Brachycephalic obstructive airway syndrome (BOAS) is a major welfare concern in flat-faced dog breeds. As BOAS causes respiratory difficulties and exercise intolerance, it can reduce dogs’ daily quality of life (QOL). However, evaluation of QOL in dogs is difficult, and many owners perceive BOAS signs as ‘normal’ for the breed. Accelerometers that measure frequency, duration and intensity of activities can offer an objective way of evaluating dogs’ daily activity and thereby deliver potential insights into QOL. The aim of this study was to assess habitual physical activity of 48 brachycephalic and 23 non-brachycephalic dogs using accelerometers. The accelerometers were used for one week and owners filled in a questionnaire regarding their dog’s well-being and activities. Veterinary-assessed BOAS grading for brachycephalic dogs was determined. Compared with controls, more severely affected French Bulldogs and Pugs had significantly lower total activity counts and spent less time in high activity. In Pugs, mildly affected dogs were also less active, but age can be a contributing factor here, as older age decreased activity in Pugs and controls showed a wider age range. In French Bulldogs, those dogs with no or mild signs of BOAS did not differ from controls regarding their daily activity. In conclusion, accelerometers were easy to use for objective measurement of daily activity in bracycephalic dogs, although a degree of discomfort due to the collar was reported. Results showed that BOAS signs were associated with decreased habitual physical activity. These findings emphasise the importance of actions taken to reduce incidence of BOAS in brachycephalic breeds.

Brachycephalic obstructive airway syndrome (BOAS) is a major welfare problem in short-nosed breeds, such as the French Bulldog and Pug. In addition to respiratory difficulties, exercise intolerance and impaired recovery are major signs of BOAS. To select healthier breeding animals, exercise tolerance tests, such as the 1,000-m walk test, are already used in several countries for brachycephalic dogs, although evidence supporting their use is still scarce. The aims of this study were to assess the daily welfare of young, breeding-age French Bulldogs (n = 44) and Pugs (n = 51) using an owner questionnaire, and to evaluate 6-min walk test (6MWT) and 1,000-m walk test usability for differentiation between non-or mildly BOAS-affected dogs and more severely affected dogs. Only four out of 95 French Bulldog and Pug owners reported that the BOAS signs limited the daily activities of their dogs. However, according to the physical, examination-based veterinary BOAS grading, 31/95 of the dogs had moderate to severe BOAS signs. In both breeds, the more severely affected dogs performed both exercise tests more poorly than those with no or mild BOAS signs. The longer exercise, namely the 1,000-m test, seemed slightly better able at differentiating between affected dogs and less affected ones. The results of this study further support the use of exercise tests as an important part of the breeding selection in French Bulldogs and Pugs. By influencing the breed standards set by Kennel Clubs and by using breeding selection tools, the harmful impacts of brachycephaly can be diminished.

To promote successful breeding against brachycephalic obstructive airway syndrome (BOAS), it is important to assess how BOAS signs progress during young adulthood and how evaluation age and ageing affect the results of chosen breeding selection tools. The aims of this study were to assess how veterinary-assessed and owner-reported BOAS signs and exercise test results change when dogs age. Eight English Bulldogs, 25 French Bulldogs, and 31 Pugs that had undergone previous evaluation were re-examined 2— 3 years later. An owner questionnaire regarding BOAS signs, a veterinary assessment of BOAS severity, and exercise, ie walk tests were re-performed. In Pugs, both 6-min walking distance and 1,000-m time worsened and the initial evaluation age had a significant effect on the 1,000-m time. No significant changes were seen in the results of the French Bulldogs but a negative effect on the 1,000-m time was seen with weight gain. Exercise test statistics were not performed with regard to English Bulldogs due to low sample size. The veterinary-assessed BOAS severity class remained the same in the majority of dogs and the BOAS grade worsened mostly in those dogs that were initially evaluated at less than two years of age. Most owners reported no major changes in BOAS severity. BOAS grading and walk tests were easy to repeat and results remained relatively constant in dogs initially evaluated at over two years of age, supporting the use of these breeding selection tools. However, further, large-scale offspring studies are still needed.