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Halitosis in Cats

PlaqueHalitosis is an offensive odor coming from the oral cavity. 

What causes halitosis in cats?

Halitosis is caused by:

  • bacteria associated with plaque,
  • calculus or tartar,
  • decomposing food particles retained within periodontal pockets,
  • persistent bleeding due to coagulation abnormalities, and
  • tissue necrosis. 

Contrary to common belief, neither normal lung air nor stomach aroma contribute to halitosis.

Support loss caused by advanced periodontal diseaseThe most common cause of halitosis in the cat is periodontal disease from plaque (biofilim).  Bacteria are attracted to the acellular biofilm on tooth surfaces which are formed from the precipitation of salivary glycoproteins (the pellicle). Biofilm forms over a freshly cleaned and polished tooth as soon as the patient starts to salivate; the bacteria attach to the pellicle within 6-8 hours. Within days, the plaque becomes mineralized, producing rough tartar or calculus which accumulates more plaque and causes inflammation of the marginal gingivia. As plaque ages and gingivitis progresses into periodontitis (tooth support loss), the bacterial flora changes from “good” bacteria to destructive bacteria.

While this is occuring, the periodental ligament becomes infected causing destruction of tooth support. The primary cause of  bad breath in dogs is the bad bacteria causing putrefaction that generates smelly sulfur compounds.

Volatile sulfur compounds may also play a role in periodontal disease affecting the integrity of the tissue barrier, allowing endotoxins to produce periodontal destruction, endotoxemia, and bacteremia.

3 How is halitosis treated?

 Treatment of halitosis in the cat involves eliminating the cause(s). First, the teeth need to be thoroughly cleaned and polished under general anesthesia. Cleaning removes plaque and calculus above and below the gum line (with the help of hand instruments and scaler tips designed to be used under the gum line).

After teeth cleaning, a tooth-by-tooth examination for periodontal support loss is conducted. Intraoral dental x-rays are inspected to complete the oral assessment. Often, those teeth affected by advanced periodontal disease need to be extracted. 

In cats where periodontal pockets are consistent with stage 2 and 3 periodontal disease, and/or when bleeding is found on probing, local anti-microbial administration may help to reduce halitosis by decreasing bleeding and diminishing pocket depths.

How can halitosis be prevented?

After the causes of halitosis have been identified and elimnated, daily plaque control is an essential part of controlling and preventing halitosis from recurring.

Tooth brushing at least three times a week is highly recommended. Using products approved by the Veterinary Oral Health Council (VOHC.org) have also been shown to slow the accumulation of plaque and/or tartar and are endorsed by the American Veterinary Dental College.

© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Last updated on Feb 10, 2016.