The dog undergoes reverse sneezing to expel an irritating agent. Normally, a regular sneeze helps by expelling the irritating agent in the nasal cavity. Coughing will make the irritating agent move further down in the trachea. Reverse sneezing is a way of the dog's body to expel an irritating agent slightly further down at the nasopharynx or the area near the soft palate. Some examples of possible causes of irritation that result in reverse sneezing include: allergies, nasal mites, exercise intolerance and elongated soft palate. An elongated soft palate mostly occurs in dogs of brachycephalic breeds.
