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 distinctively flat faces has concurrently led to a compression of their upper respiratory anatomy. The extent of these anatomical differences and the degree to which they cause airway obstruction is variable between breeds and individuals. Here, we’ll look at how to identify Brachycephalic Airway Syndrome (BAS) and the 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.
Diagnosing BAS is based on an assessment of the dog’s respiratory anatomy in relation to published criteria in order 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 upper airway obstruction; these include rhinoplasty, soft palate resection and removal of everted laryngeal saccules.3 There is evidence that early intervention leads to a better prognosis, since 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 these BAS patients.
1. Safe exercise
It is important to provide advice to clients for safe exercise management in dogs suffering from BAS. Overexertion and overheating can precipitate breathing problems; conversely, obesity arising from lack of exercise exacerbates airway obstruction. These dogs should not undertake strenuous outdoor exercise in hot or humid weather; owners should be encouraged to provide their dogs with alternative opportunities for moderate exercise in cool air-conditioned environments.4,5
2. 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. A low-front harness is recommended for these breeds, even if they are not showing symptoms of BAS.6
3. Hyperthermia awareness
Owners of brachycephalic breeds need to understand that their dogs may not be able to cool down by panting as effectively as other breeds do, so they should take preventive measures to protect their dogs from overheating. Advice includes avoiding outdoor activity in hot weather, checking that pavement or asphalt 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 dogs.
The degree of airway obstruction experienced by brachycephalic dogs varies widely, and not all meet the criteria for a diagnosis of BAS. As clinicians, therefore, it is important that we educate our clients on the early signs of BAS and make timely surgical and management recommendations.
1“Brachycephalic Airway Syndrome” from PetMD, petmd.com/dog/conditions/respiratory/c_multi_brachycephalic_airway_syndrome.
2Lodato DL, Hedlund CS (2012). “Brachycephalic airway syndrome: pathophysiology and diagnosis”. Compend Contin Educ Vet, 34 7, E3.
3Lodato DL, Hedlund CS. (2012). “Brachycephalic airway syndrome: management”. Compend Contin Educ Vet, 34 8, E4.
4Pink JJ, et al. “Laryngeal collapse in seven brachycephalic puppies”. J. Small Animal Practice 47.3 (2006): 131-135; and “Brachycephalic-friendly exercise ideas” from American Kennel Club, akc.org/expert-advice/dog-breeds/sports-snouts-and-extreme-weather-workout-safety-for-flat-faced-dogs/
5“Harnesses for brachycephalic breeds from WileyPup”. wileypup.com/best-harness-for-french-bulldog/