Research focus: Anatomy, Soft Tissue Surgery

Brachycephalic dogs suffer from conformational changes that result in narrow airways. This is called brachycephalic obstructive airway syndrome (BOAS).

This leads to difficulties exercising, collapse, increased respiratory noise and difficulties sleeping. BOAS can compromises welfare. The anatomic changes that contribute to this include narrowed and inflexible nostrils; redundant and excessive pharyngeal tissue; overly long and thick soft palates; excessive laryngeal mucosa (laryngeal saccules); laryngeal collapse (voice box changes) and hypolpastic trachea (narrowed windpipe). Corrective airway surgery combats some of these anatomic components. Surgery usually consists of procedures to widen the nostrils (resection rhinoplasty) and reduce the length and thickness of the soft palate (partial staphylectomy) as well as surgery to remove the excess laryngeal mucosa.

It has been shown that corrective airway surgery can subjectively and objectively improve the way that individual brachycephalic dogs breathe. Corrective airway surgery has also been shown to reduced some other clinical conditions that are related to increased inspiratory pressure such as regurgitation. The improvement in regurgitation after corrective airways surgery seems to be breed dependant with the largest improvement seen in French Bulldogs.

It is not known how much the individual anatomic components contribute to brachycephalic obstructive airway syndrome (BOAS).

It has been shown that the shape of the laryngeal cartilages is different in brachycephalic dogs compared to mesocephalic dogs and these differences are thought to affect airflow. Further research is necessary to determine the anatomic differences between brachycephalic breeds as well

Published papers

Kaye BM, Rutherford L, Perridge DJ, Ter Haar G. Relationship between brachycephalic airway syndrome and gastrointestinal signs in three breeds of dog. Journal of Small Animal Practice. 2018 Nov;59(11):670-3.

Villedieu E, Rutherford L, Ter Haar G. Brachycephalic obstructive airway surgery outcome assessment using the 6-minute walk test: a pilot study. J Small Anim Pract. 2019;60(2):132‐135.

Rutherford L, Beever L, Bruce M, ter Haar G. Assessment of computed tomography derived cricoid cartilage and tracheal dimensions to evaluate degree of cricoid narrowing in brachycephalic dogs. Veterinary Radiology & Ultrasound. 2017 Nov;58(6):634-46.