The main airway to the lungs known as the windpipe or trachea branches into smaller airways called bronchi which branch several more times as they travel to the deeper parts of the lung. (Anatomy of the lungs and airways: dog/cat)
There are many causes of cough. A thorough history and physical examination help the veterinarian decide which causes of cough are most likely in your pet and helps him or her decide which diagnostic tests to recommend and which therapies are most likely to be effective. Cough originating from the trachea may be stimulated by lightly squeezing the trachea. Cough due to heart disease may be accompanied by a murmur or abnormal heart rate or rhythm.
NB-As this detailed article explains, pets cough for many reasons. Cough suppressants, antibiotics and anti inflammatories (usually steroids) are the most common treatments. I can't think of any of my previously coughing patients who have needed any of these as we work through the symptoms with the body.--Dr. Jeff
Please note: The information provided here is intended to supplement the recommendations of your veterinarian. Do not disregard veterinary advice or delay treatment based on information on this site. Nothing can replace a complete history and physical examination performed by your veterinarian. -Dr. Jeff