Human directed aggression in domestic dogs (Canis familiaris): Occurrence in different contexts and risk factors

Genetic dissection of complex behaviour traits in German Shepherd dogs

A favourable genetic structure and diversity of behavioural features highlights the potential of dogs for studying the genetic architecture of behaviour traits. However, behaviours are complex traits, which have been shown to be influenced by numerous genetic and non-genetic factors, complicating their analysis. In this study, the genetic contribution to behaviour variation in German Shepherd dogs (GSDs) was analysed using genomic approaches. GSDs were phenotyped for behaviour traits using the established Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Genome-wide association study (GWAS) and regional heritability mapping (RHM) approaches were employed to identify associations between behaviour traits and genetic variants, while accounting for relevant non-genetic factors. By combining these complementary methods we endeavoured to increase the power to detect loci with small effects. Several behavioural traits exhibited moderate heritabilities, with the highest identified for Human-directed playfulness, a trait characterised by positive interactions with humans. We identified several genomic regions associated with one or more of the analysed behaviour traits. Some candidate genes located in these regions were previously linked to behavioural disorders in humans, suggesting a new context for their influence on behaviour characteristics. Overall, the results support dogs as a valuable resource to dissect the genetic architecture of behaviour traits and also highlight the value of focusing on a single breed in order to control for background genetic effects and thus avoid limitations of between-breed analyses.

A Review of the Impact of Neuter Status on Expression of Inherited Conditions in Dogs

Gonadectomy is an important reproductive management tool employed in many countries, and is highly prevalent in the US with an estimated 85% of dogs being neutered. Despite the societal benefits in pet population control, negative associations between neuter status, and health conditions have been reported in recent years. Most particularly observed are the consequences of early age neutering. Knowing that different physiological systems rely upon gonadal steroids during development and physiological maintenance, studies have been undertaken to assess the impact of neuter status on multiple body and organ systems. For some inherited conditions, neutering is associated with an increased risk of expression. Neutering has also been associated with altered metabolism and a predisposition for weight gain in dogs, which may confound the detected risk association between neutering and disease expression. This review summarizes the effects of neutering on cancer, orthopedic, and immune disorders in the dog and also explores the potentially exacerbating factor of body weight.

Managing the Risk of Aggressive Dog Behavior: Investigating the Influence of Owner Threat and Efficacy Perceptions

Aggressive behavior in pet dogs is a serious problem for dog owners across the globe, with bite injuries representing a serious risk to both people and other dogs. The effective management of aggressive behavior in dogs represents a challenging and controversial issue. Although positive reinforcement training methods are now considered to be the most effective and humane technique to manage the risk of aggression, punishment-based methods continue to be used. Unfortunately, there has been little scientific study into the various factors influencing whether dog owners choose to use positive reinforcement techniques to manage aggression in their dogs. As such, current understanding of how best to encourage and support dog owners to use these methods remains extremely limited. This article uses a survey methodology based on protection motivation theory (PMT) to investigate the factors that influence owner use of positive reinforcement methods to manage aggressive behavior, in an attempt to understand potential barriers and drivers of use. In addition, the article provides an initial exploration of the potential role of wider psychological factors, including owner emotional state, social influence, and cognitive bias. Findings show that the perceived efficacy of positive reinforcement methods and the perceived ability of owners to effectively implement the technique are both key factors predicting future intentions and current reported use. Future interventions should focus on enhancing owner confidence in the effective use of positive reinforcement techniques across multiple scenarios, as well as helping owners manage their own emotional responses when they encounter challenging situations and setbacks.

Impact of Socio-Economic Status on Accessibility of Dog Training Classes

Simple Summary

Behaviour problems are among the most common reasons owners give for relinquishing their dog to a rehoming centre. Dog training and owner education classes can help prevent behaviour problems, but some people may not attend these due to cost and other barriers, particularly people on low incomes. This study compared the engagement of dog owners recruited in areas with high levels of socio-economic deprivation who were offered free face-to-face dog training classes or an online dog training course. The study aimed to find out whether the online or the face-to-face formats were better at reducing barriers to learning about dog behaviour. There were high dropout rates from both types of courses; none of the participants finished the online course, and 43% of people did not reach the end of the face-to-face classes. A course of paid dog training classes with similar content, running in the same geographic area, had a comparatively low dropout rate (24%). Participants who completed the free face-to-face classes had significantly higher household incomes and were less likely to receive means-tested benefits than participants who dropped out. This evidence suggests that low income dog owners may face other barriers to attending dog training classes, aside from, or in addition to, cost. Future research should investigate people’s reasons for not continuing with dog training courses in order to support the development of training and behaviour advice delivery that is accessible to everyone.

Abstract

Behaviour problems are amongst the most common reasons given for relinquishing dogs to rehoming centres. Some behaviour problems may be amenable to being tackled pre-emptively with classes educating owners on basic dog training and understanding behaviour; however, it is recognised that people with low socio-economic status (SES) may face barriers to attending classes such as affordability, variable working hours, and limited access to transport and childcare. The current study piloted free-to-use dog training and owner education classes in areas with high levels of economic deprivation, both in the traditional face-to-face format and online. It was hypothesised that providing an online dog training course may help people overcome practical barriers by allowing them to complete training modules in their own time. High dropout rates were observed in both formats (online: 100%, face-to-face: 43% dropout). A course of paid dog training classes running in the same area saw a comparatively low dropout rate (24%). Participants who completed the face-to-face classes had significantly higher household incomes and were less likely to receive means-tested benefits than participants who dropped out (household income p = 0.049; benefits status p = 0.017). This evidence suggests that people with low SES may face non-course fee-related barriers to attending dog training classes. Future research should include a qualitative investigation of people’s reasons for not continuing with dog training courses. Study findings can support the development of training and behaviour advice delivery that is accessible to people with varied socio-economic backgrounds.

Developing and Assessing the Validity of a Scale to Assess Pet Dog Quality of Life: Lincoln P-QoL

There has been little investment in exploring the impact of the child-dog relationship on the dog. Since child-dog interactions can pose potentially serious threats to a dog's physical and psychological health, as well as the wider satisfaction of the owner with their dog, we describe the development and validation of an owner-completed pet dog quality of life scale (Lincoln P-QOL), to enable professionals and families to monitor dog well-being and employ suitable interventions as required. Four-hundred and two dog-owners (194 lived with a neuro-typically developing child; 208 lived with a child with a neuro-developmental disorder) responded to an online survey. Respondents recorded whether they had observed their dog displaying any of the 22 behavioral responses which have been identified as being common in 11 child-dog interactions. These behavioral responses appeared to group into three categories of behaviors (i.e., behavioral constructs), representing Excitability, Calmness, and Fearfulness in the dog. To assess convergent validity of the quality of life scale respondents completed additional measures including, dog body condition score, health issues (incorporating psychological factors such as anxiety and physical proxies of well-being, such as skin irritations) and dog-owner relationship satisfaction. Excitability and Fearfulness constructs were associated with a negative impact on dog health and the owner-dog relationship. Calmness was associated with a positive impact on the dog-owner relationship. A range of interactions, including carefully expressed child-dog physical affection and spending quiet time together appear to had a beneficial impact on dog quality of life, whereas rough contact, child meltdowns, and grooming/bathing had a negative effect. We found little evidence to support a difference in the overall quality of life of dogs living with neuro-typically developing children compared to those with a neuro-developmental disorder. However, parents and practitioners need to be aware of the potential increased risk to dog well-being when meltdowns, grooming/bathing, and quiet time involve a child with a neuro-developmental disorder. This is the first validated scale for the assessment of dog well-being around children, additionally, the behavioral constructs identified may form the rational basis of a more general dog behavior/stress assessment tool in social situations.

Improving the Welfare of Companion Dogs-Is Owner Education the Solution?

Simple Summary

The welfare of most dogs living in homes is largely unknown. However, national surveys carried out by animal welfare charities and findings by animal welfare researchers have shown significant deterioration in some key aspects of dog welfare. For example, more dogs presenting to vets with behavioural problems, obesity, and ill-health due to poor breeding practices. This means that some dogs are suffering due to their owners’ behaviours or ownership practices. Educating dog owners as to how best to look after their dogs is, and has been seen by many, as key to improving the welfare of dogs living in homes. However, the concept of education, the context in which it occurs, and the lack of systematic evaluation of the effectiveness of education interventions means that nobody really knows if this approach works. This paper explores these concepts and draws together a wide range of sources of information to highlight some of the complexities of improving dog welfare by educating owners.

Abstract

Vets, animal welfare charities, and researchers have frequently cited educating owners as a necessity for improving the welfare of companion dogs. The assumption that improving an owner’s knowledge through an education intervention subsequently results in improvements in the welfare of the dog appears reasonable. However, the complexity of dog welfare and dog ownership and the context in which these relationships occur is rapidly changing. Psychology has demonstrated that humans are complex, with values, attitudes, and beliefs influencing our behaviours as much as knowledge and understanding. Equally, the context in which we individuals and our dogs live is rapidly changing and responding to evolving societal and cultural norms. Therefore, we seek to understand education’s effectiveness as an approach to improving welfare through exploring and understanding these complexities, in conjunction with the relevant research from the disciplines of science education and communication. We argue that well designed and rigorously evaluated education interventions can play a part in the challenge of improving welfare, but that these may have limited scope, and welfare scientists could further consider extending cross-disciplinary, cross-boundary working, and research in order to improve the welfare of companion dogs.

Human caregivers perceive racial bias in their pet dogs

Is there any empirical support for the popular stereotype that dogs are racist? As an initial inquiry into this question, we investigated whether human caregivers perceive racial bias in the behavior of their pet dogs. In 2 studies, caretakers completed explicit and implicit measures of racial preference and reported their dogs’ behavior toward White and Black people. White caretakers reported that their dogs displayed more positive behaviors toward White than Black people, and these reports of dog behaviors were significantly correlated with caretakers’ own explicit and implicit racial preferences. Increased interracial contact was associated with less reported pro-White dog behavior. Humans perceive racial biases in those around us, including our pets.

Investigating risk factors that predict a dog's fear during veterinary consultations

Attending the veterinary clinic is an integral part of the physical welfare of every companion dog. However, some dogs experience their veterinary visits negatively, which poses a risk of injury to the veterinary staff, their guardian (owner) and themselves. It may also influence the regularity of non-urgent veterinary appointments. To date there have been conflicting reports relating to the proportion of dogs that show fear during their veterinary visits. In this study, we explored the risk factors associated with fear during veterinary examination and in novel situations (including first time at the veterinary clinic) from 26,555 responses in the Canine Behavioral Assessment and Research Questionnaire database. According to their guardians, 41% of companion dogs displayed mild to moderate fearful behaviour when examined by a veterinarian, and 14% exhibited severe or extreme fear. A similar trend was observed with dogs responding fearfully when in unfamiliar situations, including the dog’s first time at the veterinary clinic. Chi-squared tests showed every bivariate relationship between fear and the environmental and demographic factors measured was significant (p < 0.05). The most important predictors of fear in a veterinary examination were, in order: the dog’s breed group (27.1%), their history of roles or activities (16.7%), where they were sourced (15.2%), their weight (12%), the age of other dogs in the household (9.5%) and dog owner experience (6.3%). However, combined these risk factors only explain a total of 7% of variance of fear observed during veterinary examination. This suggests that fear exhibited during veterinary visits is common in dogs, but that the environment or human-animal interactions are likely to contribute more to prevalence and severity of this problem than the demographic factors measured here. We conclude by highlighting opportunities for future research aimed at facilitating less stressful veterinary visits for dogs and their guardians.

On the origin of puppies: breeding and selling procedures relevant for canine behavioural development

The success of the dog as a companion animal has undeniably led to a shift in dog breeding practices. While effects of inbreeding or large-scale breeding have given rise to numerous studies about potentially related health issues, it remains unclear to what extent behavioural development of dogs is influenced. By investigating the environment of puppies while at the breeder, the authors aimed to make an inventory of current practices regarding management, socialisation and environmental learning and subsequently to identify potential differences between breeder types. The cross-sectional study, conducted during 2016, revealed considerable variability in environment among dog breeders. Small-scale breeders, and especially occasional breeders (less than 10 adult dogs on-site) provided most enrichment, both social and non-social, by, for instance, providing more outdoor access for pregnant dams and puppies or by providing access to visitors more freely. Environmental stimuli were less controlled in occasional breeders, raising the debate about quantity versus quality of stimuli at a young age. Large-scale breeders declared to screen potential owners less intensely and time to advise them was limited. To the authors' knowledge, this is the first study that compares a large number of environmental factors between the different dog breeding categories.

Insights about the Epidemiology of Dog Bites in a Canadian City Using a Dog Aggression Scale and Administrative Data

Simple Summary

Any dog is capable of biting, and dog bites can cause serious injuries to humans or other animals. To prevent dogs from biting, we need to understand the circumstances in which dog bites are most likely to occur. Once we have that information, we can act by improving public awareness and tailoring interventions to those most at risk of being injured. In this study, we assess the circumstances surrounding dog-bite injuries, by considering dog-bite severity in conjunction with information about where the incident occurred, about human victims, and about the dogs themselves. This approach was possible because The City of Calgary systematically tracks dog-bite severity. We found that from 2012–2017, the number of severe bites occurring in Calgary has fallen. That said, severe bites tended to occur in the homes where the dogs lived, and to be directed towards children and older adults. The results from our study underscore that educational communication for parents, grandparents, and other caregivers should emphasize the importance of constant supervision around dogs, including family dogs, whenever children are present. In addition, more attention should be paid to the risks that dogs pose to older adults. Failure to protect people from dog-bite injuries has implications for the dogs’ own welfare, as well as for human health. Dogs are most likely to bite when they feel insecure in the first place. Furthermore, common responses to severe dog-bite injuries in people include rehoming and euthanizing dogs.

Abstract

Dog bites are a public health concern that also implicates animal welfare, with negative outcomes such as rehoming or euthanasia for the animals responsible. Previous research has shown that the severity of dog-bite injuries reflects multiple factors, including the degree of inhibition exhibited by dogs and how people behave towards dogs. This study utilizes an objective dog bite injury assessment tool: The Dunbar aggression scale. Trained officers employed by The City of Calgary systematically use the Dunbar scale whenever investigating dog-bite complaints. We analyzed The City of Calgary’s administrative data on confirmed dog-bite injuries in people, 2012–2017, with a multivariable generalized ordered logistic regression model. Severe dog-bite injuries occurred more frequently in the family home than in any other setting. Young children, youths and older adults were at higher risk of more serious bites than adults. There has been a decreasing trend in the probability of a high or medium severity bite, and an increasing trend in the probability of a low severity bite since 2012. These results indicate that greater public awareness regarding dog-bite injuries is needed. Consideration should be given to campaigns targeted towards different demographics, including older adults, to provide an understanding of dog behaviour and to emphasize the need to supervise children closely in the presence of all dogs at all times, including family dogs in the home environment. Given that dog-bite injuries are not just a public health issue, but also an animal welfare issue, we endorse One Health responses in educational campaigns, policy development, and professional practice.

Prevalence of 25 canine behavioral problems and relevant factors of each behavior in Japan

Undesirable behaviors exhibited by dogs are called canine behavioral problems. Behavioral problems are common among dogs kept in ordinary homes; hence, veterinarians need to have sufficient knowledge of these problems, so as to advise owners. Among dogs kept in ordinary Japanese homes, only a few behaviors have been investigated regarding prevalence and relevant factors. To improve understanding of behavioral problems, a comprehensive survey is crucial. In this study, we distributed an online survey including general information and questions about 25 canine behaviors that can become problematic to owners, to investigate (1) the prevalence of behavioral problem, (2) the most common behavioral problems, and (3) the relevant factors of each behavior. We collected 2,050 valid responses. Among all dogs, 86.0% exhibited at least one behavioral problem. “Barking at noises inside the house”, “Barking at unfamiliar visitors”, and “Pica” were the most frequent behavioral problems. To reveal those factors related to the expression of each behavior, we performed multiple logistic regression analyses, with the presence of behaviors as objective variables and dogs’ general information as explanatory variables. Breed, age, the presence of other dogs in the household, sex, neutering status, source of acquisition, and type of residence were associated with 19, 16, 5, 4, 4, 4, and 1 behaviors, respectively. This study revealed the prevalence of 25 canine behavioral problems in Japan and relevant factors of each behavior. Our findings will be useful for veterinarians in advising owners about preventing behavioral problems.

Dominance in dogs as rated by owners corresponds to ethologically valid markers of dominance

Dominance is well defined in ethology, debated in psychology, and is often unclear among the dog owning public and in the press. However, to date, no study has examined how owners perceive dominance in dogs, and what different behaviours and personality types are used to describe dominant and subordinate individuals. A questionnaire study was launched to investigate the external validity of owner-derived estimates of dominance in dog dyads sharing the same household (N = 1,151). According to the owners, dogs rated as dominant (87%) have priority access to resources (resting place, food, and rewards), undertake certain tasks (defend and lead the group, bark more), display dominance (win fights, lick the other’s mouth less, and mark over the other’s urine), share certain personality traits (smarter, more aggressive and impulsive), and are older than their partner dog (all p < 0.0001). An age-related hypothesis has been suggested to explain dominance in dogs; but we found that dog age did not explain the occurrence of dominance related behaviours over the owners’ estimate of dominance status. Results suggest that owner-derived reports of dominance ranks of dogs living in multi-dog households correspond to ethologically valid behavioural markers of dominance. Size and physical condition were unrelated to the perceived dominance. Surprisingly, in mixed-sex dyads, females were more frequently rated as dominant than males, which might correspond to a higher proportion of neutered females in this subgroup. For future studies that wish to allocate dominance status using owner report, we offer a novel survey.

Survey of cat owners on features of, and preventative measures for, feline scratching of inappropriate objects: a pilot study

Objectives The objective of this study was to collect preliminary data on relevant features and preventative measures of feline inappropriate scratching. Preliminary data could then be used to inform future randomized controlled studies. Methods A paper questionnaire was distributed to 140 cat-owning clients of a small animal practice. The response rate was 82.9%. Questions related to features of inappropriate and designated items scratched, frequency of the behavior and how owners attempted to modify the behavior. The frequency of scratching was ranked and analyzed with repeated-measures models for differences between features of items. The effectiveness of techniques to modify scratching was analyzed with Student's t-tests comparing frequencies of scratching between cats of survey participants who did and did not use specific techniques. Results Scratching of inappropriate items was reported for 83.9% of cats. Most cats (81.5%) scratched chairs or other furniture and 64.1% scratched carpet. The frequency of scratching inappropriate items was significantly influenced by type and material of the items scratched, with furniture and carpet, and fabric and carpet, respectively, being scratched most often. Most cats (76.1%) had a designated scratching item. The frequency of scratching designated items was significantly influenced by type, with cats using scratching posts and other items more often than scratch pads. Owners used a variety of punishment- and reward-based techniques to stop inappropriate scratching and encourage scratching of designated items; only one technique was found to have a significant effect, with the frequency of scratching designated items being significantly lower in cats that were placed near the item. Conclusions and relevance Furniture covered with fabric was an object frequently scratched. Fabric should be further investigated as a potential material to encourage desired scratching behavior. Scratch pads appeared less desired than scratching posts. Punishment was a common strategy to deter scratching but did not appear to influence the frequency of scratching.

Behavioral and Perceptual Differences between Sexes in Dogs: An Overview

In this paper, we review the scientific reports of sex-related differences in dogs as compared to the outcomes described for wild animals. Our aim was to explore whether the differences in male and female dogs were affected by the domestication process, in which artificial selection is the main driver. For this purpose, we used information regarding personality traits, cognitive processes, and perception, for which there is a wide theoretical framework in behavioral ecology. Aggressiveness and boldness, described as a behavioral syndrome, were reported as being higher in males than females. Females also seemed more inclined to interspecific social interactions with humans in tasks that require cooperative skills, whereas males appeared more inclined to social play, thus implying different levels of social engagement between the sexes, depending on the context. Studies on cognitive processes underlined a greater flexibility in resorting to a particular navigation strategy in males. Most lateralization studies seem to support the view that males are preferentially left-handed and females are preferentially right-handed. Reports on visual focusing coherently rank females as superior in focusing on single social and physical stimuli. Only male dogs are able to discriminate kin; however, the timing of the olfactory recording in sexes is related to the stimulus relevance. Dogs are largely in line with life-history theories, which indicate that sex differences in dogs are mainly rooted in their biological and evolutionary heritage, remaining unchanged despite artificial selection. In contrast, the higher intraspecific sociability in wild male animals was not replicated in dogs.

[Responsible dog tenure in Mexico City]

[No disponible]

Online videos indicate human and dog behaviour preceding dog bites and the context in which bites occur

YouTube videos of dog bites present an unexplored opportunity to observe dog bites directly. We recorded the context of bites, bite severity, victim and dog characteristics for 143 videos and for 56 videos we coded human and dog behaviour before the bite. Perceived bite severity was derived from visual aspects of the bite. Associations between bite severity and victim, dog and context characteristics were analysed using a Bayesian hierarchical regression model. Human and dog behaviour before the bite were summarised with descriptive statistics. No significant differences in bite severity were observed between contexts. Only age of the victim was predictive of bite severity: adults were bitten more severely than infants and infants more severely than children. Non-neutral codes describing dog body posture and some displacement and appeasement behaviours increased approximately 20 seconds before the bite and humans made more tactile contacts with dogs 21 seconds before the bite. This analysis can help to improve understanding of context in which bites occur and improve bite prevention by highlighting observable human and dog behaviours occurring before the bite.

Associations between owner personality and psychological status and the prevalence of canine behavior problems

Behavioral problems are a major source of poor welfare and premature mortality in companion dogs. Previous studies have demonstrated associations between owners' personality and psychological status and the prevalence and/or severity of their dogs' behavior problems. However, the mechanisms responsible for these associations are currently unknown. Other studies have detected links between the tendency of dogs to display behavior problems and their owners' use of aversive or confrontational training methods. This raises the possibility that the effects of owner personality and psychological status on dog behavior are mediated via their influence on the owner's choice of training methods. We investigated this hypothesis in a self-selected, convenience sample of 1564 current dog owners using an online battery of questionnaires designed to measure, respectively, owner personality, depression, emotion regulation, use of aversive/confrontational training methods, and owner-reported dog behavior. Multivariate linear and logistic regression analyses identified modest, positive associations between owners' use of aversive/confrontational training methods and the prevalence/severity of the following dog behavior problems: owner-directed aggression, stranger-directed aggression, separation problems, chasing, persistent barking, and house-soiling (urination and defecation when left alone). The regression models also detected modest associations between owners' low scores on four of the 'Big Five' personality dimensions (Agreeableness, Emotional Stability, Extraversion & Conscientiousness) and their dogs' tendency to display higher rates of owner-directed aggression, stranger-directed fear, and/or urination when left alone. The study found only weak evidence to support the hypothesis that these relationships between owner personality and dog behavior were mediated via the owners' use of punitive training methods, but it did detect a more than five-fold increase in the use of aversive/confrontational training techniques among men with moderate depression. Further research is needed to clarify the causal relationship between owner personality and psychological status and the behavioral problems of companion dogs.

A case for methodological overhaul and increased study of executive function in the domestic dog (Canis lupus familiaris)

Executive function (EF) allows for self-regulation of behavior including maintaining focus in the face of distraction, inhibiting behavior that is suboptimal or inappropriate in a given context, and updating the contents of working memory. While EF has been studied extensively in humans, it has only recently become a topic of research in the domestic dog. In this paper, I argue for increased study of dog EF by explaining how it might influence the owner-dog bond, human safety, and dog welfare, as well as reviewing the current literature dedicated to EF in dogs. In "EF and its Application to "Man's Best Friend" section, I briefly describe EF and how it is relevant to dog behavior. In "Previous investigations into EF in dogs" section, I provide a review of the literature pertaining to EF in dogs, specifically tasks used to assess abilities like inhibitory control, cognitive flexibility, and working memory capacity. In "Insights and limitations of previous studies" section, I consider limitations of existing studies that must be addressed in future research. Finally, in "Future directions" section, I propose future directions for meaningful research on EF in dogs.

Rottweilers under primary veterinary care in the UK: demography, mortality and disorders

BACKGROUND

Rottweilers are reportedly predisposed to many disorders but accurate prevalence information relating to the general population are lacking. This study aimed to describe demography, mortality and commonly recorded diseases in Rottweilers under UK veterinary care. Clinical health records within the VetCompass Programme were explored for disorders recorded during 2013.

RESULTS

Rottweilers comprised 5321 (1.17%) of 455,557 dogs attending 304 clinics. Annual proportional birth rates dropped from 1.75% in 2006 to 1.07% in 2013. Median adult bodyweight overall was 44.9 kg (IQR 39.55-51.00, range 20.00-88.80). Median male adult bodyweight (48.5 kg, interquartile range [IQR] 43.0-54.0, range 20.0-88.8) was heavier than female (41.5 kg, IQR 37.0-46.4, range 21.1-73.5) (P < 0.001). Median longevity overall was 9.0 years (IQR 7.2-10.5, range 0.0-17.0). Median female longevity (9.5 years, IQR 7.8-11.0) was greater than male (8.7 years, IQR 6.8-10.1) (P = 0.002). The most common causes of death were neoplasia (33.0%), inability to stand (16.0%) and mass-associated disorder (7.1%).At least one disorder was recorded for 60.31% of Rottweilers. The most prevalent specific disorders recorded were aggression (7.46%, 95% CI 6.40-8.64), overweight/obesity (7.06%, 95% CI: 6.02-8.21), otitis externa (6.14%, 95% CI: 5.18-7.23) and degenerative joint disease (4.69%, 95% CI: 3.84-5.66). Male Rottweilers had higher prevalence than females for aggression (9.36% versus 5.47%, P = 0.001) and pyotraumatic dermatitis (4.05% versus 1.76%, P = 0.001). Aggression was more prevalent in neutered than entire females (7.5% versus 3.1%, P = 0.003) but did not differ between neutered and entire males (9.6% versus 9.0%, P = 0.773). The most frequent disorder groups were musculoskeletal (12.01%, 95% CI: 10.69-13.45), dermatological (10.96%, 95% CI: 9.69-12.35), gastro-intestinal (195, 8.87%, 95% CI: 7.72-10.14), undesirable behaviour (7.96%, 95% CI: 6.87-9.18) and neoplasia (7.96%, 95% CI: 6.87-9.18).

CONCLUSIONS

The current study assists prioritisation of health issues within Rottweilers. Rottweilers are relatively short-lived and neoplasia is a common cause of death. The most common disorders were aggression, overweight/obesity, otitis externa and degenerative joint disease. Males were significantly heavier, shorter-lived and predisposed to aggression than females. These results can alert prospective owners to potential health issues and optimise sex selection decision-making.

Are hospital emergency department visits due to dog bites associated with ambient temperature? A time-series study in Beijing, China

BACKGROUND

It is well documented that suboptimal ambient temperature is associated with cardiovascular and respiratory diseases. However, no study has examined the relation between temperature and dog bites.

OBJECTIVES

To study the association between ambient temperature and daily hospital emergency department visits due to dog bites (EDVDBs) in Beijing, China; and to explore whether the temperature-EDVDB association varies by sex and age.

METHODS

Daily EDVDBs were collected from a hospital appointed for dog bites in Beijing during 2012-2014. A quasi-Poisson regression with distributed lag non-linear model (DLNM) was employed to estimate the impact of temperature on daily EDVDBs. Stratified analysis was performed to examine the temperature-EDVDB association by sex and age-groups. Sensitivity analysis was performed to check the robustness of the results by adjusting other meteorological variables and air pollutants.

RESULTS

A total of 42,481 EDVDBs were collected, with daily cases ranged from 15 to 71. The association between temperature and EDVDBs was U-shaped, with extreme cold temperature showing a weaker, delayed and shorter effect on the risk of dog bites while the effect of extreme hot temperature being stronger, more immediate and lasting longer. Cold temperature had a greater impact on female whereas male was more sensitive to hot temperature. The temperature-EDVDB association was unapparent in the 15-21years group. The cold effect was only significant in the 0-14years group whereas all age-groups suffered from the similar heat effect except those aged 22-45years. Adjusting other meteorological variables and air pollutants did not change the results.

CONCLUSIONS

The impact of temperature on EDVDBs is U-shaped in Beijing, China which varies by sex and age. The temperature effect is independent from other meteorological variables and air pollutants.

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.

Aggressiveness as a latent personality trait of domestic dogs: Testing local independence and measurement invariance

Studies of animal personality attempt to uncover underlying or “latent” personality traits that explain broad patterns of behaviour, often by applying latent variable statistical models (e.g., factor analysis) to multivariate data sets. Two integral, but infrequently confirmed, assumptions of latent variable models in animal personality are: i) behavioural variables are independent (i.e., uncorrelated) conditional on the latent personality traits they reflect (local independence), and ii) personality traits are associated with behavioural variables in the same way across individuals or groups of individuals (measurement invariance). We tested these assumptions using observations of aggression in four age classes (4–10 months, 10 months–3 years, 3–6 years, over 6 years) of male and female shelter dogs (N = 4,743) in 11 different contexts. A structural equation model supported the hypothesis of two positively correlated personality traits underlying aggression across contexts: aggressiveness towards people and aggressiveness towards dogs (comparative fit index: 0.96; Tucker-Lewis index: 0.95; root mean square error of approximation: 0.03). Aggression across contexts was moderately repeatable (towards people: intraclass correlation coefficient (ICC) = 0.479; towards dogs: ICC = 0.303). However, certain contexts related to aggressiveness towards people (but not dogs) shared significant residual relationships unaccounted for by latent levels of aggressiveness. Furthermore, aggressiveness towards people and dogs in different contexts interacted with sex and age. Thus, sex and age differences in displays of aggression were not simple functions of underlying aggressiveness. Our results illustrate that the robustness of traits in latent variable models must be critically assessed before making conclusions about the effects of, or factors influencing, animal personality. Our findings are of concern because inaccurate “aggressive personality” trait attributions can be costly to dogs, recipients of aggression and society in general.

Demography and disorders of German Shepherd Dogs under primary veterinary care in the UK

BACKGROUND

The German Shepherd Dog (GSD) has been widely used for a variety of working roles. However, concerns for the health and welfare of the GSD have been widely aired and there is evidence that breed numbers are now in decline in the UK. Accurate demographic and disorder data could assist with breeding and clinical prioritisation. The VetCompassTM Programme collects clinical data on dogs under primary veterinary care in the UK. This study included all VetCompassTM dogs under veterinary care during 2013. Demographic, mortality and clinical diagnosis data on GSDs were extracted and reported.

RESULTS

GSDs dropped from 3.5% of the annual birth cohort in 2005 to 2.2% in 2013. The median longevity of GSDs was 10.3 years (IQR 8.0-12.1, range 0.2-17.0). The most common causes of death were musculoskeletal disorder (16.3%) and inability to stand (14.9%). The most prevalent disorders recorded were otitis externa (n = 131, 7.89, 95% CI: 6.64-9.29), osteoarthritis (92, 5.54%, 95% CI: 4.49-6.75), diarrhoea (87, 5.24%, 95% CI: 4.22-6.42), overweight/obesity (86, 5.18%, 95% CI: 4.16-6.36) and aggression (79, 4.76%, 95% CI: 3.79-5.90).

CONCLUSIONS

This study identified that GSDs have been reducing in numbers in the UK in recent years. The most frequent disorders in GSDs were otitis externa, osteoarthritis, diarrhoea, overweight/obesity and aggression, whilst the most common causes of death were musculoskeletal disorders and inability to stand. Aggression was more prevalent in males than in females. These results may assist veterinarians to offer evidence-based advice at a breed level and help to identify priorities for GSD health that can improve the breed's health and welfare.

Escape rates and biting histories of dogs confined to their owner's property through the use of various containment methods

OBJECTIVE To determine escape rates for dogs confined to their owner's property by various containment methods and determine whether biting history was associated with containment method. DESIGN Cross-sectional survey. SAMPLE 974 owners of 1,053 dogs. PROCEDURES Individuals patronizing pet stores in Columbus, Ohio, were recruited to complete a survey on the method they used to confine their dogs to their property and their dogs' behavior history. RESULTS Dogs were confined to their owner's property by a physical fence (821/1,053 [78.0%]), electronic fence (150/1,053 [14.2%]), or tether system (82/1,053 [7.8%]). Dogs confined by an electronic fence were more likely to have escaped (66/150 [44.0%]) than were dogs confined by a see-through fence (153/658 [23.3%]), privacy fence (38/163 [23.3%]), or tether (22/82 [26.8%]). Forty-eight (4.6%) dogs had reportedly bitten a person in the past, and 81 (7.7%) had reportedly bitten another dog, but containment method was not significantly associated with whether dogs had ever bitten a person or another dog. Greeting behavior (growling, snarling, or trying to bite) was significantly associated with a history of biting a person or another dog. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that escape rate, but not biting history, was associated with the method owners used to confine dogs to their properties. Greeting behavior was associated with biting history, suggesting that owners of dogs that growl, snarl, or attempt to bite when meeting an unfamiliar person or dog should seek assistance to prevent future bites.

Correlation of neuter status and expression of heritable disorders

BACKGROUND

Gonadectomy, or neutering, is a very common surgery for dogs having many positive effects on behavior, health, and longevity. There are also certain risks associated with neutering including the development of orthopedic conditions, cognitive decline, and a predisposition to some neoplasias. This study was designed specifically to identify if a correlation exists between neuter status and inherited conditions in a large aggregate cohort of dogs representing many different breeds.

RESULTS

Neutered dogs were at less risk for early and congenital conditions (aortic stenosis, early onset cataracts, mitral valve disease, patent ductus arteriosus, portosystemic shunt, and ventricular septal defect) than intact dogs. Neutering was also associated with reduced risk of dilated cardiomyopathy and gastric dilatation volvulus in males. Neutering was significantly associated with an increased risk for males and females for cancers (hemangiosarcoma, hyperadrenocorticism, lymphoma, mast cell tumor, and osteosarcoma), ruptured anterior cruciate ligament and epilepsy. Intervertebral disk disease was associated with increased risk in females only. For elbow dysplasia, hip dysplasia, lens luxation, and patellar luxation neutering had no significant effect on the risk for those conditions. Neutering was associated with a reduced risk of vehicular injury, a condition chosen as a control.

CONCLUSIONS

In this retrospective study, several conditions showed an increased risk associated with neutering whereas other conditions were less likely to be expressed in neutered dogs. The complexity of the interactions between neutering and inherited conditions underscores the need for reflective consultation between the client and the clinician when considering neutering. The convenience and advantages of neutering dogs that will not be included in a breeding program must be weighed against possible risk associated with neutering.

Factors associated with canine resource guarding behaviour in the presence of dogs: A cross-sectional survey of dog owners

Resource guarding (RG) involves the use of specific behaviour patterns to control access to an item of potential "value" (as perceived by the dog), and can be expressed in the presence of various animals, including other dogs. The current study aimed to identify factors associated with RG patterns expressed around other dogs. Dog owners (n=3068) were recruited through social media to answer questions regarding dog- and household-related factors, as well as their dog's current and past behaviour around resources in the presence of other dogs. Participants were screened for their ability to identify different forms of resource guarding from video, and were removed from the study if they incorrectly identified any of the videos provided. This resulted in a final sample of 2207 participants (n=3589 dogs). Multiple multi-level logistic regression models were developed to determine the association between independent variables of interest and RG patterns (i.e., RG aggression, avoidance, and rapid ingestion) when in the presence of other dogs. Namely, dogs living in multi-dog households were more likely to display RG aggression, avoidance, and rapid ingestion (p<0.01) compared to dogs that live without other dogs. Dogs with higher levels of impulsivity and fear were more likely to display RG aggression (p<0.001). Neutered males (p<0.01) were more likely to be RG aggressive compared to dogs of other sexes and neuter statuses. Teaching dogs to reliably "drop" items when requested was associated with a reduced likelihood of biting RG aggression (p<0.05). Distinct associative relationships between the patterns of RG in the presence of other dogs were identified. Dogs that express RG aggression were less likely to express RG avoidance or RG rapid ingestion; however, the latter two types were likely to co-occur, perhaps dependent on the type of resource involved. This suggests that dogs may be relatively more fixed in their action around items in the presence of dogs. However, a longitudinal study is important to determine the exact nature of relationships between RG patterns. The results identified in this study can be used as a basis for further investigation on factors influencing RG behaviour in the presence of other dogs.

Factors associated with canine resource guarding behaviour in the presence of people: A cross-sectional survey of dog owners

Resource guarding (RG) involves the use of specific behaviour patterns to control access to an item of potential "value" to the dog. Of particular concern are patterns involving aggression, due to safety concerns, but other patterns of RG behaviour are prevalent and include avoidance (i.e., positioning of the head or body to maintain item control, or location change with the item) and rapid ingestion (i.e., rapid ingestion of a consumable item). Current research has not investigated the etiology of RG aggression in depth, nor have the additional patterns of resource guarding been considered. Dog owners (n=3068) were recruited through social media to answer questions regarding dog- and household-related factors, as well as their dog's current and past behaviour around resources in the presence of people. Participants were screened for their ability to identify different forms of resource guarding from video, and were removed from the study if they incorrectly identified any of the videos provided. This resulted in a final sample of 2207 participants representing information for 3589 dogs. Multiple multi-level logistic regression models were developed to determine the association between independent variables of interest and each pattern of resource guarding. Dogs with higher levels of impulsivity were more likely to display avoidance, rapid ingestion and aggressive RG (p<0.001), and dogs with higher levels of fearfulness were also more likely to display RG aggression (p<0.001). Neutered males (p<0.01) and mixed breeds (p<0.05) were more likely to be RG aggressive compared to dogs of other sexes, neuter statuses, and breeds. Teaching dogs to reliably "drop" items when requested was associated with a reduced likelihood of RG aggression (p<0.01) and avoidance (p<0.001). Furthermore, the addition of palatable bits of food during mealtime was associated with an increased likelihood of less severe RG behaviour (p<0.01), whereas removal of the food dish during mealtime was associated with an increased likelihood of expressing more severe or frequent RG behaviours (p<0.05). Relationships between the three types of RG patterns were varied, suggesting that RG behaviour patterns are flexible when humans are involved. The results highlight various factors that might predispose dogs to RG behaviour and potential methods for prevention of RG aggression, and can serve as a basis for future longitudinal RG research to establish causation.

Mandatory desexing of dogs: one step in the right direction to reduce the risk of dog bite? A systematic review

INTRODUCTION

Preventing dog bites is an intractable problem given the complex dog bite injury environment. Desexing of dogs has the opportunity of creating a safer injury environment, given the potential links between desexing and behaviour change in dogs.

METHODS

A systematic review of the literature was conducted to examine the evidence for desexing of dogs to reduce dog bite risk within a population health paradigm. Medline and CAB Abstracts were searched for studies that reported data on the association of dog neuter status with the risk of dog bite. All definitions of dog bite were included and all empirical studies were included in the review, limited to those published in English. Quality appraisal and data extraction were based on the 2013 evidence-based practice and critical appraisal tool from the University of Auckland.

RESULTS

Five out of six observational studies, from four study populations found evidence that intact dogs were associated with an increased risk of dog bite compared with desexed dogs. The effect sizes ranged across the studies and given the heterogeneity of the studies no single effect size on the association between desexing and dog bite risk could be estimated.

CONCLUSIONS

There is consistent evidence that desexing dogs is associated with a reduced risk of dog bite, although the studies reflect association and may not be causal. Although recent publications have suggested desexing is associated with health and behavioural costs in some breeds, population level evidence supports desexed dogs having a longer lifespan, and being less likely to wander with the added benefit of reducing unwanted litters. Thus, mandatory desexing presents a possible opportunity for prevention of dog bites expanding dog bite prevention beyond an education-only approach.

Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study

BACKGROUND

Gonadectomy is one of the most common procedures performed on dogs in the United States. Neutering has been shown to reduce the risk for some diseases although recent reports suggest increased prevalence for structural disorders and some neoplasias. The relation between neuter status and autoimmune diseases has not been explored. This study evaluated the prevalence and risk of atopic dermatitis (ATOP), autoimmune hemolytic anemia (AIHA), canine myasthenia gravis (CMG), colitis (COL), hypoadrenocorticism (ADD), hypothyroidism (HYPO), immune-mediated polyarthritis (IMPA), immune-mediated thrombocytopenia (ITP), inflammatory bowel disease (IBD), lupus erythematosus (LUP), and pemphigus complex (PEMC), for intact females, intact males, neutered females, and neutered males. Pyometra (PYO) was evaluated as a control condition.

RESULTS

Patient records (90,090) from the William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis from 1995 to 2010 were analyzed in order to determine the risk of immune-mediated disease relative to neuter status in dogs. Neutered dogs had a significantly greater risk of ATOP, AIHA, ADD, HYPO, ITP, and IBD than intact dogs with neutered females being at greater risk than neutered males for all but AIHA and ADD. Neutered females, but not males, had a significantly greater risk of LUP than intact females. Pyometra was a greater risk for intact females.

CONCLUSIONS

The data underscore the importance of sex steroids on immune function emphasizing a role of these hormones on tissue self-recognition. Neutering is critically important for population control, reduction of reproductive disorders, and offers convenience for owners. Despite these advantages, the analyses of the present study suggest that neutering is associated with increased risk for certain autoimmune disorders and underscore the need for owners to consult with their veterinary practitioner prior to neutering to evaluate possible benefits and risks associated with such a procedure.