If your dog has a bad case of halitosis, it’s time to take action.  That means getting him checked out by a veterinarian. Often the cause is periodontal disease or gingivitis.  Consider if your dog has any other symptoms such as inflamed gums, pain or excessive drooling. Periodontal disease is quite common in dogs.  If your vet finds no underlying cause for the stinky breath, try improving your dog’s oral hygiene. Brush his teeth regularly and feed him special dog treats that are designed to improve bad breath. In general, chewing helps to promote good oral hygiene because it scrapes the teeth clean. Some small dogs may also require regular tooth cleanings.