[header] How to diagnose canine periodontal disease [title] Smell your dog's breath. [step] Along with other symptoms, a dog who has periodontal disease may have bad breath because of the bacteria in his mouth. In some cases, bad breath may be the only noticeable symptom of periodontal disease.
[substeps] Smell your dog's breath to see if it smells foul or fresh. If your dog has noticeable bad breath, then take him to your veterinarian for an oral exam.