Canine aggression toward family members in Spain: Clinical presentations and related factors

Variations in Canine Behavioural Characteristics across Conventional Breed Clusters and Most Common Breed-Based Public Stereotypes

Dog breeds are grouped based on scientific agreement, whether for traditional reasons or specific tasks during their domestication. Discrepancies may occur between public views of breed behaviour and actual evidence. This research aims to investigate differences in five behavioural traits (aggression towards people, aggression towards animals, fearfulness, responsiveness to training, and activity/excitability) by using the Dog Personality Questionnaire (DPQ) across six conventional groups/clusters of dog breeds (herding, hunting, guarding, companion dogs, potentially aggressive breeds, and mixed-breed dogs) and to assess hypotheses derived from common public presumptions. A cohort of 1309 dog owners sourced through diverse online platforms took part in the study. Contrary to stereotypes, the findings indicate that breeds labelled as "potentially aggressive" display lower levels of aggression compared to guarding breeds (χ2 (5) = 3.657, p = 0.041) and mixed-breeds (χ2 (5) = 3.870, p = 0.002). Additionally, mixed-breed dogs exhibited the highest levels of fearfulness among the six conventional clusters. In terms of aggression and gender, males demonstrated higher aggression levels towards both humans and animals compared to females (p = 0.001). These results challenge established assumptions and emphasise the necessity of evidence-based methodologies in the assessment of canine behaviour.

An Assessment of Scientific Evidence Relating to the Effect of Early Experience on the Risk of Human-Directed Aggression by Adult Dogs

Human-directed aggression by domestic dogs is a major worldwide public health problem. The causes of aggression are complex, and research in this area often has to balance ecological validity with pragmatic controls; accordingly, it often does not meet the thresholds for quality typically used in reviews applying a classical "evidence-based" approach. Here, we propose a method of literature assessment that makes the "best use" of available evidence to identify and synthesise evidence relating to the most likely risk factors reported in the scientific literature. We used a systematic review process to initially identify relevant literature relating to potential early life experience (i.e., in the first six months of life) risk factors in the dog for human-directed aggression in the adult animal. Fourteen papers met our initial screening process and were subsequently analysed in detail, with data extracted and effect sizes calculated where possible. This highlighted the potential importance of the source of the animal, the age at which it was rehomed, the reason for the acquisition, the experience level of the owner, the animal's socialisation experiences, the consistent husbandry and management practices, the training, the sex ratio of the litter and the history of dogs that display aggression in the pedigree as risk factors. Taken together, it seems that early experiences which limit the ability to develop effective coping strategies and routines may be particularly important. We provide guidance for the future standardised reporting of risk related to human-directed aggression by dogs to allow greater synthesis of the literature in the future.

Assessment of owner-directed aggressive behavioural tendencies of dogs in situations of possession and manipulation

Excessive aggression is a common behaviour problem in dogs that can have various destructive effects on the affected people and the implicated dog. Aggressive behaviour directed towards the owner or other family members is one of the most frequently occurring aggressive phenotypes. Here, we examine the reliability of a short questionnaire assessing aggressive behaviours by two, contextually different behavioural tests: 'take away bone' and 'roll over'. Based on dogs' behaviour in the tests, we sorted dogs (N = 93) in two groups for each test, namely a less and a more disobedient/resistant group. The two principal components obtained in our questionnaire-'obedient' and 'aggressive towards owner'-showed significant differences between the behaviour groups. While dogs in the less disobedient/resistant groups had significantly higher 'obedient' and significantly lower 'aggressive towards owner' scores, dogs in the more disobedient/resistant groups had significantly higher 'aggressive towards owner' and significantly lower 'obedient' scores. Dogs' age, sex and neuter/spay status expressed their effect through interactions. Males, young dogs and intact dogs were less 'obedient' than older ones, while resistant spayed/neutered dogs were more aggressive towards the owner. The questionnaire used is a safe, easy to deploy and time-efficient tool to reliably assess certain owner-directed aggressive tendencies of family dogs.