Life expectancy of mesocephalic, dolichocephalic and brachycephalic dog breeds in Switzerland

Abstract

Lifespan and time of death of dogs died in Switzerland between 2016 and 2020 were evaluated in order to increase the awareness of the public to animal welfare-related consequences of extreme brachycephalic breeding and to clarify the torture breeding problem of dogs suffering from brachycephalic obstructive airway syndrome (BOAS). Skull shape, body size, country of origin and altitude of the registered place of residence at the time of death were analysed in a set of anonymized data from the national animal database Amicus as potential factors influencing the life expectancy. Death rate during summer months and the altitude of the reported place of residence at death were analysed in relation to the skull shape to demonstrate the heat intolerance of brachycephalic dog breeds. The final dataset included 137 469 dogs. The average age of death of the study population was 11,8 years, mixed breeds reaching a higher average age of 12,4 years than purebred dogs with 11,5 years. Bodyweight classification, skull shape and the origin of the dogs had a significant effect on the average lifespan. Giant breeds reached with 9,0 years the lowest mean age compared to the other bodyweight categories. The mean life expectancy of brachycephalic dogs was 9,8 years, i.e., 2,1 and 1,7 years less than mesocephalic and dolichocephalic dogs, respectively. Brachycephalic dogs and dogs imported from abroad showed increased mortality at a young age.