Stinky Breath: Why Does My Cat's Breath Stink and Is It Normal?

Author: K. Marie Altoby K Marie Alto Updated 11 min read

Stinky Breath: Why Does My Cat's Breath Stink and Is It Normal?

There's a stereotype for most pets that they love to get up in our faces, but they have horrible breath. Cats 🐱 are no exception to this, though they may not be as up-front about it as dogs.

The question is, is bad breath normal for cats, or is it a sign of something you should be concerned about?

Today we’re going to talk about many of the causes of bad cat breath, whether this is considered normal, and what you can do to help your furry friend.

As always, if you are looking for research-backed 📚 cat care guides you can actually trust, feel free to visit my blog and search by topic. I’m sure you'll learn a thing or two that will improve your cat’s life.

As usual I’ve added a great educational short video 📽️ by The College of Veterinary Medicine at Cornell University on how to easily train your cat to let you brush their teeth. This is a must-watch!

Is Bad Breath Normal for Cats?

No, bad breath is not normal for cats no matter their age. Just like with us humans, while you should not expect a floral bouquet scent coming out of your kitty’s mouth, an offensive stinky mouth is never normal, never.

Cat With Bad Breath Image by Toe Beans

Interestingly, many people think bad breath on a dog or cat is normal, because the fact is most fur babies that you encounter have bad breath. So, while it might be common, bad breath is not normal.

"A healthy cat's breath should not be offensive." - Eric Davis, DVM, Cornell University's College of Veterinary Medicine.

A cat lying on a bed biting a cat toy by Momma Knows Best Organics

Read More Cat Health Care Guides

There's a level of bad breath that goes beyond just "what they ate," and that's where bad breath can get a little concerning for cats. Felines with persistent bad breath likely have another underlying condition going on.

Causes for Bad Breath in Cats

There are levels of bad breath, and if you don’t brush your kitty’s teeth you are likely familiar with their normal breath smell.

But if your cat suddenly gets bad breath, like, worse than their normal breath, it's worth identifying the cause to help remediate the underlying problem.

1. Bad Diet

First of all, a bad diet can cause bad breath.

This happens a lot when you're feeding your fur baby the cheapest food you can get them to eat.

A Cat Eating Image by Toe Beans

No judgment here; sometimes we do what we have to when times are tough. But food that is full of additives and stuff your cat can't digest will have systemic effects.

They'll have trouble digesting it, and some of the ingredients they can break down will decompose or digest into nasty bacteria and other chemicals that can cause stomach problems, organ problems, and, you guessed it, bad breath.

Read More Cat Health Care Guides

Catnip Cat toys by Momma Knows Best

It’s also worth noting since cheaper food has lower quality ingredients, in addition to making your cat’s breath stinky, it also often causes stinkier poop and more of it.

2. Fish Burps

A similar diet-related cause of bad breath is fish (in dogs, too). Cats love fish, and I mean love fish.

You might be surprised to find fish included in “chicken” recipes. So, while you might not be feeding your kitty a “tempting tuna” flavored cat food, check out the label to see if fish is hidden in the ingredients.

A Cat With Fish Image by Toe Beans

If you've ever taken a fish oil pill and had "fish burps," you know how that scent comes back up in a worse form than it went down.

This happens just the same when your kitty is eating something fishy. So, if they have breath that smells like fish that was left out in the sun a little too long, this could be the cause.

3. Gingivitis

Gingivitis is the swelling and inflammation of the gums.

Vet Checking Cat For Gingivitis Image by Toe Beans

Gingivitis is caused by a buildup of plaque, which is basically bacteria that when left alone forms into a hardened substance called tartar.

Unfortunately, this stuff smells pretty bad. Part of dental cleaning is scraping off this plaque before it hardens into tartar and becomes much harder to get rid of.

Since your cat isn't brushing their little teefers every day, they suffer from a lot more of this build-up than we generally do, but we’ll talk more about teeth brushing later.

Aside from bad breath, there are several other signs that may indicate your kitty has gingivitis. It’s important to identify and treat gingivitis early as it can lead to a more serious condition, which we’ll discuss next.

Read More Cat Health Care Guides

Gentle Cat Brushes_ by EarthCare

But first, it’s important to know that gingivitis is a preventable, but also treatable condition.

“Given adequate plaque control and thorough, consistent dental home care, gingivitis is a reversible and controllable condition.” - Journal of feline medicine and surgery

4. Periodontal Disease

By far, the most common cause of bad breath in both people and in cats is periodontal disease. This is a fancy term used to describe infection and inflammation of the gums, ligaments, and bone.

Vet Checking Cat For Periodontal Disease Image by Toe Beans

Periodontal disease starts off as gingivitis, which is why you’ll want to nip the problem in the bud before it progresses. With all the tartar build up and infection in the mouth as you may imagine your kitty’s breath will be quite smelly.

Periodontal disease has to be treated by your veterinarian with a thorough cleaning of your cat’s teeth. Depending on the amount of damage s/he may also require dental extractions.

5. Stomatitis

Stomatitis is another form of inflammation, and while it can include the gums, it’s more severe than gingivitis as the entire mouth can be inflamed.

Specifically, stomatitis is a swelling and inflammation of the mucous membranes and other areas around the mouth. Gums, tongue, cheeks, it all gets swollen and can rub into open sores. All of this is painful and irritating, and worse, vets aren't even sure what causes it in cats.

Vet Checking a Cat For Stomatitis Image by Toe Beans

Also known as Feline Chronic Gingivostomatitis (FCGS), cat stomatitis affects about 0.7-4% of cats.

Unlike gingivitis or periodontal disease, stomatitis is very hard to handle at home and will require treatment by your vet. In the meantime, your cat will have a hard time eating, grooming, and generally using their mouth for anything.

There's also a related kind of stomatitis called Lymphocytic Plasmocytic Stomatitis. It's the same effect but with a different cause; vets believe it's related to feline leukemia, FIV, calicivirus, or bartonella. It's relatively rare but very extreme, so it needs to be diagnosed and treated as soon as possible.

Read More Cat Health Care Guides

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6. Diabetes

"Bad breath" can come in many different forms. While it might not be pleasant to you, giving that breath a second sniff can give you a few clues as to what might be causing it. Specifically, this and the next few entries on this list all have more characteristic smells.

Treating a Cat For Diabetes Image by Toe Beans

If their breath is bad, but it smells slightly sweet (or even very sweet), then it could be a sign of diabetes mellitus.

This is an issue with the pancreas and is pretty similar to diabetes in people. It's just an issue with the body's ability to produce insulin, which can have pretty severe consequences if left untreated.

Cat cave cat beds by Toe Beans_2

You may want to change your cat's diet to one that is diabetes-friendly in addition to talking about treatment options with your vet.

When it comes to diabetes, bad breath likely isn’t the first sign you’ll notice though. Pet parents usually notice increased thirst and urination.

7. Kidney Disease

Another issue that can be partially identified through the breath is kidney disease. Kidney disease is extremely common in older cats and one telltale sign is an ammonia smell on the breath.

Vet Checking a Cat For Kidney Disease Image by Toe Beans

The kidneys are responsible for filtering waste from the blood and expelling it, primarily through urine; if they aren't working, the stuff that makes urine smell the way it does isn't expelled, so it builds up and can express itself through things like the breath.

Kidney disease is progressive, so it’s good to have routine bloodwork done to identify it early, so you can make adjustments as needed.

Cat books by toe beans

If you smell an ammonia-like bad breath on your fur baby's breath, you should consult with your vet.

8. Other Issues

There are other possible causes of bad breath as well.

A Cat With Bad Breath Image by Toe Beans

These can include:

  • Oral cancers causing various bacterial and other problems in the mouth.
  • Localized infections in the mouth, usually because of a cut or scrape.
  • Rotting teeth, which is an advanced form of periodontal disease and requires dental surgery.
  • Liver Disease, which can cause the breath to smell a bit like ammonia.
  • Gastric reflux, where the acid in the stomach works its way back up the throat, with all that entails.
  • Intestinal blockages, which can lead to the breath smelling a bit like feces.
  • Coprophagia – common in dogs, less so in cats – where the cat eats the feces, which can lead to that smell on the breath.

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All of these are potentially dangerous causes. While not all bad breath is a sign of an impending crisis, many of them need to be addressed as soon as possible, so it's generally a good idea to give your vet a call when your kitty’s breath starts turning bad.

How to Help Treat Bad Breath in Cats

While many of the causes of bad breath in cats aren't things you can handle at home, some of them are, and others are preventable.

Look At Your Cat's Diet

First and foremost, you want to look at your kitty's diet. The worse the food they're eating, particularly in terms of additives, the more likely they are to end up with issues because of it.

There's a lot of debate over what the best diet is, and some cats have particular preferences when it comes to food, but really a lot of it just comes down to feeding them healthy carnivore ingredients.

The more fillers and non-carnivore foods you feed them, the worse off they're going to be. If you decide to change your cat's food, make sure you transition them to the new diet carefully.

Brush Their Teeth

The other thing you can do at home, and it can have a huge impact, is brush their teeth.

Brushing a Cat's Teeth Image by Toe Beans

Yes, that's right; a little kitty toothbrush and some kitty-safe toothpaste (or gel, rather) can go a long way.

Most parents tend to think of brushing their cat’s teeth as mission impossible. In reality, and just like with almost everything related to your cat, it is less difficult than you may think. The key is in successfully completing a training program.

I’m not going to lie to you, it’s going to take some time, some patience and above all a lot of love. But the upside is that your cat will thank you with many healthy smiles, fresh breath kisses and much better overall health. Remember this, a healthy kitty is a happy kitty, and happy kitties make happy cat parents 😊. And I speak from experience…a lot of it.

Of course, your cat probably doesn't want you mucking about in their mouth, so you're going to have to train them to tolerate it. Starting young is the best option, so they can learn to tolerate it early, and you won't have troubles later in life.

How Can I Train My Cat to Let Me Brush Their Teeth?

Start by using a finger (with a protective barrier or not, depending on how bitey your fur baby is) and just gently pull back their lips and dab a bit of tooth gel on their teeth.

You don't need to rub or jam your finger in their mouth, and you shouldn't try to pry their jaw open, either. Just get them used to the idea and experience.

The key is to reward them after you do this with a high-value treat. Depending on the cat, this could be a bit of prized soft food, a drink from a running faucet, or another treat you know they love.

Once they're more tolerant, you can start to use a brush instead of a finger. Similarly, as they grow more used to it, you can do a bit more aggressive brushing.

Your goal is to get them to the point where they tolerate daily tooth brushing, even if it's cursory. Even a little bit is better than nothing.

Because it’s such an important topic, we’ve written an entire post about how to brush your cat’s teeth, so check it out for more info.

Check out this 3.5-minute video about a 4-week plan to train your cat to let you brush their teeth by The College of Veterinary Medicine at Cornell University.

Stinky Kitten Breath vs Stinky Cat Breath

While it may be surprising to imagine that your tiny, adorable kitten could possibly have foul-smelling breath, there are several reasons why this can occur.

Kitten Breath

It's important to note that while some causes of bad breath can be expected in kittens, persistent or severe halitosis should be evaluated by a veterinarian.

  • One common reason for bad breath in kittens is dental issues. Just like with our grown up fur babies, kittens can develop plaque, tartar, and gum disease, leading to bacterial growth and an unpleasant odor. The teething process can also contribute to bad breath, as inflamed gums and the eruption of new kitty teeth may create an environment for bacterial growth.
  • Diet can also play a role in a kitten's stinky breath. Some commercially available kitten foods or treats may contain ingredients that can cause oral odor. Dietary changes or an unbalanced diet can also lead to digestive disturbances.
  • Mostly, though, kittens are naturally curious and may explore their environment by chewing on objects they shouldn't. Ingesting foreign objects or substances can cause gastrointestinal problems, leading to bad breath. It's important to kitten-proof your home as best as you can and keep trash, certain types of poisonous houseplants, and other dangerous items out of their reach.
  • Kittens may also have a higher incidence of parasitic infestations than adult fur babies. Certain parasites, such as giardia or roundworms, can cause gastrointestinal symptoms and contribute to foul-smelling breath. When kittens are young, they are more susceptible to these things, and some of them happen to cause the stinky breath you're experiencing.

While bad breath can be expected to some extent in your little furballs, it's essential to differentiate between temporary issues and persistent halitosis that may indicate an underlying health problem.

Regular dental care, such as brushing the kitten's teeth with a veterinarian-approved toothpaste, can help maintain oral health. Feeding a balanced, high-quality diet and providing appropriate toys can also promote oral hygiene and reduce the risk of bad breath.

When to Take Your Cat to the Vet

At a minimum, your cat should have regular check-ups to evaluate their health, and those appointments should include oral inspections.

On top of that, you will want to take them to the vet if they suddenly develop extremely bad breath, particularly if that foulness smells like ammonia or smells sweet.

If it only lasts a day or two, don't worry about it. Otherwise, at the very least, you should call your vet and see what they have to say.

Vet Examining Cat's Oral Health Image by Toe Beans

Luckily, many issues that cause bad breath can be caught and treated early when you notice them and get the proper care. It's only when you accept bad breath as a fact of life and let the underlying cause fester that it can become a dangerous issue.

Do what you can to care for your fur baby's mouth, evaluate their diet, and make sure they get regular check-ups for the best possible chances of keeping them healthy.

Do you have any other questions about cat mouths or bad breath or anything else? If I didn't answer your question, let me know in the comments, and I'll do what I can to respond!

K Marie Alto
K Marie Alto

K. Marie is an animal lover, wife, kitty mom, dog auntie, writer, and co-founder of Toe Beans, a proud American family-owned online boutique pet supplies store focused on the improvement of the life of furry family members via pet parent education, better products, and advocacy. She has over 20 years of experience as a pet momma. She loves sharing her personal journey and experience as a pet parent via her blog and Facebook page where she currently has more than 50K followers (@furrytoebeans) and counting :-). Read more

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