Gas in Cats: Causes, Symptoms & Cure – Catmart
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Gas in Cats: Causes, Symptoms & Cure

Do you have a cat with awful gas? We’ve all been there. But what causes gas in cats, what symptoms can you expect to see, and crucially—how do you get rid of it?

Is it normal for cats to fart a lot? Some cats fart frequently. When bacteria break down food in the gut, they produce gas, which becomes farts or burps. Some air is also ingested during the normal eating process. Some gas is unavoidable. However, cats can experience severe, painful and inconvenient gas because of incorrect diet and digestive issues. The symptoms of gas in cats include a pungent, eggy smell, bloated belly, and occasionally co-symptoms like diarrhea. Gas can be cured by fixing whatever causes it, e.g. bad diet, worms, hairballs, etc. If the symptoms are severe and persist, simethicone may help. Talk to your vet before giving your cat any medication.

The guide below is divided into several sections. After addressing the question of whether it’s normal for cats to fart a lot or not, it divides the subject into three: the causes of gas in cats, the symptoms that appear alongside gas, and an assessment of various cat gas remedies and fixes.

Do Cats Fart?

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Incorrect diet can make a cat fart much more than normal.

Cats fart, just like all mammals fart. If you’ve never experienced cat flatulence first hand (or first nose…) consider yourself lucky.

Gas occurs when food is broken down by the stomach and gut, and when air is swallowed during eating. This gas and/or air has to find a way to escape, and it can either come from the mouth as a burp, or the behind as a fart.

Gassiness varies between cats. Some cats fart very infrequently, while others seem to fart all the time.

Is It Normal for Cats to Fart a Lot?

It can be a sign of good health for your cat to fart a lot. As it is a function of normal digestion, gas shows that digestion is working normally! It can also be a sign of bad health: it can occur alongside diarrhea, for example, or because of a bad diet.

In that respect, cat-farting is much the same as people-farting. It can be normal, or it can be bad. As such, don’t assume that just because your cat is farting, that there’s something wrong with it; or, that just because farting is often benign, it cannot also be a sign of poor health.

Why Does My Cat’s Fart Smell So Bad?

Cats are obligate carnivores. That means they should only eat meat. Cats can survive on foods other than meat, but the ideal cat diet doesn’t contain fruits, vegetables, grains, or any of the many things people eat. While farts can smell no matter what diet the farter eats, meaty farts can smell particularly bad. That’s because fatty meats contain lots of an amino acid called methionine. Amino acids are the building blocks that proteins are made from, and are an essential part of any diet. Unfortunately, methionine contains lots of sulfur, so when your cat’s gut breaks it down, horrific sulfurous farts are the result. If you notice that your cat’s farts smell like rotten eggs, then that’s the likely reason why.

Besides that, your cat may need to go to the toilet soon. Gas often comes before your cat goes to the toilet. That’s because your cat’s guts are working to move its poop to ‘the end of the line’, and gas is brought along with it. It might be disgusting to think about, but because the gas has to pass through and around stool to ‘exit’, that makes it smell more.

Gas also tends to smell worse when it’s produced by bacteria than when it’s air that has been swallowed. It’s the breaking down of amino acids like methionine that produce the distinctive farty, eggy smell you’re familiar with; the less swallowed air is mixed into that gas, the worse the fart will smell.

What Causes Gas in Cats?

Gas has many causes, which makes it a complicated problem to fix. Below are the most common reasons why gas occurs; check each to see which might apply to your cat, and remember that there may be more than one cause at play.

1) Does Diet Cause Gas in Cats?

Gas is a very natural by-product of the digestive system. You may not like the way it smells, but it can be a sign of good health, not just bad.

Let’s start off by understanding what gas fundamentally is. Gas is a gas, in the sense of ‘solid, liquid and gas’, that’s trapped in the digestive system. It can be let out from either end. What that gas is depends on what caused it, but healthy gas occurs when bacteria break down food. When bacteria process the sugars in your cat’s food, they give off small amounts of gas (hydrogen, carbon dioxide, and methane). There are trillions of bacteria in your cat’s digestive tract, and each produces a very small amount of gas as it ‘eats’. This accumulates until the pressure of the gas forces its way out… One way or another.

2) Cat Gas Stinks, So Is Noticeable

Your cat may not be farting an unusual amount. You may just be noticing its farts because they stink so bad. Cat farts are on a par with dog farts in how bad they smell.

As such, what may be happening is that you notice Every. Single. One. of your cat’s farts just because they smell so bad. Your other pets (or partner, or children—delete as applicable) may fart just as much as your cat, or maybe even you do. But some of these farts will be smellier than others, and some might not smell at all, so you might not notice them.

It’s also possible for your cat’s farts to be temporarily smellier than usual. This could give the impression that your cat has suddenly started farting, even though in reality, it always has done.

3) Eating Too Fast Causes Gas in Cats

Another benign cause of gas is when your cat eats too fast.

So, the main way in which gas enters the digestive tract is when bacteria break down food. But it’s also possible to swallow air; that means the air doesn’t go down into your cat’s lungs, but into its stomach by accident. Cats are especially susceptible to this because they struggle to chew food as well as we can, due to their sharper teeth.

Air that enters the stomach can be belched out easily, but it isn’t always. If it’s processed along with the food in the stomach, it enters the gut, and carries on up the gut until it becomes a fart. With the gas that the bacteria in your cat’s gut are producing, this causes lots and lots of gas to build up.

4) Bad Diet Causes Gas, Too

But gas isn’t exclusively a sign of good health. It can be a sign of bad health, too; in this case, bad diet.

If you’re intolerant to any kind of food, you’ll be familiar with how it can cause gas. Even minute amounts of a food you’re intolerant to can trigger painful, long-lasting gas; the same can happen to your cat. The reason for this is that your cat’s digestive tract struggles to break down certain foods, which can cause more gas than usual.

Housecats typically don’t have the ideal diet. Cats should eat nothing but meat, but eat foods that contain lots of grains, beans and dairy. Foods like these can cause gas or make gas smell worse:

  • Grains and beans contain lots of carbohydrates. Carbohydrates, particularly sugars, break down quickly and so produce lots of gas.
  • Cats shouldn’t eat or drink dairy foods. Like all mammals, once they grow into adulthood, they stop drinking milk. The only animal on earth that keeps drinking milk once it grows up is sitting in your computer chair…!

Feeding your cat something unsuitable can cause temporary gas. It can also cause permanent gas, provided that you continue to offer the unsuitable food.

Cats can also dig around in bins in search of food. When they do, they might find food that’s gone bad, or that’s unsuitable for them. So, even if you do feed your cat a healthy diet, it might still find food that’s bad for it elsewhere.

5) Bad Digestive Health Causes Gas in Cats

Don’t immediately jump to the worst possible conclusion… But gas in cats can be a sign of wider health issues. Some of them are quite serious. In no particular order, gas can be associated with:

  • Tumors. Tumors cause the belly to swell, and give the appearance of gas. They can also put physical pressure on the digestive system and encourage gas to develop and escape.
  • Inflammatory bowel disease. Inflammatory bowel disease is a syndrome, wherein your cat’s gut stops working properly. It occurs as part of a specific reaction in your cat’s gut to chronic irritation. The gut then becomes inflammed, which stops it from absorbing nutrients as it should. This can make gas worse.
  • Physical obstructions. These block gas from passing correctly.
  • Intestinal viruses. Viruses can cause inflammatory bowel disease, and can also contribute to gas.

These problems require health care outside of the context of their causing gas.

6) Can Worms Cause Gas in Cats?

Worms can cause gas in cats, too. Roundworms can cause severe digestive upset, one symptom of which is the creation of excess gas.

7) Can Hairballs Cause Gas in Cats?

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Hairballs, among other things, cause gas.

Hairballs don’t cause gas per se, but they can make gas more unpredictable and noticeable.

Hairballs famously cause blockages in your cat’s intestinal tract. They occur when the fur that your cat ingests during grooming balls up and can’t escape from the stomach. Individual hairs typically make their way all the way through your cat’s gut, but some get stuck for whatever reason, and clump up. Hairballs are typically coughed up, but can also travel through the gut to be pooped out.

When this happens, both gas and stool can struggle to get past them. This causes the familiar bloating of gas. Your cat isn’t necessarily producing more gas than usual, it’s just that the gas can’t pass easily, so accumulates. It will gradually be released, unless the blockage is complete, in which case the issue is a medical emergency.

8) Why Does My Cat Fart When I Pick Him Up?

Here’s another simple reason why cats might fart. Have you ever noticed that when you pick up your cat, it immediately lets out a silent-but-deadly fart? You could be forgiven for thinking that this is some kind of defense mechanism, but it’s not.

The reason cats do this is that pressure applied to the stomach and gut can help gas along the digestive tract, easing its passage and helping it ‘escape’. If you’ve ever had bad gas that just won’t come out, you’ve probably rubbed or kneaded your gut to try and physically push it along. Well, you can do the same to your cat.

9) Why Does My Kitten Fart So Much?

Kittens can fart because of all the reasons listed above: bad diet, hairballs, worms, inflammatory bowel disease, eating too fast, or as a regular side effect of digestion.

But kittens also have to transition from a milk-based diet to a fully-weaned, solid food diet, and this can exacerbate gas problems. It takes time for any animal to get used to new food, be that you or your cat. When your kitten starts eating solid foods for the first time, its gut goes into overdrive trying to figure out what’s going on, and how to digest this new food. Because it’s not yet effective at digesting these foods, excess gas can result.

This normally clears up on its own as your kitten’s digestive flora catch up with its diet. Milk-digesting bacteria will become less common, while meat-digesting bacteria become more common, meaning your kitty can better handle its new diet. But until then it will be gassy!

10) Some Cats Just Like Farting

Owner experience suggests that some cats simply fart more than others, for reasons that must forever remain a mystery. Your cat’s gut may not be as efficient as the gut of another cat, for example, so will have trouble digesting a diet that another cat might be fine on. Or, its gut may be prone to blockages, and so gas builds up over time.

Symptoms of Excessive Gas in Cats

Gas can either be a problem on its own, or a symptom of an underlying health issue. When gas is just gas, there are, shall we say, obvious signs—it stinks. But when gas is a part of a wider digestive problem, there are other symptoms you may notice which are also considered here.


Cats’ farts smell, just like any other fart. If you’ve ever had a dog, and smelled what a dog’s fart smells like, it’s not too dissimilar to that. Pet farts smell like particularly bad people farts. This smell can linger for a long time, especially if you don’t have much air circulation!

My Cat Has a Bloated Belly

‘Bloating’ is something of a catch-all term. It can refer to bloating from gas, or bloating from having too much salt in the diet, or too much water. It can also be a symptom of other health conditions, like liver disease. In this context, however, the bloating occurs because of gas.

The gas physically takes up space in your cat’s gut, just like a balloon filled with air will expand. You can physically feel that your cat’s belly is bigger than usual. It may feel slightly expanded, or even taut, again like a balloon (in the case of very severe gas).

Bear in mind, though, that bloating isn’t only associated with gas. It can also occur because of much more serious conditions, such as tumors. As such, if your cat’s belly is bloated and you don’t know why, you should take it to the vet.

Cat Has Gas AND Loose Stools

Gas is a symptom in itself of other health conditions. As such, it can appear alongside diarrhea.

Roundworm infestation is a good example. Roundworms cause generic digestive upset, one symptom of which is diarrhea, and one symptom of which is gas. They also contribute to the mass of the abdomen, so in severe cases of infestation, can make the belly bigger too (giving the characteristic bloated appearance of gas). If worms are the cause, then you will notice them in your cat’s stool. Similarly, you may notice your cat vomiting or regurgitating; not caused by gas, but related to it.

How to Treat Flatulence in Cats

If your cat keeps farting, you should try to understand why, and fix whatever’s causing the problem. This section is all about how to do that.

Talk To a Vet

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Your cat may not love their vet as much as they love you, but the vet always has their best interests at heart! Image courtesy of the US Air Force

There is no replacement for a vet’s care and advice. Your vet can diagnose your cat’s health issue and adminster the correct cure for it.

This is particularly important in the case of gas, because there are so many things that could be causing it. There’s no point treating your cat for hairballs, for example, if the problem actually causing your cat’s gas is its diet. The vet can tell you exactly what’s wrong. Besides that, it’s possible for you to diagnose gas when the problem is actually something much more serious, like a tumor. Tumors can cause big distended bellies in the same way that gas can, but, of course, are much worse for your cat. If you fiddle around trying to cure your cat’s ‘gas’ when it’s actually seriously sick, it could pass away.

To diagnose your cat’s gas, the vet will take two approaches. The first is that they will ask you about your cat’s diet and lifestyle, just in case there are any obvious causes (e.g. you feed your cat nothing but bread!) The second is that they will perform a physical exam. They will look your cat over, feel it in certain places (palpation), and perhaps use medical tools to diagnose the presence of gas. They can then recommend a way of fixing the problem. That could be:

  • Worming tablets to get rid of worms
  • A dietary change
  • Treatment for irritated bowel
  • Treatment for hairballs
  • A combination of the above

It’s wise to follow the vet’s advice, whatever they recommend.

Best Cat Food for Gassy Cats

As well as addressing the symptoms, you should address the underlying cause. The cause of your cat’s gas may be its diet, so you should assess what it eats and consider whether you can feed it something better.

In particular, check your cat’s food for grains and beans. Wild cats don’t eat these things. To be clear, your cat can both survive and thrive with these foods supplemented as a part of its diet; but they can cause bad gas. So, if your cat’s gas is bad enough that you have to take drastic steps to correct it, switch your pet to a higher-quality diet. An all-meat diet, a raw meat diet, or even a diet with less grains and carbs in it would help.

When you switch your cat to a new diet, no matter why you do so, do so as slowly as possible. This will give your cat’s gut time to adjust to its new diet (like the kitten described in the section above). If you don’t do this, then your cat’s unfamiliarity with its new diet could, in itself, cause gas. You could be forgiven for thinking that it isn’t better, when in fact it is. Follow the 20% rule: change out 20% of your cat’s old diet for its new diet each week, either by weight or by mealtimes (e.g. four old meals, one new meal). Then, next week, up the proportion of new food (three old meals, two new meals). Continue until your cat has fully switched to its new diet.

Cat Gas Remedy

It’s not typically recommended to treat cat gas with some kind of medicine. That’s because there is almost always an underlying cause that you should fix instead.

Let’s imagine a cat called Tabby. Tabby eats a diet full of grains and has a worm problem. These two problems combine to cause Tabby lots of gas. Tabby’s owner knows of a couple different kinds of medicine she can give to her, and lo and behold, they work: Tabby starts farting a little less. The problem is that she’s still eating a bad diet, and she still has worms. The moment she stops taking the medication, the gas will come back. That’s not to mention the other side effects of worms and bad diet.

If your cat has problems with gas, simethicone is the best medication. Simethicone is an anti-foaming agent that helps reduce bloating, discomfort and pain that results from gas. It works by allowing the gas bubbles in the gut to come together more easily; it breaks down the bubbly boundaries between them, so that they can form larger bubbles of gas. These are more easily passed through the gut, effectively getting rid of all the gas at once.

There are brands of simethicone that are manufactured for pets. Gas-X is perhaps the most common, but it’s not the only one. According to PetPlace, other brands include:

  • Alamag Plus® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Aldroxicon® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Almacone® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Balanta® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Dixlanta® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Flatulex® Tablets (containing Activated Charcoal, Simethicone)
  • Gelusil® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Gen-Lanta (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Imodium® Advanced (containing Loperamide, Simethicone)
  • Losospan® Plus (containing Magaldrate, Simethicone)
  • Low Sodium Plus® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Lowsium Plus® (containing Magaldrate, Simethicone)
  • Maalox® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Magaant® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Magagel® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Magaldrate Plus (containing Magaldrate, Simethicone)
  • Magalox® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Maldroxal® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Masanti® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Mygel® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Mylagel® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Mylagen® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Mylanta® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Ri-Gel II® (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Ri-Mox® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Riopan® (containing Magaldrate, Simethicone)
  • Rolaids® Multi-Symptom (containing Calcium Carbonate, Magnesium Hydroxide, Simethicone)
  • Rolaids® Plus Gas Relief (containing Calcium Carbonate, Simethicone)
  • Rulox® Plus (containing Aluminum Hydroxide, Magnesium Hydroxide, Simethicone)
  • Titralac® Plus (containing Calcium Carbonate, Simethicone)

As you’ll no doubt have noticed, these are combination medications that contain more than one kind of medicine. The medicines aside from simethicone have similar beneficial effects. Aluminum hydroxide, for example, is used to treat heartburn. Always talk to your vet before giving your cat any medication.

What to Do If Your Cat KEEPS Farting

If your cat continues to experience severe gas despite the changes you’ve made, consider taking it back to the vet. The vet’s initial diagnosis may have been incorrect, or there may be multiple causes of gas that weren’t identified. Further veterinary assistance may fix the problem.

However, your cat will fart no matter what you do. Gas is a natural by-product of digestion, so while it might stink, it’s perfectly healthy. You can therefore never completely stop your cat from farting.

Hi! My name is Jamie Fallon. I run Catmart, an online cat health and cat behavior resource. If I'm not sat in front of my PC—and I usually am—then I'm either spending time with my cats or my other half... Whoever jumps on me or asks me for food first!

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