November 12, 2023

Brachycephalic Obstructive Airway Syndrome (BOAS)

November 12, 2023

Brachycephalic Obstructive Airway Syndrome (BOAS)

Commonly affected breeds:
Pug / French Bull Dog/ English Bull dog/ Boxers/ Pekingese/ Boston terrier

Symptoms: increased huffing and puffing (noisy breathing), some dogs will retch and gags – these symptoms get worse with exercise and hot weather. Exercise intolerance, cyanosis (blue gums due to lack of oxygen) and occasional collapse.


  1. Stenotic nares - where the nostrils are too small to allow adequate passage of air making breathing through the nose difficult.
  2. Elongated soft palate - where the soft palate is too long. In these cases, the soft palate is excessively long allowing it to sit within the opening of the trachea (windpipe) and thus obstructs normal airflow. The elongated soft palate creates turbulent airflow resulting in the increased respiratory noise we hear in brachycephalic dogs, including snoring.
  3. Tracheal hypoplasia - where the trachea (windpipe) is too small. This condition cannot be treated however addressing the other airway issues may be of benefit.
  4. Tonsillar hyperplasia or enlarged tonsils. This is common in brachycephalic breeds due to chronic inflammation. Some surgeons advise tonsillectomy at the time of airway surgery. This is typically assessed with each individual.
  5. Everted or swollen laryngeal saccules - These saccules normally sit either side of the floor of the larynx just in front of the vocal folds / cords. In brachycephalic dogs the increased effort of breathing may result in the saccules becoming swollen resulting in obstruction of airflow. Swollen laryngeal saccules is the first stage of collapse of the larynx - a very serious condition.
  6. Overgrowth of the nasal turbinate bones - this occurs in some cases and may require additional surgery if breathing is not improved by correction of the above problems. Nasal CT is required before surgery.

Other conditions such as hiatal hernia, gastric reflux, tracheal collapse, bronchial collapse, pharyngeal hyperplasia and cardiac disease secondary to increased pulmonary resistance may also occur - especially if corrective treatment is delayed.

Stenotic nares can be easily diagnosed on physical examination however definitive diagnosis of the other aspects of brachycephalic airway syndrome requires visual assessment under anaesthesia

Following assessment, we prefer to proceed with surgical correction of any abnormalities present at this time under the same anaesthetic. Soft palate shortening (staphylectomy) may be combined with thinning (palatoplasty) to remove excess tissue, everted laryngeal saccules and tonsils are assessed and treated as appropriate. Stenotic nares are also opened / widened

Post-operative care:
Patients are monitored closely after surgery to ensure that no complications arise, however, we like to get them home as soon as possible to help reduce their stress and anxiety. Almost all dogs could go home on the same day after full recovery from the anaesthesia. It is recommended that you closely monitor your pet for 2 to 3 days post-surgery to ensure their breathing has returned to normal.

Plastic collar (Elizabethan collar) will be placed around his/her neck to prevent self-trauma to the sutures in the nostrils.

Your pet will need to be kept calm and quiet for 2 weeks following surgery. They will need to be rested from regular exercise and taken outside only for toilet breaks. They should be kept in a cool environment in the case of hot weather. If they are normally very exuberant or like to bark a lot, they may be prescribed a mild sedative medication to aid their recovery.

Your dog will need to be fed soft food, such as tinned dog food, cooked meat, or dog kibble that has been moistened with water for 1-2 weeks. Your dog will be asked to return for a revisit appointment with the surgeon 7-10 days after surgery.

Most dogs show a dramatic improvement in their breathing and quality of life following surgery within a week. Dogs have the surgery before 2 years of age, before developing secondary airway changes have a much better outcome. If you have more questions and need a cost estimate, please call us on 59115070 to organise a consultation with the veterinary surgeon who performs the surgery at The Avenue Veterinary Clinic