Gaining a better understanding of Brachycephalic Airway Syndrome (BAS) in dogs is key to advising your clients on best management practices.
The selective breeding that has given brachycephalic breeds such as Chihuahuas, Pugs and French Bulldogs their distinctive flat faces has concurrently led to compression of the upper respiratory anatomy. The extent of these anatomical differences and the degree to which they cause airway obstruction is variable between breeds and individuals. In this article we look at how to identify Brachycephalic Airway Syndrome (BAS) and recommendations for management.
Brachycephalic Airway Syndrome
BAS is defined as airway obstruction caused by primary characteristics such as stenotic nares, soft palate elongation and hyperplasia and tracheal hypoplasia. The resultant air turbulence in the upper respiratory tract can lead to secondary abnormalities including everted laryngeal saccules and laryngeal or tracheal collapse.1,2
Patients often present with a combination of stridor, inspiratory dyspnea and exercise intolerance; in severe cases, heat stroke and episodes of cyanosis or syncope may occur, and the airway obstruction may be life-threatening.
Diagnosis of BAS is based on assessment of the respiratory anatomy in relation to published criteria to identify abnormalities; as such, the diagnosis is made by laryngoscopy and/or tracheoscopy. Surgical techniques have been developed to address several of the abnormalities associated with BAS with the aim of reducing the upper airway obstruction, including rhinoplasty, soft palate resection and removal of everted laryngeal saccules.3 There is evidence that early intervention leads to a better prognosis, as secondary laryngeal changes can be present in puppies as young as six months old.4 However, some abnormalities such as tracheal hypoplasia cannot be treated surgically, and correct management will continue to be important in BAS patients.
Management recommendations
There are a number of management recommendations we can make to our clients with brachycephalic breeds to reduce the issues associated with their respiratory anatomy.
Exercise
It is important to consider advice for safe exercise management for dogs suffering from BAS: over-exertion and overheating can precipitate breathing problems, but conversely obesity exacerbates airway obstruction. These dogs should not undertake strenuous exercise outdoors in hot or humid weather; owners should be encouraged to provide their dogs with alternative opportunities for moderate exercise in a cool air-conditioned environment.4,5
Use of a harness
A standard collar and lead can put intense pressure on the trachea and exacerbate symptoms of BAS, sometimes triggering tracheal collapse. Use of a low-front harness is recommended for these breeds, even if they are not showing symptoms of BAS.6
Hyperthermia awareness
Owners of brachycephalic breeds need to understand that their dog may not be able to cool down by panting as effectively as other breeds, and take preventative measures to protect their dog from overheating. Advice includes avoiding being outdoors in hot weather, checking the pavement is not too hot for walking barefoot, and maintaining a cool temperature within the home. Owners should also be made aware of the signs of heat stroke and the importance of acting quickly if they notice these symptoms in their dog.
Conclusion
The degree of airway obstruction experienced by brachycephalic dogs varies widely, and not all meet the criteria for diagnosis of BAS. As clinicians, it is important that we educate our clients on the early signs of BAS and make timely surgical and management recommendations.
References
1Brachycephalic Airway Syndrome from PetMD: https://www.petmd.com/dog/conditions/respiratory/c_multi_brachycephalic_airway_syndrome
2Lodato, D.L., & Hedlund, C.S. (2012). Brachycephalic airway syndrome: pathophysiology and diagnosis. Compend Contin Educ Vet, 34 7, E3.
3Lodato, D.L., & Hedlund, C.S. (2012). Brachycephalic airway syndrome: management. Compend Contin Educ Vet, 34 8, E4.
4Pink, J. J., et al. “Laryngeal collapse in seven brachycephalic puppies.” J. Small Animal Practice 47.3 (2006): 131-135.
4Brachycephalic-friendly exercise ideas from American Kennel Club: https://www.akc.org/expert-advice/dog-breeds/sports-snouts-and-extreme-weather-workout-safety-for-flat-faced-dogs/
5Harnesses for brachycephalic breeds from WileyPup: https://www.wileypup.com/best-harness-for-french-bulldog/
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