell associated with...

More related

Lemonade Pet Insurance Review 2025: A Detailed Look

Lemonade is one of the most well-known pet insurance companies thanks to their viral advertising campaigns. They also happen to be one of...

7 Shorthair Cat Colors for British, Exotic & Oriental Breeds (With Info & Pictures)

One of the most unique things about shorthair cat breeds is the diverse range of colors and coat patterns they’re available in. While...

Can Cats Eat Mushrooms? Vet-Verified Facts, Risks & FAQ

If you’re cooking a delicious mushroom risotto, you might be surprised to find your cat brushing up against your legs and showing interest...

7 Cat Adoption Myths & the Vet-Reviewed Truths

If you’re considering welcoming a cat into your family from a shelter, you may have a few concerns. You may have heard that...

Keep reading

Do Cats Like Blankets? Vet-Reviewed Feline Behavior Explanation & Safety Tips

Cats are interesting creatures that tend to march to their own beat. It can be tough to get a cat to do something you want them to and to stop doing things that you don’t like. So, if a cat...

kitten playing under a blanket

Are Burmese Cats Hypoallergenic? What You Need To Know!

Since they’re affectionate, playful, and fiercely loyal, the Burmese cat is very easy to love. If you’re an allergy sufferer but would love to share your life with one of these wonderful cats, you’ll be pleased to learn that the...

Closeup Burmese Cat Stands on Gray background

When Are a Cat’s Teenage Years? Vet-Reviewed Facts & Useful Tips

Just like humans, cats go through a stage that tends to correlate with “teenage” behavior. Some of it is cute and funny, and some of it is irritating and frustrating. Fortunately, the cat teenage years are not all bad, and...

Bengal kitten playing

Do Flea Collars Work on Cats? Vet-Approved Facts & FAQ

As much as we love our cats, dealing with fleas can be a huge pain. Flea collars are one method of flea prevention that many pet owners opt for, but do they actually work? The answer is yes, but they...

tortie Oriental cat wearing flea collar

What Are Cats Scared Of? 8 Vet-Reviewed Feline Fears & How to Help 

Cats are highly attuned to their environment and are sticklers for routine. This sensitivity can make them easily startled by certain objects, sounds, and situations, and it all comes down to a cat’s natural instinct for self-preservation and unease surrounding...

scared cat hiding behind the drawer

Do All Cats Knead? Vet-Approved Behavior Explanation

Whether you think it’s adorable or find it utterly annoying, you’ve likely caught your cat kneading at some point. This behavior usually takes place on a soft blanket or your lap, and cat fanatics often refer to it as “making...

white-and-tan-kitten-kneading-on-the-bed

Why Do Cats Stare at Nothing? 4 Possible Reasons

Experienced cat owners know that no matter how much we bond with and learn about our pets, there will always be at least a few behaviors that leave us scratching our heads. Cats have all kinds of quirks ranging from...

Tuxedo cat sitting on the bed

How Soon Can I Get My Cat Spayed After Having Kittens? Vet Approved Recommendations

You might have heard it is the best practice to get your cat spayed as a kitten, but we all know that doesn’t always work out. Sometimes, young cats get pregnant sooner than their owner expects. Or you might take...

Mother-cat-and-new-born-baby-kittens-drinking-milk-from-their-mom-breast