Common Causes of Bad Breath in Cats

Estimated Reading Time 6 minutes
Common Causes of Bad Breath in Cats

A cat’s breath doesn’t necessarily smell like a bouquet of flowers, especially when fish is a staple in their diets. A piece of tuna can get stuck between their teeth, leading to an unpleasant odor. But this tends to go away once their teeth are brushed. If the foul mouth odor seems consistent and stronger than ever with time, you should have your cat checked by your veterinarian. There are several causes of bad breath in cats and most of them can be prevented and treated. Continue reading to learn more.

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What’s Causing Your Cat’s Bad Breath?

1. Periodontal (Gum) Disease

Cats benefit from having their teeth brushed regularly. Without a good home dental routine, plaque accumulates on the teeth and, over time, thickens and hardens to form tartar. Plaque and tartar buildup provide surfaces where bad bacteria can attach and multiply. As plaque and tartar continue to accumulate, it can lead to gingivitis (inflammation of the gums). Without appropriate intervention, gingivitis will eventually progress into periodontitis.

Periodontal disease is the most common cause of bad breath in cats. Early stages of periodontal disease can still be reversed with a professional dental cleaning. But without regular tooth brushing, plaque will accumulate within days.

When periodontal disease is left unchecked, the surrounding tissues of the affected tooth will be destroyed and there will be loss of bone support.

The bad bacteria that are destroying the gums and periodontal ligaments (the tissues that attach the teeth to the cat’s jawbone) are responsible for the foul odor from the volatile sulfur compounds that they generate.

Experts believe that these strong-smelling compounds may also affect the integrity of the tissue barrier, allowing endotoxins (a part of bacteria) to produce periodontal destruction, endotoxemia (endotoxins in the blood), and bacteremia (bacteria in the blood).

Periodontal disease causes severe pain, bleeding gums, and tooth loss in affected cats. The infection in the mouth can also spread to other organs when bad bacteria from the mouth enter the bloodstream.

2. Diabetes

The breath of cats with diabetes usually has a sweet, fruity odor. Affected cats may also show excessive thirst and urination and weight loss.

3. Kidney Disease

If a cat has a kidney problem, her breath may have a urine or ammonia-like odor. This is usually accompanied by other symptoms such as excessive thirst and increased frequency of urination, lethargy, appetite loss, and weight loss. Kidney disease is common in older cats (8 years and older).

If tests show that your cat has kidney disease, the treatment regimen will include dietary modification and adequate hydration. Any secondary issues that are present will also be addressed. These may include anemia, hypertension (high blood pressure), and other potential complications.

4. Stomatitis

Lymphocytic plasmacytic stomatitis is a severe inflammation of the mouth. Its occurrence is often associated with various systemic illnesses in cats such as feline immunodeficiency virus (FIV), feline leukemia virus (FeLV), and calicivirus.

Aside from putrid breath, affected cats suffer from extreme pain brought about by their swollen and bleeding gums. Even the simple act of opening their mouths causes severe pain.

Treatment may involve a professional dental cleaning, tooth extraction(s), pain management, and antibiotics.

5. Liver Disease

In addition to bad breath, cats with liver disease may also exhibit loss of appetite, a swollen abdomen, and yellow-tinged eyes and/or gums.

6. Gut Problems

Infection or blockage in any part of the gastrointestinal tract (GIT) will often make a cat’s breath smell bad. Other symptoms may also be present and are usually exhibited before any bad breath is noticed. These include stomach pain, diarrhea, and/or vomiting.

7. Mouth Cancer

A tumor in the mouth can become ulcerated and bleed. This can attract infection-causing bacteria that cause halitosis.

8. Mouth Ulcers

Mouth ulcers or cankers are often a result of poor oral hygiene. Other factors that have been found to cause ulcers in the mouth include malnutrition, acidic foods, metabolic deficiencies, viral infections, and compromised immune function.

Affected cats have areas of redness and irritation in the mouth, white or yellow-colored gums, loss of appetite, and vomiting. They may also vocalize excessively because of the pain.

9. Upper Respiratory Tract Infections

Bad breath may also be present in cats with bacterial or viral infections of the upper respiratory passages.

Treatment Option for Cats with Bad Breath

Successful treatment of bad breath in cats involves eliminating the underlying cause(s).

Professional dental cleaning will remove any buildup of plaque and tartar above and below the gum line. The procedure is done under general anesthesia so your pet will undergo certain tests before the dental cleaning to determine if she can be placed under general anesthesia without any risk of side effects.

After all the teeth are cleared of plaque and tartar, your vet will examine each tooth closely. Dental x-rays will be obtained for a more thorough oral assessment. Extraction may be indicated for teeth with advanced periodontal disease or tooth resorption.

Local antibiotic administration may be done when there is some bleeding or small periodontal pockets. This can help decrease bleeding and diminish the depths of the pockets.

If a systemic illness, like diabetes or kidney disease, is causing your pet’s bad breath, your vet will address the primary cause to eliminate her halitosis.

Can Bad Breath Be Prevented?

Regular teeth brushing at home and annual dental checks with your vet are the best ways to prevent bad breath in cats, particularly when it’s caused by periodontal disease.

Some veterinary-approved products can help decrease the accumulation of plaque and tartar. These include:

  • Dental treats
  • Dental chews
  • Dental rinses
  • Hard kibble

Tooth brushing should be introduced to your pet cat as early as possible. Make each session a positive experience for your pet by associating the brushing with your cat’s favorite treat. Start by placing a tiny amount of the toothpaste on your finger and gently rubbing it onto your pet’s teeth and gums. Toothpaste for cats is available in various flavors (such as chicken or tuna) that many cats will find hard to resist.

If your cat shows resistance, don’t press the issue. Try again the next day. Once she allows you to brush even a few of her teeth, start establishing a daily routine. Gradually go further back into your cat’s mouth without causing any stress. Avoid forcefully opening your pet’s mouth. Cats hate this. Just stretch back her lips without opening her mouth and brush the side of the teeth. If she won’t allow you to brush the insides of the teeth, don't force it. Let her coarse tongue do the work. Don’t forget to offer a favorite treat or two after each teeth brushing session.

Brushing your pet’s teeth should be done with a tooth gel or toothpaste for cats. Never use toothpaste formulated for humans because some of its components may cause digestive upset or be toxic to cats.

Your pet will also benefit from regular mouth examinations at home. Getting your pet used to the routine will take time but it will surely be worth the effort. If you notice any sign of tooth and/or gum problems, make an appointment with your vet. The sooner the problem is addressed, the better it will be for your pet’s dental and overall health and wellness.

Read more:

Dental and Oral Anatomy in Cats

Signs of Pain in Cats

3 Common Causes of Anorexia in Cats

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Published: 2/18/2022
Last updated: 2/21/2022
Dr. Sheena Haney, Veterinarian

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