Bad Breath and Drooling in Cats

Causes, Treatment, and Prevention

Veterinarian examining the mouth of a cat
Oral examinations should be part of every physcial examination in a cat. numbeos / Getty Images

It's normal for cats to have occasional bad breath and drooling, but it can sometimes signify a severe underlying condition. Cats with symptoms like nausea, face swelling, and balance issues, in conjunction bad breath and drooling are likely experiencing more significant health issues. Serious causes of bad breath and drooling in cats include kidney diseaseoral tumors, and intestinal blockage. Your vet will examine your cat for underlying health issues and treat the bad breath and drooling based on its cause. The prognosis is good for cats with minor conditions. It's essential to maintain a good oral hygiene routine to prevent health issues in your cat's mouth. 

What Is Bad Breath and Drooling?

Bad breath (halitosis) and drooling is usually caused by an underlying condition. Some bad breath is to be expected from a cat eating pungent cat food, but when the odor is abnormally strong, it could indicate a more serious cause. Similarly, some drooling is normal in a happy, relaxed cat, but an excess or sudden onset is cause for concern.

Symptoms of Bad Breath and Drooling in Cats

The symptoms of bad breath and drooling in cats are usually related to underlying causes. If you notice any concerning symptoms in conjunction with bad breath or drooling, visit your vet right away.


  • Foul odor
  • Bleeding gums
  • Pain
  • Face swelling
  • Vomiting
  • Inability to eat or drink
  • Balance issues
  • Unable to close mouth
  • Difficulty breathing
  • Mouth sores
  • Pawing at face
  • Discolored eyes

Bad breath and drooling in cats have symptoms related to various conditions. Many symptoms are associated with the mouth and face, such as the inability to use the mouth, oral sores, and bleeding gums. Other symptoms may not seem to be associated with the mouth at first glance but can indicate a severe condition causing the bad breath and drooling. For example, if your cat is drooling and can't balance itself, it may have a neurological issue. Or, if your cat has bad breath and bloody gums, it may have stomatitis.

Causes of Bad Breath and Drooling

There are many causes of bad breath and drooling in cats, and while most of them involve disease within the mouth, there are other explanations as well.

  • Oral tumors: Growths or tumors inside a cat's mouth can grow, become infected, and emit a foul odor. This causes bad breath in your cat and drooling if the tumor is large enough to cause trouble swallowing. Tumors inside the oral cavity are sometimes challenging to detect, as they can grow in the back of the mouth or under the tongue. Typically, it tumors aren't noticed until they begin to cause issues.
  • Periodontal disease: Your cat's teeth can harbor bacteria and food debris if not regularly brushed. These materials can accumulate and cause infection, resulting in periodontal disease. Periodontal disease may also include abscesses under the gums and bad breath and drooling. If not addressed, your cat's teeth may fall out or need to be extracted.
  • Kidney disease: Kidney disease or failure can sometimes cause bad breath in cats. Kidneys filter toxins from the blood, and if they are not operating correctly, a toxin build-up can result in halitosis.
  • Liver disease: If your cat's breath smells like bile or vomit, liver disease could be to blame. The liver helps detoxify the body and produces bile, which aids in the digestion of fats. But if the liver is not working correctly, you may smell a foul odor coming from your cat's mouth. Vomiting is also often seen in cats with liver disease, which can also cause bad breath.
  • Diabetes: Bad breath as a result of uncontrolled diabetes has a distinct fruity or sweet smell.Since a cat with diabetes cannot convert fatty acids from fat tissue to triglycerides for energy, the fatty acids are converted to unusable ketones instead. These ketones cause the sweet-smelling breath often noticed in cats in diabetic ketoacidosis.
  • Intestinal blockage: Cats are known to eat things they shouldn't, and sometimes these items cause a blockage in the intestinal tract. Circulation may become cut off, leading to organ failure. The necrosis and vomiting in a cat with an intestinal blockage can lead to bad breath.
  • Oral trauma: Trauma to the mouth can result in bad breath and drooling. Infections or bleeding from the wound cause discomfort, a foul odor, and drooling that often contains blood. This type of trauma may occur after a cat bites an electrical cord or has a piece of string cutting off the circulation on its tongue.
  • Respiratory disease: Some cats have respiratory issues that affect their sinuses and nasal passages. These issues usually involve inflammation and are referred to as rhinitis and sinusitis. The inflammation may also lead to infection and bad breath, and drooling.

Diagnosing Bad Breath and Drooling in Cats

You will likely be able to make an at-home diagnosis of your cat's bad breath or drooling, after which you will need to visit your vet to determine the underlying cause. Your vet will perform a thorough physical examination of your cat's mouth and run blood analysis and urinalysis tests. If your vet suspects that your cat has a gastric disease, they may perform an abdominal ultrasound, endoscopy, or tissue biopsy. Sometimes, sedation or total anesthesia is necessary to examine the mouth.

Treatment & Prevention

Treatment of bad breath and drooling in cats depends heavily on its underlying causes. If the underlying cause is minor, such as gingivitis, your vet may prescribe a daily tooth-brushing routine. If the cause of your cat's bad breath or drooling is due to food lodged in its teeth, your vet will remove the food. Sometimes, a vet will recommend tooth extractions and prescription medications. Your vet will determine the treatment plan accordingly for more serious underlying causes, such as liver disease or cancer.

The best way to prevent bad breath and drooling in cats is to brush your cat's teeth daily. Not all bad breath and drooling indicate an underlying disease, but continuously monitor your cat's oral health for anything out of the ordinary. Make sure it gets a mouth examination and cleaning at each vet visit.

Prognosis for Cats With Bad Breath and Drooling

The prognosis for cats with bad breath and drooling depends on its underlying cause. Bad breath or drooling resulting from poor oral hygiene or diet can usually be resolved by changing the brushing routine or choosing a less pungent-smelling food. Minor health issues and infections are generally responsive to antibiotics. The prognosis for bad breath and drooling caused by serious disease varies.

  • How do I know if my cat's bad breath is a problem?

    It's normal for cats to have bad breath due to pungent cat food, but if the odor is extreme and unusual, visit your vet.

  • Is some drooling normal in a cat?

    It's normal for cats to drool when they're feeling relaxed. If your cat is drooling excessively throughout the day, or if it's a new development in its behavior, something may be wrong.

  • Can I treat my cat's bad breath at home?

    If there isn't a serious underlying cause for your cat's bad breath, you can usually resolve it with daily tooth-brushing.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.
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  4. Does Your Cat Have Bad Breath?. Cummings School of Veterinary Medicine at Tufts University.