Comparison of Behavior and Genetic Structure in Populations of Family and Kenneled Beagles

Abstract

In dogs, the social and spatial restriction associated with living in a kennel environment could lead to chronic stress and the development of abnormal behaviors ("kennel-dog syndrome"). However, little is known about how kenneled dogs differ from their conspecifics living as pets in human families. In the current study, using a test battery exposing the dogs to novel stimuli, we compared the behavior of three groups of beagles: (1) kenneled dogs living in a restricted environment with limited human contact (N = 78), (2) family dogs living in human families as pets (N = 37), and (3) adopted dogs born in the kenneled population but raised in human families (N = 13). We found one factor comprising most of the test behaviors, labeled as Responsiveness. Family dogs and adopted dogs scored higher in Responsiveness than kenneled dogs. However, 23% of the kenneled dogs were comparable to family and adopted dogs based on a cluster analysis, indicating a similar (positive) reaction to novel stimuli, while 77% of the kenneled dogs were unresponsive (mostly immobile) in at least part of the test. To assess if the behavioral difference between the family and kenneled dogs could be due to genetic divergence of these two populations and/or to lower genetic diversity of the kenneled dogs, we analyzed their genetic structure using 11 microsatellite markers. We found no significant difference between the populations in their genetic diversity (i.e., heterozygosity, level of inbreeding), nor any evidence that the family and kenneled populations originated from different genetic pools. Thus, the behavior difference between the groups more likely reflects a G × E interaction, that is, the influence of specific genetic variants manifesting under specific environmental conditions (kennel life). Nevertheless, some kenneled individuals were (genetically) more resistant to social and environmental deprivation. Selecting for such animals could strongly improve the welfare of kenneled dog populations. Moreover, exploring the genetic background of their higher resilience could also help to better understand the genetics behind stress-and fear-related behaviors.

Genetic testing of dogs predicts problem behaviors in clinical and nonclinical samples

“…Control of population structure is critical to genetic studies of domesticated species 4,21,44 . We previously mitigated the effects of population structure by using linear mixed models and multiple cohorts with partially overlapping breed makeup in the discovery GWASs 11,12 .…”

“…Breed popularity is so unbalanced that the 10 most popular breeds accounted for 50% of all 2008 AKC registrations. We cannot rule out the effects of population structure on our studies or that some behavioral variants are part of, or inextricable from, population structure 4,21,44 . However, population structure is not a critical problem here because markers that are correlated genetically are not correlated with the same traits.…”

Gut Microbiome Composition is Associated with Age and Memory Performance in Pet Dogs

“…Since laboratory dogs represent a limited sample of the natural genetic and environmental variability found in human populations and companion (or pet) dogs, the latter has gained more popularity in aging research recently [11][12][13][14][15][16][17][18]. Their behavior also differs from that of laboratory dogs [19] in ways that make the companion dog a more ecologically valid model of human aging.…”

The First Rehoming of Laboratory Beagles in Finland: The Complete Process from Socialisation Training to Follow-up

“…8 However, kennelled Beagles are more likely to show unresponsive or freezing behaviours in a new test situation than family Beagles, perhaps demonstrating the impact of environmental deprivation on fearful behaviour. 9 As a possible consequence of their lack of boldness, they can suffer from increased nervousness and neuroticism. 10 The laboratory environment is stable and controlled, lacking the diverse stimulation and refinement strategies that are found in the environment of a pet dog living in a family home.…”