Does your cat's breath smell? It could be a sign of illness

2 August 2023 - 6 min read

The information in this article has been reviewed by Kirsten Ronngren DVM MRCVS on 31 July 2023 . Although it may provide helpful guidance, it should not be substituted for professional veterinary advice.

Man in white t-shirt brushing cute blue Abyssinian cat's teeth at home high res

If you spend enough time up close and personal with your beloved kitty, you’re bound to get a whiff of their breath every once in a while. While you can’t expect it to smell like a fragrant summer meadow, a foul or sudden change in smell should prompt an immediate trip to the vet.

In fact, this might be a symptom of a serious health condition. Bad breath in cats, also known as halitosis, can result from diet, an internal illness, dental or gum disease, or other oral health conditions.

So if your cat’s breath suddenly starts to smell, you should take them to the vet as soon as you can. Your furry friend may be suffering from a treatable health condition that your vet can diagnose and treat before it gets worse.

Of course finding time to visit a vet isn't always easy. ManyPets insurance customers get unlimited, 24/7 online vet advice as part of their policy. Great for getting a fast, expert opinion and deciding on next steps.

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Common causes of bad breath in cats

There are a number of oral health conditions that can lead to kitty halitosis, and some of them may require immediate treatment. Here are a few of the most common causes:

Dental disease

Dental disease is the most common cause of bad breath in cats. (Humans, too!) When plaque and tartar accumulate around your cat’s teeth, gum disease and tooth decay are often right around the kitty corner.

If you want to get technical here’s what happens. The bacterial buildup around your cat’s teeth and gums will start to work its way up to the tissue that holds the tooth within the skull bone, called the periodontium. When this connection is disrupted, teeth can become loose, painful, infected, or even necrotic.

Inflammatory gum conditions

Conditions like gingivitis and stomatitis can cause inflammation and irritation in the mouth, leading to bad breath. Your vet can address these issues during a dental cleaning. More advanced treatment may be necessary if the problems are severe.

Abscesses from diseased teeth

Infections in the root of a tooth can create pus-filled pockets called abscesses, that emit a distinct, unpleasant odour. Again, this is an issue that your vet may be able to attend to during a cleaning. "Typically, abscessed tooth roots will require surgical removal of the affected tooth,” explains vet Dr. Kirsten Ronngren, DVM, MRCVS. “And don't fear — pets are much more comfortable without these diseased teeth.”

Foreign objects lodged in the teeth

Aside from naturally-arising oral hygiene issues, cats can court halitosis by chewing on food items that aren’t meant for them or on other foreign objects like bones.

Such items can get stuck in your furry friend’s teeth and begin to rot. This can even lead to infections, abscesses, or broken teeth, any of which can lead to a malodorous feline mouth.

Other health conditions that may lead to smelly breath

Oral issues aren’t the only health conditions that can cause bad breath in cats. Halitosis can reflect your cat’s overall health or even a specific health condition. So again, it's essential to seek vet advice if you notice any concerning changes in your furry friend’s breath.

Here are some conditions that might be contributing to your cat’s halitosis:

Oral tumours

Heaven forbid this is the cause, but unexplained foul breath can result from oral cancer. You should also look out for common accompanying symptoms like drooling or difficulty eating.

A prompt vet examination and possible biopsy will be necessary for a definitive diagnosis. Your vet may even be able to initiate an effective round of cancer treatments for your cat. The prognosis will vary based on the tumour type and your individual pet.

Chronic kidney disease (CKD)

Chronic kidney disease is especially prevalent in older cats, and it can cause a very distinct form of halitosis: your cat’s breath may smell like ammonia. If that’s what you’re smelling, be sure to relay that information to your vet.

CKD occurs when your cat’s kidneys lose their ability to function properly, leading to the buildup of toxins in their bloodstream. Regular vet check-ups, blood tests, and early detection are vital to managing CKD and maintaining your cat's quality of life.


If your cat's breath has a fruity or sweet smell, that may be a sign of feline diabetes, aka “diabetes mellitus.” Like humans, cats get diabetes when their bodies start struggling to regulate blood sugar levels. That sweet-smelling breath is the result of their body’s breakdown of fats for energy.

Diabetes requires close monitoring, insulin therapy, and dietary adjustments. Prompt vet intervention is crucial to managing the condition as effectively as possible.

Gastrointestinal issues and liver disease

Digestive issues or liver disease can also lead to foul-smelling breath in cats. An intestinal obstruction may lead to changes in your cat’s breath.

Liver disease may also cause a buildup of toxins in the body, which can also manifest through the breath.

Timely diagnosis and appropriate treatment are essential for addressing these underlying conditions. Bad breath may well be the least of your concerns, but it can be a helpful indicator for you as a pet parent that there's a problem that must be investigated.

Methods to prevent bad breath in cats

The good news is that there’s a lot you can do to prevent your cat from developing gum disease in the first place. It all starts with at-home dental care. Yes, you can help keep your cat’s mouth and teeth healthy at home.

Don't skip routine vet visits

Routine vet visits are fundamentally important for your cat's well-being.

Regular check-ups allow your vet to identify health issues — and just as importantly, potential health issues — early on. Whether your cat has dental problems, an internal disease, or is at risk for a future condition, routine check-ups can help your vet diagnose these issues early. Perhaps before they’ve even become symptomatic.

Brush your cat's teeth

Granted, some cats may resist their loving parent’s attempt to force a foreign object into their mouth, but just do your best. If your cat scratches or bites you or merely meows forcefully, slower desensitisation training may be needed to adjust them to the toothbrush.

“In some cases, your safety and your cat’s stress will be limiting factors when it comes to tooth brushing, meaning you may need to resort to other methods of preventative dental health,” says Dr. Ronngren.

Use vet-approved cat dental products and treats

Certain cat foods, treats, and pet dental products are also specifically designed to bolster your cat’s oral health and improve their bad breath. These products often contain abrasive textures that help slow tartar buildup.

Just be sure to consult a vet to make sure that any new treats or food are suitable for your cat’s teeth and diet. The Veterinary Oral Health Council has a great list of approved dental health products for pets, with recommendations from board-certified veterinary dentists.

Provide your cat with a balanced diet

A well balanced diet can be helpful for your cat's breath and is crucial for their overall health. Your vet can offer tailored dietary recommendations to support your cat's individual health requirements.

How to treat bad breath in cats

Again, if something seems wrong — whether that’s smelly breath or any other symptoms of illness  — you should visit the vet right away instead of waiting for your next appointment.

Once tartar and plaque have built up on your cat’s teeth, the only way to deal with the problem is with a professional dental cleaning in a vet’s office. Realistically, your cat may need some dental cleanings over the course of their life, even if you’re a dedicated tooth-brusher.

In addition to plaque and tartar buildup, such cleanings might address issues like broken teeth and dental abscesses, which can also lead to bad breath.

A full cleaning is performed under anaesthesia and is the safest and most effective way for your vet to fully evaluate your pet's mouth and treat any issues found. Vets typically use the same high-quality equipment that human dentists use, such as electric scalers and polishers or digital dental x-rays.

How ManyPets may help

Having the right insurance in place can reduce the worry of costly vet visits.

Our Complete pet insurance policy covers dental accidents and illness, as long as your pet’s had a dental check-up within the last twelve months, and you’ve followed any dental treatment recommended by a vet within six months. All our other policies cover dental accidents. 

Learn more about our cat insurance and how we can help you.

Add the MoneyBack optional extra for 20% back at the end of the policy year if you don’t need to claim.