Why does breath smell bad?
Bacteria accumulate in dental plaque. As oral disease progresses, inflammation and infection below the gumline can produce significant odor and pain. Dental disease is common in both cats and dogs and may be advanced even when the visible tooth surface does not look dramatic.
Other possible causes
Oral masses, fractured teeth, stomatitis, foreign material, kidney disease, diabetes, and gastrointestinal disease can sometimes alter breath odor. These causes are less common than periodontal disease but are reasons persistent odor deserves an examination.
What a dental assessment may involve
A complete evaluation may include an oral exam, anesthetized periodontal probing, cleaning above and below the gumline, and dental radiographs. Home care cannot remove disease hidden beneath the gums.
Home prevention
Daily brushing with pet-safe toothpaste is one of the most effective home strategies. Veterinary-approved dental diets or products may help in selected pets. Human toothpaste should not be used.