Brachycephalic Syndrome in Boston Terriers


Brachycephalic Syndrome is also known clinically as Brachycephalic Airway Obstruction Syndrome (BAOS).  It is predominantly manifested in brachycephalics or those breeds of dogs which have short noses brought about by the a unique anatomical combination of an elongated soft palate, everted laryngeal saccules, and stenotic nares.

An elongated soft palate is a condition where its tip extends beyond into the respiratory airways and obstructs the intake of air into the lungs. Everted Laryngeal Saccules occur when the soft tissues near the vocal cords are pulled into the windpipe (trachea) and hamper the entrance and exit of air. Stenotic nares, on the other hand, is the malformation of the nostrils making them narrow and collapse inward when the dog takes in air during inhalation. Dogs with stenotic nares often experience difficulty in breathing through its nose. There are also cases of Brachycephalic Syndrome when the dogs have a collapsed larynx, a narrow windpipe, or paralysis involving the cartilages of the larynx.

Aside from the Boston Terrier, other common brachycephalic dogs are the Pug, English Bulldog, Pekingese, and Shitzu.   Because of their unique anatomy, these brachycephalic breeds face breathing difficulties from the time they were born.  There may be varying degree of barriers in their respiratory airways and signs may vary. The mildest cases will oftentimes be manifested only by noisy breathing while the most serious ones often result in collapse when undergoing strenuous activity.

If left unattended, a brachycephalic dog may develop grave respiratory issues that may interfere in their capacity to enjoy life to the fullest.


Most brachycephalic dogs are observed to be snuffling and snorting. In most cases, these are relatively mild symptoms of Brachycephalic Airway Obstruction Syndrome (BAOS). However, there are brachycephalic dogs that will develop more serious signs such as coughing, noisy breathing, gagging, fainting episodes, and tiring very easily when exercising or just playing around. If left unattended, these episodes can subject the heart to increased strain that can lead to more grim prognosis.

If brachycephalic dogs are made to exercise especially in warm weather, their body temperatures can quickly increase several degrees higher and can lead to hyperthermia.  In an effort to quickly bring down their body temperatures to the normal level, dogs compensate with increased panting which can result in further constriction of the airways. Some dogs may also suffer from gastrointestinal problems because of a decrease in coordination between swallowing and breathing.  Thus, you can observe dogs gagging or vomiting which can lead to more serious complications such as aspiration pneumonia when they breath in food particles and even their own saliva.


Diagnosis of BAOS is often reached when made based on your dog’s breed and the clinical manifestations. Your Veterinarian will perform more tests to confirm the initial diagnosis. These tests will include a physical exam, using the stethoscope to listen to the chest sounds and x-rays to check for the presence of heart or lung disease. The nostrils are also examined closely to determine if the dog possesses stenotic nares.  Your dog will also be put under sedation so that the mouth and larynx can be examine to determine whether the soft palate is elongated and whether or not the laryngeal saccule is everted.


Mild cases of BAOS can be treated with tranquilizers and the administration of oxygen and anti-inflammatory steroids. However, more severe cases need to undergo surgery to correct the anatomical abnormalities causing the condition.

Certain preventive measures can also be undertaken by the owner in order to help manage BAOS:

  1. Obesity may cause breathing difficulties thus it is doubly important to watch your dog’s weight.
  2. Avoid exercise and other stressful situations during hot or humid weather.
  3. Get rid of the neck collar. Instead, use a dog harness.
  4. Bring your dog to your Veterinarian once you see signs of breathing difficulties, cyanosis, or your dog collapses.