Brachycephalic obstructive airway syndrome (BOAS) refers to a group of conditions resulting from the abnormal conformation of dogs with short noses (brachycephalic dogs). Brachycephalic dog breeds include English and French bulldogs, Pugs, Shih-Tzus and Pekingese. Breeds with short noses have a compacted skeleton, causing a number of malformations, including in their nasal cavities, vertebrae and tails, but have normal amounts of skin and soft tissue. Their soft tissue is therefore excessive for their skeleton, explaining the amount of skin folds brachycephalic dogs have on their faces and bodies.

Similar folds and excessive soft tissue are present in the pharynx further leading to airway obstruction.

The list of the abnormalities and conditions, most commonly seen in brachycephalic dogs, can be explained by this characteristic conformation. The abnormalities below are commonly found and treated in clinical practice.

• Stenotic nares: surgical correction
• Elongated soft palate: surgical correction
• Laryngeal collapse: correction of other obstructive anomalies, tie-back
• Hypoplastic trachea: no treatment generally needed
• Bronchial collapse: medical therapy
• Enlarged tonsils
• Pharyngeal collapse
• Everted saccules : surgical removal (controversial)
• Increased nasal mucosal contact points/caudal aberrant nasal turbinated : Laser turbinectomy

Until recently, excessive and aberrant turbinates were not considered an important aspect of BOAS. Brachycephalic breeds have the same size and number of nasal turbinates in a smaller nasal cavity, resulting in increased nasal mucosal contact points and aberrant turbinates blocking the nasopharynx.¹ Despite correction of other features of BOAS, significant nasal obstruction and therefore inspiratory effort can persist in some brachycephalic breeds if these anomalies are not addressed. Laser-assisted turbinectomy for the correction of these anomalies will be discussed. Although this technique is currently poorly available in North America (performed by the author at the CHUV in St Hyacinthe), significant improvement in quality of life and respiratory scores has been noted following the procedure.^2,3 In the future, this procedure will become increasingly available and should be recommended in brachycephalic breeds in which other BOAS factors have been corrected, yet significant airway obstruction persists.

References

1.  Auger M, Alexander K, Beauchamp G, Dunn M. Use of CT to evaluate and compare nasal features in brachycephalic and normocephalic dogs. J Small Anim Pract. 2016:10:529–536.

2.  Oechtering GU, Pohl S, Sclueter C, Shuenemann R. A novel approach to brachycephalic syndrome. 2. Laser-assisted turbinectomy. Vet Surg. 2016:45;173–181.

3.  Shuenemann R, Pohl S, Oechtering GU. A novel approach to brachycephalic syndrome. 3 Isolated laser-assisted turbinectomy of aberrant caudal nasal turbinates. Vet Surg. 2016:46;32–38.