Prevailing Clusters of Canine Behavioural Traits in Historical US Demand for Dog Breeds (1926–2005)

SIMPLE SUMMARY: The popularity of various breeds of dog and, by extension, the ancestors of at least a portion of the crossbred population varies over time. As pedigree dogs tend to exhibit breed-specific behaviour, the loads of both adaptive and less adaptive canine behaviours within society might also be expected to vary with trends in popularity, assuming that a breed in decline is not always replaced by increasing demand for a new similarly tempered breed. Using average breed behaviours from a large online survey of dog behaviour, we organised 82 pedigree breeds into six clusters and tracked the absolute and relative numbers of American Kennel Club registrations of breeds in these behaviour clusters in 1926–2005. Our data show that there is lability in the demand for breeds of the six behavioural clusters over time. Regardless of whether behavioural differences are causative of changes in demand or merely a consequence of it, changes in the types of behaviour in the pedigree population have implications for urban planning, the demand for dog training and veterinary behavioural services and the nature of human–canine interactions. Shifts in breed demand reveal an important aspect of canine behavioural epidemiology worthy of future study. ABSTRACT: Drawing on American Kennel Club (AKC) puppy registration numbers for approximately 82 varieties of pedigree dogs between 1926 and 2005, the current article analyses behavioural reports on 32,005 dogs of these varieties reported through the Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Cluster analysis of C-BARQ scores indicates that the 82 breeds fell into six clusters. Average scores for each of the 14 behavioural subscales and 22 miscellaneous traits in C-BARQ were calculated for each cluster, and the breeds in each cluster with average scores most similar to the cluster averages were selected as titular breeds. Titular breeds for each cluster were the Maltese terrier, the Great Dane, the Akita, the Australian shepherd, the American Staffordshire terrier, and the Weimaraner. Using the AKC data, we tracked longitudinal trends in annual registration numbers of breeds of each cluster over the period from 1926 to 2005. This period was subdivided into periods with differing overall trends by fitting natural cubic splines to the overall raw trend and considering both the spline and its derivative curves. Differences in the absolute numbers of dogs and trends in registrations over nearly 80 years were identified: an Early period (1926–1944, during which total registration numbers were very low); a Mid-Century Period (1945–1971, during which total registration numbers were tending to rise from year to year); a First Decline (1972–1979, a brief period during which registration numbers experienced a trend of more gradual decline); a Recovery (1980–1992, where registration numbers began to gradually rise again); and a Second Decline (1993–2005, a second sustained period of falling registration numbers, more dramatic than the first decline). The current article describes the ways in which the clustered behaviour of dogs associate with these trends. That said, there is no compelling evidence that shifts in the popularity within or between the clusters reflect consumer canine behavioural preferences. Understanding historic trends in the demand for certain canine behavioural traits could help veterinary and urban animal management stakeholders to anticipate future needs for education and infrastructure.