Bad dog breath is caused by the accumulation of bacteria in your dog’s system. The locations of this bacterial build-up can range from the mouth to the lungs to parts of the digestive system. For the most part bad breath in dogs can be attributed to gun disease which is caused by a build-up of tartar and plaque around the dog’s teeth and gum line. Chronic bad breath in dogs can indicate a more serious dental or internal problem and should be checked out as soon as possible. It can also be an indication of larger medical problems in the respiratory and digestive system if it continues despite better dental care. Long story short, BRUSH YOUR DOG’S TEETH EVERY DAY!