Cat's breath smell like death? It could be a sign of illness.

July 31, 2023 - 7 min read

The information in this article has been reviewed by Kirsten Ronngren, DVM MRCVS on July 31, 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. And while you can’t expect it to smell like a fragrant summer meadow, a foul odor or sudden change in smell should be an immediate cause for concern.

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 bad, you should take them to the vet ASAP. Your furry friend may be suffering from a treatable health condition that your vet can diagnose and treat before it gets worse.

Read on to learn what might be causing your cat’s oral plight and how to keep their breath — not to mention their overall health — in fresh shape.

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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.

Checking Teeth Of Cat, periodontal disease

If you want to get technical (and kinda gross), 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 (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.

Vet dentist looking at red and swollen gums of a cat in a clinic

Abscesses from Dead Teeth

Infections in the root of a tooth can create pus-filled pockets (abscesses) that emit a distinct, unpleasant odor. 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 veterinarian Dr. Kirsten Ronngren, DVM, MRCVS. “And don't fear — pets are much more comfortable without these diseased teeth.”

Foreign Objects (Like Human Food) 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 (ew!). This can even lead to infections, abscesses, or broken teeth, any of which can lead to a malodorous feline mouth.

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Other health conditions that may lead to stinky 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 veterinary care 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 Tumors

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 veterinary exam 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 tumor 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.

Cat having ultrasound scan in vet office

CKD occurs when your cat’s kidneys lose their ability to function properly, leading to the buildup of toxins in their bloodstream. Regular veterinary 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 veterinary 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 (blockage) 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.

How 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.

eterinarian checking young male Maine Coons teeth health

Don't Skip Routine Vet Visits

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

Regular check-ups allow your veterinarian 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 exams can help your vet diagnose these issues early in the game — perhaps before they’ve even become symptomatic.

Fortunately, the (non-insurance) ManyPets Wellness Plan offers preventative care reimbursements like routine check-ups, professional dental cleanings, and over-the-counter dental products.

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 desensitization training may be needed to adjust them to the toothbrush.

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

“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 veterinarian 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 veterinarian 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 stinky breath or any other symptoms of illness  — you should visit the vet right away instead of waiting for your next scheduled exam.

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.

The veterinarian cleans the teeth of a cat under anesthesia in the light of a surgical lamp. The cat sleeps under anesthesia while the doctor removes tartar from her teeth.

A full cleaning is performed under anesthesia 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 can help

The good news is that, unlike with some other pet insurance companies, all ManyPets cat insurance policies may cover sick exams. Just as importantly, ManyPets may also cover dental diseases — and again, not all pet insurance companies can say the same.

ManyPets coverage is designed to keep you prepared for any unexpected health issues, so you can focus on enjoying every precious moment with your cat — in good health and good breath. Learn more about our cat insurance today and give your pet the protection they deserve.

David Teich
Lead Editor

David oversees content strategy and development at ManyPets. As Lead Editor, he focuses on delivering accurate information related to pet care and insurance. David’s editorial background spans more than a decade, including a pivotal role at Digiday, where he wrote content and managed relationships with media and tech companies. As an Associate Editor at Cynopsis Media, David wrote the Cynopsis Digital newsletter and interviewed executives and digital marketing experts in the TV industry. His background also includes film journalism. His diverse experiences in journalism and marketing underpins his role in shaping content within the pet care industry.