What's Wrong With Your Dog. Coughing in dogs may be a symptom of heart disease in humans. Dog breath is n’t precisely known for smelling minty fresh—but if your pooch is suffering from systematically bad breath, then it could mean that something more serious is at.

Older dogs will naturally begin to have less energy, but if your dog is normally active, fatigue could be a sign of something wrong. Here is a more thorough overview of what a lethargic dog may exhibit. The signs of a lethargic dog can vary from increased sleepiness to appetite changes to lack of stamina.