Bad breath in dogs

photo of dog on white background


  • Does your dog have smelly breath? Has it been going on for a while?
  • Bad breath is often due to dental disease, but can also be cause by other, more serious conditions.
  • Bad breath isn't normal and should always be checked by your vet.
  • Contact your vet if your dog has bad breath. Make a same-day appointment if their symptoms have come on suddenly, they are in pain or seem unwell.

Causes of bad breath

Bad breath in dogs can be caused by:

  • Dental disease such as tartar build up, gum infections, and tooth root abscesses
  • Airway infections in the lungs, sinuses or windpipe.
  • Stomatitis (inflammation inside the mouth) which can be caused by infections, allergies or eating something that irritates the mouth.
  • Something stuck in the mouth such as a piece of bone or stick.
  • Gut problems such as infections, vomiting bugs or blockages.
  • Diet for example fish based diets.
  • Kidney disease can cause the breath to smell like ammonia (similar to bleach).
  • Liver disease can cause foul, sweet, musty breath.
  • Diabetes can cause the breath to smell sweet (similar to pear drops or nail polish remover).
  • Lumps/masses in the mouth often become infected and smell.

When to contact your vet

Contact your vet if you notice a change in your dog’s breath. They will investigate and treat the cause. Make a same day appointment if your dog’s breath has changed suddenly, they are painful, or seem unwell.

Consider insuring your dog to help with healthcare costs in the future.

Published: February 2020

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Written by vets and vet nurses. This advice is for UK pets only.

Illustrations by Samantha Elmhurst