Brachycephalic Airway Obstruction Syndrome in Dogs

Brachycephalic airway obstruction syndrome impacts dogs characterized by a short nose (brachycephalic). Common breeds associated with brachycephaly include English Bulldogs, French Bulldogs, Pekingese, Boston Terriers, Boxer Dogs, Lhasa Apsos, Shih Tzus, Pugs, and Bull Mastiffs.

Anatomic Anomalies

The short facial bone and nose, coupled with an excessive amount of soft tissue, contribute to a partial obstruction of normal airflow. Primary anatomic anomalies include an elongated soft palate, stenotic nares (narrow nostrils), hypo-plastic trachea (narrow windpipe), and redundant pharyngeal tissue (excessive throat soft tissue). Affected patients may exhibit one or more of these anatomical changes.

[Image: A lateral view showing an elongated soft palate. The black line indicates the elongation, with a normal palate stopping at that line.]

[Video: Illustration of the elongated soft palate obstructing the upper respiratory pathway.]

Clinical Signs

Anatomic anomalies increase resistance in the upper respiratory airway, leading to stertorous breathing, heightened respiratory effort, exercise intolerance, or collapse, especially in warm weather. Partial occlusion of the upper respiratory airways, with the nose contributing to 80% of the airflow resistance, results in increased lung pressure. This leads to prolonged contractions of inspiratory muscles, causing elevated respiratory effort and increased lung pressure, resulting in secondary pathologies such as non-cardiogenic pulmonary oedema, larynx collapse, hiatal hernia, and gastro-oesophageal reflux.

Treatment

Surgical intervention on the upper respiratory airway not only addresses primary issues but also mitigates secondary problems. While surgery significantly enhances the quality of life, patients may continue to exhibit stertorous breathing.

Stenotic nares are easily corrected using a wedge resection technique or laser ablation. I

Post surgery breathing

Surgical Risk and Complications

The primary surgical risk involves throat swelling during the early post-operative period. Vigilant post-operative monitoring is crucial. In severe cases with breathing difficulties due to swelling, a temporary tracheostomy (windpipe hole) may be necessary to facilitate improved breathing.