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

Elucidation of the radius and ulna fracture mechanisms in toy poodle dogs using finite element analysis

Fractures occurring in the distal radius and ulna of toy breed dogs pose distinctive challenges for veterinary practitioners, requiring specialized treatment approaches primarily based on anatomical features. Finite Element Analysis (FEA) was applied to conduct numerical experiments to determine stress distribution across the bone. This methodology offers an alternative substitute for directly investigating these phenomena in living dog experiments, which could present ethical obstacles. A three-dimensional bone model of the metacarpal, carpal, radius, ulna, and humerus was reconstructed from Computed Tomography (CT) images of the toy poodle and dachshund forelimb. The model was designed to simulate the jumping and landing conditions from a vertical distance of 40 cm to the ground within a limited timeframe. The investigation revealed considerable variations in stress distribution patterns between the radius and ulna of toy poodles and dachshunds, indicating notably elevated stress levels in toy poodles compared to dachshunds. In static and dynamic stress analysis, toy poodles exhibit peak stress levels at the distal radius and ulna. The Von Mises stresses for toy poodles reach 90.07 MPa (static) and 1,090.75 MPa (dynamic) at the radius and 1,677.97 MPa (static) and 1,047.98 MPa (dynamic) at the ulna. Conversely, dachshunds demonstrate lower stress levels for 5.39 MPa (static) and 231.79 MPa (dynamic) at the radius and 390.56 MPa (static) and 513.28 MPa (dynamic) at the ulna. The findings offer valuable insights for modified treatment approaches in managing fractures in toy breed dogs, optimizing care and outcomes.

Ethical Concerns about Fashionable Dog Breeding

The historical relationship between humans and dogs has involved selective breeding for various purposes, such as hunting, guarding, and service roles. However, over time, there has been a shift in preferences from functionality to aesthetics, which has influenced the diverse sizes, shapes, and coats of dog breeds. This review looks at fashionable dog breeding and questions the ethics of prioritising looks over health and behaviour. It aims to alert potential owners, breeders, and regulators to the importance of considering a dog's overall well-being, not just its appearance, which has resulted in fad breeding, leading to genetic disorders, health issues, and a loss of biodiversity. Ethical concerns arise from breeding brachycephalic breeds with respiratory conditions, inbreeding causing inherited disorders, and overbreeding popular breeds while shelter dogs remain unadopted. Additionally, the impact of cosmetic surgeries on popular dog breeds, as well as the neglect of behavioural traits in favour of physical characteristics and strict breeding practices are also considered. The current breeding model can have a negative impact on the emotional and cognitive well-being of dogs, resulting in issues such as aggression, anxiety, and other behavioural problems that can significantly reduce their overall quality of life. Unregulated breeding practices and the demand for rare breeds can lead to illegal breeding, compromising animal welfare. Prospective owners, veterinarians, kennel clubs, and legislators all need to play a responsible role in protecting animals.

An artificial intelligence approach to predicting personality types in dogs

Canine personality and behavioural characteristics have a significant influence on relationships between domestic dogs and humans as well as determining the suitability of dogs for specific working roles. As a result, many researchers have attempted to develop reliable personality assessment tools for dogs. Most previous work has analysed dogs' behavioural patterns collected via questionnaires using traditional statistical analytic approaches. Artificial Intelligence has been widely and successfully used for predicting human personality types. However, similar approaches have not been applied to data on canine personality. In this research, machine learning techniques were applied to the classification of canine personality types using behavioural data derived from the C-BARQ project. As the dataset was not labelled, in the first step, an unsupervised learning approach was adopted and K-Means algorithm was used to perform clustering and labelling of the data. Five distinct categories of dogs emerged from the K-Means clustering analysis of behavioural data, corresponding to five different personality types. Feature importance analysis was then conducted to identify the relative importance of each behavioural variable's contribution to each cluster and descriptive labels were generated for each of the personality traits based on these associations. The five personality types identified in this paper were labelled: "Excitable/Hyperattached", "Anxious/Fearful", "Aloof/Predatory", "Reactive/Assertive", and "Calm/Agreeable". Four machine learning models including Support Vector Machine (SVM), K-Nearest Neighbour (KNN), Naïve Bayes, and Decision Tree were implemented to predict the personality traits of dogs based on the labelled data. The performance of the models was evaluated using fivefold cross validation method and the results demonstrated that the Decision Tree model provided the best performance with a substantial accuracy of 99%. The novel AI-based methodology in this research may be useful in the future to enhance the selection and training of dogs for specific working and non-working roles.

Veterinary education and experience shape beliefs about dog breeds. Part 2: Trust

Dog breed stereotypes are frequently used to inform people's expectations about canine behavior, despite evidence that breed is largely uninformative in predicting individual dog behavior. Further, these beliefs differ among populations. However, it remains unknown how ratings of warmth toward a breed are associated with ratings of other social behavioral domains, and whether differences exist between populations with varying experience with dogs. The purpose of this study was to evaluate ratings of trust and warmth among survey respondents including veterinary students, veterinary faculty and staff, undergraduates in animal-health related majors and members of the general public. Using an online survey, respondents rated their likelihood to trust a dog in varying scenarios for 10 different dog breeds. Additionally, respondents used a feelings thermometer to rate how warm or cool they felt towards each breed. Findings revealed differences in feelings thermometer and trust ratings across populations. All ratings were lower among the veterinary academic respondents compared to the general public and undergraduates. Veterinary students further along in their training, as well as undergraduates with clinical experience, reflected perceptions similar to those of the veterinary faculty and staff providing support for cultural transmission of beliefs during veterinary education and training.

Shelter dog behavior after adoption: Using the C-BARQ to track dog behavior changes through the first six months after adoption

Despite millions of dogs entering and exiting shelters annually, little is known about dog behavior long-term after adoption. Entering a shelter is stressful for dogs which may inhibit or exaggerate behavior. There is a common public sentiment that dogs have a "honeymoon period" after adoption where dogs do not show their full repertoire of behaviors, both positive and negative, until getting more comfortable in their new home. The aim of this prospective observational cohort study was to identify prevalence of and changes in behavior issues in dogs throughout the first six months following adoption. The owners of ninety-nine dogs adopted from five Ohio shelters between October 1, 2020 and June 1, 2021 were surveyed 7, 30, 90, and 180 days after adoption, using the Canine Behavioral Assessment & Research Questionnaire (C-BARQ). Owners were also asked about household changes that may affect behavior. Estimated age, sex, weight, length of shelter stay, shelter intake reason, use of gastrointestinal, antibiotic, and psychotropic medications in the shelter, whether the animal had been previously returned to the shelter, and whether the owner was a first-time dog owner, were evaluated as predictors in a mixed effect regression model of different behavior measures over time. At various timepoints, dogs showed high prevalence for stranger-directed aggression (81.7%), owner-directed aggression (32.3%), dog-directed aggression (75%), familiar dog aggression (37.8%), stranger directed fear (58.2%), nonsocial fear (95.8%), dog directed fear (80.0%) and separation-related behaviors (92.6%). Over 180 days, stranger-directed aggression, excitability, touch sensitivity, training difficulty, and chasing increased, while separation-related behaviors, attachment and attention-seeking decreased. Owners reported high satisfaction with their dogs' behavior. Use of psychotropic medications in the shelter was predictive of stranger-directed aggression and touch sensitivity at home. These findings help veterinarians and shelter professionals council owners on potential behavior changes after adoption.

Psychological Stress Is Associated with Increased Cancer Risk in Dogs

Although there is evidence that psychological stress may be associated with increased cancer risk, the effect of stress on cancer risk is difficult to study, both in humans, due to socioeconomic factors, and in animal models, due to questionable biological relevance. Here, we test whether heritable canine temperament that increases psychological stress is associated with cancer risk. The study data are breed-specific averages of incidences of multiple cancer types and of temperament classes. The latter are derived from a latent class analysis of behavioral questionnaires completed by owners (C-BARQ). We thus classified the dogs according to whether they are calm vs. reactive within and across breeds. Using meta-analysis approaches, we modeled the risk of multiple cancer types in calm vs. reactive dogs. We adjusted for breed averages of body mass and lifespan, which are common confounders that impact cancer. Our study confirms that body size has a significant effect of on risk of multiple types of cancers in dogs and shows for the first time that temperament also has a moderate effect. These findings suggest dog models of heritable psychological stress are suitable for molecular epidemiological and translational studies on its effects on cancer risk.

Comparison of behavioural tendencies between "dangerous dogs" and other domestic dog breeds - Evolutionary context and practical implications

Aggressive behaviour by dogs is a considerable social problem, but the ability to predict which individuals may have increased aggressive tendencies is very limited, restricting the development of efficient preventive measures. There is a common perception that certain breeds are more likely to exhibit aggressive behaviour, which has contributed to the introduction of breed-specific legislation. The rationale for such legislation explicitly assumes high heritability of this trait while also implying relatively little variation within breeds; these assumptions are largely untested. We compared behavioural tendencies between 8 breeds that are subject to legislation in at least one country and 17 breeds that are not subject to legislation using two validated psychometric tools: the Dog Impulsivity Assessment Scale (DIAS), which scores elements of impulsivity, including a tendency for aggressive behaviour, and Positive and Negative Activation Scale (PANAS), which scores sensitivity to positive and negative stimuli (which may trigger aggressive responses). We found that the two groups of breeds do not differ significantly in the specific DIAS factor relating to aggressive behaviour, "Aggression Threshold and Response to Novelty", or any other DIAS and PANAS factors. We found large variations in all behavioural tendencies measured by both psychometric scales within both groups and within each breed studied. Taken together, our findings indicate that breed alone is not a reliable predictor of individual behavioural tendencies, including those related to aggression, and therefore breed-specific legislation is unlikely to be an effective instrument for reducing risk.

Genome scanning of behavioral selection in a canine olfactory detection breeding cohort

Research on working dogs is growing rapidly due to increasing global demand. Here we report genome scanning of the risk of puppies being eliminated for behavioral reasons prior to entering the training phase of the US Transportation Security Administration's (TSA) canine olfactory detection breeding and training program through 2013. Elimination of dogs for behavioral rather than medical reasons was based on evaluations at three, six, nine and twelve months after birth. Throughout that period, the fostered dogs underwent standardized behavioral tests at TSA facilities, and, for a subset of tests, dogs were tested in four different environments. Using methods developed for family studies, we performed a case-control genome wide association study (GWAS) of elimination due to behavioral observation and testing results in a cohort of 528 Labrador Retrievers (2002-2013). We accounted for relatedness by including the pedigree as a covariate and maximized power by including individuals with phenotype, but not genotype, data (approximately half of this cohort). We determined genome wide significance based on Bonferroni adjustment of two quasi-likelihood score tests optimized for either small or nearly-fully penetrant effect sizes. Six loci were significant and five suggestive, with approximately equal numbers of loci for the two tests and frequencies of loci with single versus multiple mapped markers. Several loci implicate a single gene, including CHD2, NRG3 and PDE1A which have strong relevance to behavior in humans and other species. We briefly discuss how expanded studies of canine breeding programs could advance understanding of learning and performance in the mammalian life course. Although human interactions and other environmental conditions will remain critical, our findings suggest genomic breeding selection could help improve working dog populations.