Bad Breath Be Gone!
November 18, 2025
Nancy Kerr
If you’re noticing a funky smell coming from your kitty’s mouth, you’re probably wondering: why does my cat have bad breath? Also known as halitosis, bad breath can be caused by many different things. How can you determine if this is from something your kitty ate or if it’s a more serious health issue? Let’s start with a baseline: What should a cat’s breath normally smell like? There are varying opinions on this subject, one being:
“Ideally, a cat’s breath should not have a strong odor. It may have a slight, almost sweet smell, similar to the scent of a newborn baby’s breath. If your cat’s breath smells foul or unusually strong, it could be a sign of dental issues, gastrointestinal problems, or other health issues that need to be addressed by a veterinarian.”1
For those of us not experienced with newborns, a cat’s breath should really not have an odor at all.
Another opinion is that (unlike dogs) cats do have “cat breath,” a mild odor present even in a cat with a healthy mouth. It is a stronger than normal breath odor referred to as halitosis, and associated with a variety of diseases. So, really smelly cat breath could signal an issue.
Was It Something I Ate?
Did you recently feed your cat strong smelling food like tuna or sardines? Some brands and/or flavors of commercial cat food may also cause your cat to have bad breath. Sudden dietary changes can upset your cat’s gastrointestinal tract and lead to bad breath. Any new food should be introduced gradually.
Show Me the Teeth
If you have ruled out your cat’s diet, the next step is to do a basic oral exam. If you cat is amenable to having its mouth handled, try examining the cat’s teeth and gums for any signs of redness, swelling, bleeding, or tartar – especially on the rear molars. Bleeding gums can indicate “advanced gum disease (gingivitis). It is also often a symptom of periodontitis, which can lead to serious health problems if left untreated.”2 If your cat does not want to have its mouth checked, make an appointment with a veterinarian as soon as possible.
When It Could Be More
Sometimes bad breath can be a sign of other health issues. In addition to the signs of redness, swelling, bleeding, or tartar, there are other symptoms to watch for if your cat’s unpleasant breath odor persists or is accompanied by additional symptoms such as:
If you note “loss of appetite or lethargy (tiredness, lack of energy), you should have your cat examined by a veterinarian immediately. Early diagnosis and treatment are important to prevent serious health problems. Also watch for weight loss, increased drinking and urination (polydipsia/polyuria). If these symptoms persist for more than a few days or worsen, they may indicate diseases such as diabetes mellitus, kidney disease, liver disease, or tumors. The duration of symptoms varies depending on the cause.”2
Bad breath can also be caused by tumors in the mouth or gastrointestinal tract. Items such as food debris or toy parts can become lodged in the mouth and cause bad breath. Halitosis is associated with uremia – a buildup of toxins in the blood caused by kidney failure. Cats in uremic crisis will have significant halitosis.
Other things that may lead to bad breath include disorders of the digestive system – especially those that result in frequent vomiting. “Diseases that cause ulcers in the mouth, such as infection from the feline calicivirus, are associated with halitosis. Conditions not specific to the mouth will almost always have additional symptoms that accompany these disorders, including vomiting, diarrhea, low energy, excessive thirst, excessive urination, and a poor appetite.”3
Home Dental Remedies
If your cat is only experiencing redness, swelling, bleeding, or tartar, you can try some home remedies to help alleviate the bad breath before seeing the veterinarian, who will generally recommend brushing your cat’s teeth at least a couple of times a week. The following is a video for how to do this: https://youtu.be/3dBySVcgIYI.4 Of course, some cats will not tolerate having their teeth brushed.
If this is the case with your cat, there are products available that should decrease the accumulation of plaque once the teeth have been professionally cleaned. This includes using dental wipes twice a week to clean the teeth, and feeding dental treats every day. “Oral care products containing zinc can inhibit the formation of odor through their natural attraction to sulfur; zinc and hydrogen sulfide combine to form the insoluble compound zinc sulfide. Zinc also interferes with microbial growth and calcification of microbial deposits that can cause halitosis.”5
The Veterinary Oral Health Council only accepts safe dental products that have been proven to reduce the accumulation of plaque and tartar based on scientific studies. These products include dental diets, treats, water additives, and topical applications. Check out VOHC.org-approved products for cats or ask your veterinarian for recommendations. Note: Dental diets can be high in calories, so care should be taken not to over feed.
Gum Disease
“By far the most common cause of bad breath in cats is periodontal (gum) disease. By only two years of age, 70% of cats will have some form of periodontal disease.”3 However, some kittens and young cats can get what is referred to as juvenile gingivitis.
“Why does gum disease cause bad breath in cats? As soon as a cat eats a meal, plaque (a sticky substance containing food particles, saliva, and bacteria) starts to accumulate on the surface of their teeth. If this plaque is not removed by brushing or other methods, it will harden and turn into tartar within a few days. Tartar, which has a yellow-to-brown color, is rough and will then attract more plaque, which leads to more tartar – it’s a vicious cycle. Plaque and tartar accumulation first causes gingivitis, or inflammation of the gums. If this isn’t treated in time, it will eventually lead to inflammation of the deeper tissues supporting the teeth, which then causes infections below the gums and eventually tooth loss. All of this infection, inflammation, and tooth decay creates very bad cat breath.”3
Dental Cleaning
If the at-home remedies do not make any difference in your cat’s breath, you will need to make an appointment with your veterinarian for a dental cleaning. A physical exam will be done before the procedure takes place:
“First, a thorough examination of the entire oral cavity is necessary. Then the teeth must be thoroughly cleaned and polished under general anesthesia. Cleaning removes plaque and tartar (calculus) above and below the gumline (with the help of hand instruments and scaler tips designed to be used under the gumline). After teeth cleaning, a tooth-by-tooth examination is conducted. Intraoral dental X-rays are inspected to assess structures beneath the gumline. Often, those teeth affected by advanced periodontal disease or tooth resorption need to be extracted.”5
The veterinarian may prescribe medications to help with the dental issues causing the bad breath. “Chlorhexidine is an antiseptic effective against pathogens that reduces bacteria in the mouth, thereby combating bad breath. Metronidazole is an antibiotic for bacterial infections in the mouth. It reduces inflammation and bad breath.”2 Probiotics (which work to stabilize gut flora) can indirectly improve bad breath.
If the cause of bad breath is determined to be unrelated to the teeth and gums, such as untreated diabetes, your cat’s breath should improve once the disease has been properly treated. If your cat has health insurance, check to see how much dental coverage is included. The cost of dental work increases depending on how much work needs to be done.
Going Forward
Keeping your cat’s teeth and gums clean and free of bad odors will help to prevent your cat from developing painful, diseased gums and teeth later in life. It can also help to promote better heart, lung, kidney, and liver function, and increase your cat’s longevity. Regular dental examinations are recommended by veterinarians to help treat and prevent halitosis from reoccurring.
“Some cats are more prone to dental issues and bad breath due to genetics. Breeds such as Persians and Siamese are known to have dental problems, so extra care should be taken to keep their teeth clean. Older cats are more likely to develop dental issues and bad breath as they age. It is important to monitor your senior cat’s oral health and make adjustments to their diet and dental care routine as needed.”6
Unpleasant breath odor in cats should be taken seriously, as it can be a sign of various health issues especially if the bad breath persists despite proper dental care and diet. Respiratory infections, kidney disease and diabetes are just a few of the medical conditions that can cause bad breath in cats. If you notice any other symptoms such as weight loss, lethargy, or changes in appetite, it is critical to take your cat to the veterinarian for a thorough examination.
Sources:
- What Should Cat Breath Smell Like, 2025; Accessed 09/13/2025, https://vetexplainspets.com/what-should-cat-breath-smell-like/
- Halitosis in cats: When it is a warning sign for diseases; Accessed 09/13/2025, https://vetbilim.com/en/blog/article/unpleasant-breath-odor-in-cats-causes-and-solutions/
- Liz McCalley, DVM, CCRT – Reviewed by Emily Oliver, CVT. Cat Bad Breath: Causes and Solutions, 05/30/2025; Accessed 09/13/2025, https://www.greatpetcare.com/cat-health/cat-bad-breath/
- How to Brush Your Cat’s Teeth – Veterinary Tutorial; Accessed 09/13/2025, https://youtu.be/3dBySVcgIYI
- Tammy Hunter, DVM; Jan Bellows, DVM, Dipl. AVDC, ABVP, Halitosis in Cats; Accessed 09/13/2025, https://vcahospitals.com/know-your-pet/halitosis-in-cats
- How To Treat Bad Breath In Cats; Accessed 09/13/2025, https://vetexplainspets.com/how-to-treat-bad-breath-in-cats/#