A Guide to Dog Respiratory System Illnesses

In the dog, respiratory disorders are usually caused by infection, immune-mediated reactions or inhalation of an irritant or toxin.

The function of your dog's respiratory system is to deliver oxygen to the blood and distribute it throughout the body. Carbon dioxide is removed from the blood. This exchange occurs in the lungs. When this exchange is compromised, illness results.

Respiratory illnesses are common and the most noticeable symptom is a dog breathing problem: coughing, wheezing and labored breathing. All dogs are at risk of respiratory ailments regardless of age or overall health.


Bronchitis or tracheobronchitis is an acute or chronic inflammation in the dog lung, trachea or bronchial tubes. It often occurs as a result of another respiratory disorder such as kennel cough. It can also be caused by parasites, smoke inhalation and exposure to chemical fumes.


Tumors and cancers can affect your dog's respiratory system. The sinus, larynx, trachea and lungs are all susceptible to canine cancers. Fortunately, airway cancers are rare in dogs.

Nasal cancers occur most often in older, male dogs and the symptoms include nasal discharge and nose bleeds. Larynx and tracheal tumors are rare in dogs, but symptoms include high-pitched wheezing after exercise and voice changes. Cancer that originates in the lungs accounts for only 1 percent of canine cancers, but the numbers are increasing. Signs vary, but may include cough, poor appetite, lethargy, regurgitating and fever.

Kennel Cough

Kennel cough is a contagious viral or bacterial infection that causes acute inflammation of the upper airways. It spreads rapidly and may resolve on its own but it can develop into bronchopneumonia in puppies or dogs with a weakened immune system.


Laryngitis is an inflammation of the larynx caused usually by an upper respiratory infection or direct inhalation of dust, smoke or irritant. Fluid builds up in the airway and mucous membranes may swell, putting the dog at risk for a breathing obstruction. Flat-faced dogs like Pugs are most susceptible.


The most common cause of pneumonia is a viral infection in the lower respiratory tract. The lungs and airways become inflamed, causing breathing difficulties and poor oxygen exchange. Signs of pneumonia include lethargy, labored breathing and a deep cough. There may be fever.


An upper respiratory malfunction, rhinitis is an inflammation of the mucous membranes of the nose. It is usually a result of a sinus infection. It can develop into a more serious condition, putting the lungs are risk for infection. It is usually viral in origin. Signs include nasal discharge, snoring, open-mouthed breathing and pawing at the face. Tear production may be increased. Dogs may "reverse sneeze," taking in short rapid breaths to clear the nose.

Tracheal Collapse

Tracheal collapse is most common small and toy dogs. Its cause is unknown, but symptoms include a dry, chronic cough. Overweight dogs are more at risk.

Stress, sudden diet changes, poor ventilation and dusty environments can contribute to and exacerbate respiratory conditions. Vaccines are available for some disorders, but a sanitary environment is always the best option for the health of your dogs.