Greenies are great!! My dogs absolutely looooove them!!! I brush their teeth regularly too.

If it is really bad, definitely have the vet check it out. My mother in law's pom, Casey had horrible breath for a while, and when he went in to be neutered, they checked out his teeth, and found a piece of newspaper stuck way up under one of his teeth, and that was causing the awful smell. When he was boarded, they keep newspaper in the kennel, and they think that's what it was from.