A normal healthy dog has nice breath and no real odor to the ears or face. If your dog seems to have halitosis, or there is a persistent bad odor to its face, an investigation is in order. Halitosis, or bad breath, happens for many reasons, but the most common causes are from dental disease or an upset stomach. In the case of dental disease, tartar accumulation on the teeth allows increased bacterial growth in the mouth. The bacteria not only make things smell bad, they may also cause gum disease that can progress to tooth loss. This can happen even with the small amount of tartar that accumulates in a week’s time without proper oral hygiene (tooth brushing). A “sour” stomach can also cause bad breath, probably for the same reason. The stomach is usually sterile due to the high acid content associated with normal digestion. If digestion is upset for some reason, bacterial counts increase and bad breath can occur.

If your dog has persistent halitosis, you should consult with your veterinarian to find the cause.

Normal canine ears have a pleasant “doggy” smell. Ears that are infected with malassezia (yeast) overgrowth have a sickening sweet odor like bad tennis shoes. Ears with a bacterial infection can smell as bad as sewage! Even a wax buildup in a dog’s ears can be detected as a change in odor to people with sensitive noses. If a malodorous ear does not become pleasant smelling after routine ear cleaning, an evaluation with an otoscope should be performed by a veterinarian or veterinary technician to check the deep ear canal for problems.

Occasionally, a bad odor on the face of a dog can be localized to the lower lip folds. An increase in bacteria or yeast can occur due to the moisture there, and can lead to infection or dermatitis. This is called “lip fold pyoderma,” and is readily treated with topical cleansing (a mild ear cleaning solution works well) and sometimes systemic (oral) antibiotics. This type of odor can be evaluated by passing a cotton tipped applicator over the area and checking the smell.