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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.
  • Book an appointment with 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

Make an appointment with 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.

Find out whether you are eligible for free or low cost PDSA veterinary treatment by using our eligibility checker.

Published: February 2020

PetWise Pet Health Hub – brought to you thanks to support from players of People’s Postcode Lottery 

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

Illustrations by Samantha Elmhurst