07/01/2025
Sharon Powell
BRACHYCEPHALIC AIRWAY OBSTRUCTIVE SYNDROME (BAOS)
Dr. Sharon Powell
Edison Park Animal Hospital
(Article includes material from ChatGPT)
Brachycephalic airway obstructive syndrome is a common respiratory disorder that affects certain dog and cat breeds with shortened skulls and flattened faces. While these physical traits are often considered cute or desirable, they come at a significant cost to animal health. BAOS can cause chronic breathing difficulties, reduced exercise tolerance, gastrointestinal disorders and even life-threatening airway obstruction.
Common dog breeds affected include English Bulldogs, French Bulldogs, Pugs, Boston Terriers, Boxers, Shih Tzus. Common cat breeds such as Persians and Himalayans are also often affected.
BAOS is caused by a combination of anatomical abnormalities that restrict airflow in the upper respiratory tract. These abnormalities include: Stenotic Nares (narrowed or collapsed nostrils that limit airflow during inhalation), Elongated Soft Palate (the soft tissue at the back of the roof of the mouth is too long, extending into the airway and obstructing airflow to the windpipe/trachea), Everted Laryngeal Saccules (small pouches near the vocal cords that become inflamed and protrude into the airway due to increased breathing effort), Hypoplastic Trachea (a narrower-than-normal windpipe, reducing the volume of air that can pass through). These malformations cause resistance to airflow, resulting in increased respiratory effort, noise and heat intolerance.
Signs of BAOS often begin in puppyhood but worsens over time. Common symptoms include: noisy breathing, snoring or snorting (even at rest), exercise intolerance, difficulty eating or swallowing, gagging, retching, vomiting, cyanosis (blue gums/tongue during distress), collapse/fainting during exercise. Heat, high humidity, and stress can trigger a respiratory crisis.
Diagnosis typically involves a combination of: History and Physical Exam (Observation of breathing, nostril structure, exercise intolerance); Sedated Oral Exam (To assess the soft palate, laryngeal saccules); Imaging (X-rays or CT scans to assess the trachea and other internal structures); Endoscopy (in some cases, a camera is used to visualize the upper airway in better detail).
Treatment options vary depending on severity but may include weight loss, avoiding heat and stress, use of a harness instead of a collar, minimizing activity during hot and humid conditions. Corrective surgical options are often recommended to alleviate symptoms and significantly improve the pet’s quality of life. Common procedures include widening the narrowed nostrils, resecting the elongated soft palate and removing the everted laryngeal saccules. Surgical outcomes are generally good, especially when performed early.
BAOS is a lifelong condition that requires vigilant management. Dogs with advanced disease may continue to struggle, and some may develop laryngeal collapse, requiring more intensive care. With appropriate intervention and lifestyle adjustments, many dogs experience significant improvement.