Typical symptoms may include a long cough, breathing difficulties and gagging. You can know whether your dog is suffering from respiratory problems if you pay close attention to the symptoms. Some common signs that indicate a respiratory issue are a lasting cough, persistent dry cough, rapid breathing, difficulty breathing, gagging while trying to live, and other symptoms.  The majority of these respiratory problems can be cured easily if you can detect them early. Sometimes people tend to ignore symptoms like a clicking noise coming from the mouth of the dog.