Clinical assessment of brachycephalic airway obstructive syndrome using questionnaire and 6-minute walk test in French Bulldogs

Abstract

Brachycephalic airway obstructive syndrome (BAOS) is an anatomical abnormality of the upper airway commonly
found in brachycephalic breeds leading to clinical signs and physical capacity impairment. The purposes of this study
were to objectively assess the severity of the clinical signs and physical capacity in French Bulldogs with BAOS using
questionnaire and 6-minute walk test (6-MWT), respectively. A total of 26 French Bulldogs were enrolled in this study
and divided into a normal group (n = 7), a moderate BAOS group (n = 8) and a severe BAOS group (n = 11). After
history taking and physical examination, the questionnaire was answered by the owners and 6-MWT was performed
in all dogs. The severity of the clinical signs from the total questionnaire scores in the moderate and severe BAOS
groups were significantly higher than the normal group (P<0.05 and P<0.001, respectively). The 6-MWT distance of the
normal group (521 ± 35 m) was significantly longer than the moderate BAOS group (422 ± 37 m) and the severe BAOS
group (392 ± 50 m) (P<0.001). Serious adverse clinical signs were not found during and after 6-MWT. Moreover,
negative correlations were found between 6-MWT distance and questionnaire scores with the strongest negative
correlation with the breathing sound scores (r = -0.757, P<0.001). In conclusion, dogs with moderate to severe BAOS
had a higher severity of clinical signs with lower physical capacity compared with normal dogs, both of which could
be objectively assessed and presented as numerical data by questionnaire and 6-MWT. Thus, questionnaire and 6-MWT
can provide clinical severity in detail for BAOS management.