A dog’s abiltiy to smell is affected by poor dental care. Your dog’s teeth need daily cleaning and hygiene just like we do. Dogs really don’t like you messing with their teeth unless you start to do this at a young age. When the puppy is as young as eight weeks, put your fingers in its mouth everyday and rub and feel it’s teeth. It isn’t recommended to begin brushing at this early age, but I would suggest putting a pet toothbrush in their mouth very gently around the teeth to get them used to it. There are gels available from pet stores that aid in keeping the teeth clean. When the dog gets older, I would recommend using these gels daily and also a light brushing. Even if your dog is not a working dog, such as an air scenter or trailer, they still rely heavily on their sense of smell.