Aggression In Dogs Research Articles

Beyond Breeding: Re-Interpreting Paradigms in Domestic Dog Aggression Research

Pet dog aggression is a research theme of extreme importance since, today more than ever, caretakers have the motivation and interest to better understand and relate to their dogs. However, most of the literature exploring this theme focuses on biased views of breeding, behaviour profiles and aggression itself. That way, many studies regarding incident predictability end in the same pitfall of standardizing aggression by a single factor, like breed, instead of approaching other important factors beyond genetics and learning. In this essay, we propose a new approach to understand aggression in dogs, taking from non-dichotomous and non-urban-western views. Regarding the animal as complex developing systems, that are always shaping and being shaped by its surrounding environment. With said approach, factors such as skull morphology, size, weight, caretaker relationship and culture, should be further incorporated in research for a deeper understanding of dog aggression as a social communicative behaviour.

The Relation between Plasma Nesfatin-1 Levels and Aggressive Behavior in Pit Bull Dogs.

Aggression is a prevalent and concerning behavioral issue in dogs. Pit Bull dogs, known for their high levels of aggression, are recognized as a focus of concern in society. In our study, we aimed to investigate the behavioral characteristics of Pit Bull dogs and explore the potential roles of peptides involved in the neurobiology of aggression. Initially, female, and male dogs underwent aggression tests, and their aggression levels were categorized. Plasma nesfatin-1, serotonin, oxytocin, and dopamine levels were quantified using ELISA, with blood samples collected after a 24 h fasting period and 2 h post-refeeding. Our findings indicate that aggression in Pit Bull dogs correlates with decreased plasma nesfatin-1, serotonin, and oxytocin levels, while dopamine levels increase. The study's findings indicate that fasted dogs exhibited lower plasma levels of nesfatin-1, serotonin, and dopamine, while plasma oxytocin levels were higher. Furthermore, while the research findings do not suggest a significant relationship between the severity of aggression and the gender of the dog, male Pit Bull breeds appear to have higher plasma nesfatin-1 and serotonin levels compared to their female counterparts. The study's findings demonstrate that nesfatin-1, serotonin, oxytocin, and dopamine play pivotal roles in Pit Bull dogs' aggression, indicating potential interactions among these neuropeptides at the central nervous system level.

The trouble with a cuddle: Families’ experiences of supervising interactions between children in middle childhood and the family dog

Abstract Background: There is growing scientific interest in the benefits for children of interacting with and engaging with domestic dogs. Since the effects of such pairings on the dog are under explored, this study aimed to explore the lived experiences of family units supervising interactions between children in middle childhood (7–12) and the family dog(s). Methods: Ten families with at least one child aged 7–12 years old (mean 8.6, SD 1.6) and a family dog were recruited via social media to participate in whole family unit face-to-face semi-structured interviews. Experience of the effects of child-dog interaction (CDI) on the family dog was explored through discussion and reflections of CDIs, the dog’s responses, and how these were managed. The interviews were recorded and transcribed verbatim, and thematic analysis using a semantic approach was used to construct key themes. Results: All families reported that the most positive CDIs were of mutual play or that the dog freely approached the child with the ability to move away. This dynamic is subsequently referred to as dog freedom of choice (FOC). Most discussed experiences of dog aggression or avoidance of the child when FOC was compromised by close physical contact (CPC) from the child, such as cuddling. In most cases, the caregivers and children within the family unit were aware that the dog did not always enjoy such a CPC. However, interviewees recognised that such awareness did not always lead to cessation of the interaction. Conclusions: While shared play where FOC was supported suggested mutual benefits, CDIs perceived as expressions of affection, for example, hugs towards the family dog, may compromise dog quality of life and raise the risk of dog bites. Furthermore, a caregiver or child with conscious awareness of a dog reacting aversely to compromised FOC is not always a mechanism for ending of the interaction. This may raise questions about the efficacy of education programmes intended to raise the recognition of dog body language to change human behaviour.

'There is no reason to believe that genetics doesn't play a role in dog aggression'.

'There is no reason to believe that genetics doesn't play a role in dog aggression'.

Understanding canine aggression: Neurobiological insights for a complex behavior

The relationship between humans and dogs, as the first domesticated animals, exemplifies a significant aspect of human-animal interaction. During domestication, dogs have undergone behavioral changes to establish closer bonds with humans. However, certain dogs face challenges in fully adapting to their new environment, leading to behavioral disorders such as aggression. One of the most prevalent and dangerous behavioral problems in dogs is aggression, which poses risks to both humans and the dogs themselves, sometimes resulting in euthanasia. Canine aggression can arise from various medical and non-medical factors, including physical problems, endocrine system disorders, infectious diseases, central nervous system diseases, hereditary conditions, as well as racial or personal differences. Evaluating aggression based solely on species, breed, and sex characteristics is insufficient. Accurate diagnosis of aggressive behavior requires integrating findings from diverse diagnostic methods, including serum biochemistry, hormone analysis, urinalysis, electroencephalography, radiography, magnetic resonance tests, and behavioral assessments. However, to gain a comprehensive understanding of canine aggression, it is essential to consider the underlying pathophysiological processes and neurobiology. The management of aggressive behavior in dogs necessitates the implementation of diverse treatment strategies aimed at preventing the manifestation of undesirable behaviors. Within the realm of medical interventions, neutering and pharmacotherapy have emerged as prominent approaches. Neutering has shown effectiveness in mitigating aggression among dogs exhibiting aggressive tendencies. On the other hand, pharmacotherapy involves the utilization of complementary and suppressive pharmacological agents that target primary and intermediate components within the mechanisms underlying aggression. These components encompass neurotransmitter/neuromodulator substances, peptides, enzymes, and hormones, all of which contribute to the pathophysiological processes of aggression. Through the modulation of these factors, pharmacotherapy seeks to offer a comprehensive treatment approach for addressing aggressive behavior in dogs. This review aims to investigate the neurobiological basis of aggression in dogs, considering the underlying pathophysiological processes and the role of neurotransmitter/neuromodulator substances, neuropeptides, peptides, enzyme systems, and hormones. Accurate diagnosis and understanding of canine aggression are crucial for the development of effective medical and alternative treatment methods.

Transmission of haemotropic mycoplasma in the absence of arthropod vectors within a closed population of dogs on ectoparasiticides

Dog-infecting haemotropic mycoplasmas (haemoplasmas), such as Mycoplasmahaemocanis and Candidatus Mycoplasma haematoparvum are common blood-borne pathogens of canines that can potentially inflict a substantial burden of disease, particularly in immunosuppressed individuals. Nonetheless, the transmission of these pathogens remains debated as more evidence emerges that they may not be transmitted by vectors, but instead use alternative methods such as aggressive interactions and vertical transmission. Here, we treated forty dogs with two different topically-acting ectoparasiticide products able to prevent vector-borne pathogen infections during an 8-month community trial in Cambodia. A total absence of ectoparasites were observed at all time points, and no new infections caused by pathogens confirmed as being vectorially-transmitted were detected, i.e., Babesiavogeli, Ehrlichiacanis, Anaplasmaplatys, and Hepatozooncanis. Conversely, the number of haemoplasma infections in dogs on both ectoparasiticides rose significantly, with an incidence of 26 infections per 100 dogs at risk per year, providing strong evidence of non-vectorial transmission. Over the study period, dog aggression and fighting were frequently observed, highlighting a different potential mode of transmission. This study presents the first robust evidence that canine haemoplasmas may be transmitted without arthropod vectors drawing attention to the need for new methods to prevent their transmission.

Lack of accessibility and clarity in regulations concerning dog access to protected areas lowers public awareness

While natural protected areas are conceived for nature conservation, humans and their activities must also be considered. Conflict between the public and managers of protected areas can be minimized by regulations that clearly communicate which activities are allowed. Domestic dogs (Canis lupus familiaris) affect threatened species and impact numerous protected areas. In this study we evaluate: (1) the accessibility and clarity of regulations regarding dog access to protected areas in Argentina, (2) the public’s knowledge of these regulations, (3) the public’s expectations of the regulations (4) which institutions people consider should act when dog aggression occurs, and (5) measures suggested by people when dog aggression occurs. Poor accessibility and clarity of regulations were associated with poor public knowledge of them; there was also an association between visited protected areas that did not mention regulations and respondents who reported not knowing whether dogs were allowed or thinking dogs were allowed. In general, the respondents supported measures to regulate dog access to protected areas and the control of problematic dogs. We discuss several aspects that lead to a lack of clarity on dog regulations in protected areas and suggest approaches that could be used to overcome this conservation problem.

Network analysis reveals abnormal functional brain circuitry in anxious dogs.

Anxiety is a common disease within human psychiatric disorders and has also been described as a frequently neuropsychiatric problem in dogs. Human neuroimaging studies showed abnormal functional brain networks might be involved in anxiety. In this study, we expected similar changes in network topology are also present in dogs. We performed resting-state functional MRI on 25 healthy dogs and 13 patients. The generic Canine Behavioral Assessment & Research Questionnaire was used to evaluate anxiety symptoms. We constructed functional brain networks and used graph theory to compare the differences between two groups. No significant differences in global network topology were found. However, focusing on the anxiety circuit, global efficiency and local efficiency were significantly higher, and characteristic path length was significantly lower in the amygdala in patients. We detected higher connectivity between amygdala-hippocampus, amygdala-mesencephalon, amygdala-thalamus, frontal lobe-hippocampus, frontal lobe-thalamus, and hippocampus-thalamus, all part of the anxiety circuit. Moreover, correlations between network metrics and anxiety symptoms were significant. Altered network measures in the amygdala were correlated with stranger-directed fear and excitability; altered degree in the hippocampus was related to attachment/attention seeking, trainability, and touch sensitivity; abnormal frontal lobe function was related to chasing and familiar dog aggression; attachment/attention seeking was correlated with functional connectivity between amygdala-hippocampus and amygdala-thalamus; familiar dog aggression was related to global network topology change. These findings may shed light on the aberrant topological organization of functional brain networks underlying anxiety in dogs.

Puppies Raised during the COVID-19 Lockdown Showed Fearful and Aggressive Behaviors in Adulthood: An Italian Survey

During the COVID-19 pandemic, the Prime Minister's decree issued by the Italian government on 9 March 2020, known as "#Iorestoacasa" (I stay at home), required everyone to stay indoors, with a few exceptions, from 11 March to 3 May 2020. This decree had a substantial impact on the mental health of both people and dogs. We carried out a national survey to compare the personalities of adult dogs who were puppies in lockdown (from March to May 2020) with those of adult dogs born after that time (from June 2020 to February 2021). Our results highlighted a significant increase in personality traits related to fear and aggression in dogs who experienced lockdown restrictions during their socialization period, further confirming that the COVID-19 pandemic strongly impacted the behavioral development of dogs. Therefore, it may be advantageous for these dogs to be closely monitored by veterinary behaviorists and receive specialized behavioral rehabilitation therapy to lower the risk of episodes of aggression and fearfulness as well as to increase the wellbeing of dogs raised under social restrictions.

Scientific Validation of Cannabidiol for Management of Dog and Cat Diseases.

Cannabidiol (CBD) is a non-psychotropic phytocannabinoid of the plant Cannabis sativa L. CBD is increasingly being explored as an alternative to conventional therapies to treat health disorders in dogs and cats. Mechanisms of action of CBD have been investigated mostly in rodents and in vitro and include modulation of CB1, CB2, 5-HT, GPR, and opioid receptors. In companion animals, CBD appears to have good bioavailability and safety profile with few side effects at physiological doses. Some dog studies have found CBD to improve clinical signs associated with osteoarthritis, pruritus, and epilepsy. However, further studies are needed to conclude a therapeutic action of CBD for each of these conditions, as well as for decreasing anxiety and aggression in dogs and cats. Herein, we summarize the available scientific evidence associated with the mechanisms of action of CBD, including pharmacokinetics, safety, regulation, and efficacy in ameliorating various health conditions in dogs and cats.

Spatial patterns and risk of aggression of dogs and cats in a central township of Mexico City

Dog and cat aggressions are public health concerns associated with rabies transmission to the human population. The social and environmental conditions of marginalized and urban areas stand a risk due to people's contact with dogs. This study aimed to identify spatial patterns related to dog and cat aggression in a densely populated area in the center of Mexico City, analyzing the risk of aggression at the census unit level in the 2018–2020 triennium. This cross-sectional study was carried out in Coyoacán, in the south-central area of Mexico City's urbanized region. The total number of cases (n = 1,078) was obtained from monthly records of aggressions by dogs and cats, from the Control and Prevention of Zoonoses-Rabies Program of the Coyoacán Sanitary Jurisdiction. The information collected was related to the victims and the aggressors. Associations between the occurrence of bites and the characteristics of the victim were evaluated using a geographic information system (GIS), as well as the spatio-temporal distribution of the aggressions to the census unit level. Out of 1,078 cases reported, 977 (90.6%) were caused by dogs and 101 (9.4%) by cats, 55.1% (n = 587) occurred within the same household, and 13.7% (n = 148) were categorized as severe injuries. Adult men were the most affected group. Attacks on the street had a higher risk of resulting in a severe injury, compared to those that occurred at home (OR 1.63, 95CI 1.15 - 2.31, p <0.006). According to the standardized rate of the triennium, the values ​​ranged between 54.1 and 619 aggressions per 100,000 inhabitants, and summer was the season with a higher probability of occurrence. These results provide a basis for the analytical investigation of the spatial patterns of dog and cat aggression, highlighting the need to implement efficient surveillance systems and public health strategies.

Study on aggression in dogs in a public shelter

Assessing the behavior of a dog in a shelter is extremely important because the type of behavior can tell us if the animal can be given up for adoption, to whom it can be given up for adoption, if it cannot be given up for adoption and in which direction improvements in behavior need to be made to get it safely given up for adoption. This study aimed to assess the behavior of dogs in a public dog shelter by how a dog behaves towards a person (examiner) in a sequence of situations and to determine the number of individuals who responded with aggression. The behavior test was developed by The Rottweiler Rescue Society (Ontario, Canada) and John Rogerson, Blue Cross, Britain. Following minor modifications, has been used to examine dogs in public shelters. The test contains two additional assessment items from the article "An Evaluation of a Behavior Assessment to Determine the Suitability of Shelter Dogs for Rehoming" [1]. A total of 187 adult dogs were examined, of which 24 were identified with aggressive behavior and the types of aggression identified were dominance, interspecific, or territorial aggression. No behavioral test can show specifically how a dog will behave in a new environment, but the information obtained from the examination can indicate extreme manifestations of canine behavior, such as dominance aggression, possessive aggression, territorial aggression, and separation anxiety.

Relationships among morphological, environmental, social factors and aggressive profiles in Brazilian pet dogs

Pet dog aggression concerns both dogs and owners’ wellbeing and their relationship, since nowadays owners work to guarantee proper conditions for their dogs’ wellbeing, and to have a healthy emotional relationship with them. Aggressive behaviours often fall under the category of ‘undesired’ behaviours since they are mostly associated with negative contexts and possible bites or attack incidents. However, aggression remains an important component of dogs’ behavioural development, relying on communicative skills, and must be regarded as such if we want to understand how, why, and when it occurs in pet dogs. This study contributed to the ongoing investigation of how aggressive behaviour expression is affected by morpho-physiological, social, and physical environmental factors of dogs. We investigated aggression incidence and dog related factors through questionnaires applied to dog owners. Two questionnaires developed by our team were used to investigate dog, environment, and owner descriptive factors. To investigate aggression, we applied together the Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Dog and owner factors, and dog aggression data scores were associated through logistic regressions. Our results indicate that features such as the dog’s weight, skull morphology and sex, and socio-environmental proprieties like their owners’ gender and age, training regimen and household habitat, significantly affected the probabilities of complete absence or significant incidence of highest aggression in urban Brazilian domestic dogs. On the other hand, aggression was not associated to the Body Mass Index (BMI), a measure used in this study to represent the dog’s size. Rather than determining aggression to a single factor common to the species or specific breeds, our results reinforce how individual behaviour, combined with dogs’ unique genetics, physiology, life experiences and environmental contexts interact throughout development to produce the observed expression patterns.

Impactos de la pandemia de coronavirus en el bienestar animal

In 2020, the World Health Organization decreed a state of pandemic caused by the “new coronavirus”, Covid-19, leading to a scenario of social isolation worldwide, drastically changing the routine of human beings and, consequently, of their companion animals. In this context, the following literature review aims to carry out a compilation of research results promoted worldwide, bringing together data from several studies on the impacts caused by the coronavirus pandemic on animal well-being and behavior. In this way, it was possible to conclude that the biggest complication caused during this period was the hyper attachment and excessive dependence of the companion animals with their tutors, triggering several behavioral disorders, such as the Separation Anxiety Syndrome, especially after the normal return of the activities of the human daily life. In addition, some negative repercussions of the closeness of the human-animal relationship during this period was the significant increase in dog aggression attacks, especially against children, related to the reduction of walks and moments of rest and disconnection of the animals. Studies have also made it possible to identify risk factors related to confinement, such as less socialization and difficult access to veterinary services. Thus, it can be concluded that the mental health status of tutors has clear effects on the behavior and well-being of companion animals.

A pilot study investigating human behaviour towards DAVE (Dog Assisted Virtual Environment) and interpretation of non-reactive and aggressive behaviours during a virtual reality exploration task.

Dog aggression is a public health concern because dog bites often lead to physical and psychological trauma in humans. It is also a welfare concern for dogs. To prevent aggressive behaviours, it is important to understand human behaviour towards dogs and our ability to interpret signs of dog aggression. This poses ethical challenges for humans and dogs. The aim of this study was to introduce, describe and pilot test a virtual reality dog model (DAVE (Dog Assisted Virtual Environment)). The Labrador model has two different modes displaying aggressive and non-reactive non-aggressive behaviours. The aggressive behaviours displayed are based on the current understanding of canine ethology and expert feedback. The objective of the study was to test the recognition of dog behaviour and associated human approach and avoidance behaviour. Sixteen university students were recruited via an online survey to participate in a practical study, and randomly allocated to two experimental conditions, an aggressive followed by a non-reactive virtual reality model (group AN) or vice versa (group NA). Participants were instructed to ‘explore the area’ in each condition, followed by a survey. A Wilcoxon and Mann Whitney U test was used to compare the closest distance to the dog within and between groups respectively. Participants moved overall significantly closer to the non-reactive dog compared to the aggressive dog (p≤0.001; r = 0.8). Descriptions of the aggressive dog given by participants often used motivational or emotional terms. There was little evidence of simulator sickness and presence scores were high indicating sufficient immersion in the virtual environment. Participants appeared to perceive the dog as realistic and behaved and interacted with the dog model in a manner that might be expected during an interaction with a live dog. This study also highlights the promising results for the potential future use of virtual reality in behavioural research (i.e., human-dog interactions), education (i.e. safety around dogs) and psychological treatment (e.g. dog phobia treatment).

US Adults' Perceptions of Dog Breed Bans, Dog Aggression and Breed-Specific Laws.

Dog aggression directed towards people is a leading reason for relinquishment and a major public health hazard. In response to the threat of dog aggression and dog bites, breed-specific legislation has been introduced in numerous cities within the United States and countries throughout the world. There is limited evidence, however, to suggest that such laws are effective. This study explored, through an online, anonymous, cross-sectional survey, US residents’ views about the bite risk of common dog breeds, breed-specific legislation, and alternative options for improved public safety. A total of 586 surveys were completed by adult US residents, 48.8% female and 48.6% male. Approximately half of the respondents reported feeling that dog bites are a serious public health issue. Although 70% of respondents were opposed to a breed ban, only 56% felt that banning specific breeds creates an animal welfare issue. Females were less likely to support a ban or agree that specific breed bans improve public safety. When participants were asked to indicate their support of several alternatives to breed-specific legislation, the most frequently endorsed options included public education about animal welfare and animal behavior, and stricter leash laws. Further research pertaining to the most effective public education dissemination methods is warranted.

The utility of model dogs for assessing conspecific aggression in fighting dogs

This paper describes a study to assess the utility of a life-sized plush model dog as a screening tool for conspecific aggression in a population of dogs bred for use in dogfighting. Because the dogs in this sample experienced similar selective pressures and life histories, we hypothesized conspecific aggression, when present, would be a stable trait readily elicited by the model. Thus, we predicted that aggressive dogs would behave consistently toward both the model and live conspecifics. We tested our prediction with a sample of 292 animals (165 females and 127 males) confiscated during a large dogfighting raid. We found evidence of substantive predictive value with 75% of the dogs exhibiting aggression to the model also exhibited aggression to the same-sex stimulus dog. Similarly, sensitivity was high, with 81% of same-sex-aggressive test dogs detected by the model, indicating the model can discriminate between dogs with and without conspecific aggression. Finally, we found evidence of concurrent validity – with dogs exhibiting similar levels of aggression in all scenarios but with a significant sex*scenario interaction (p = 0.03) driven by higher level of aggression in the same-sex stimulus dog condition for male subjects. Based on our findings, we recommend using a model dog first when evaluating fight-bred dogs. If no physical aggression is exhibited to the model, or the behavior is ambiguous, the dog should be tested with a same-sex stimulus dog. Opposite-sex stimulus dogs alone are insufficient to screen for conspecific aggression because aggression is reduced in this test scenario for male subjects. Screening for conspecific aggression with model dogs does not completely eliminate the need for live conspecifics, but it substantially reduces the risk to stimulus dogs and evaluators alike by screening out the majority of extremely conspecific-aggressive animals. Using this procedure, a small number of dogs will be mistakenly identified as aggressive, but few truly aggressive dogs will be missed. This is the first in-shelter study on model validity to use a large, homogenous sample of dogs with known life histories and to report the predictive value of models to screen for conspecific aggression in fight-bred dogs. Comparisons of a canine model’s validity in other populations of dogs known to exhibit conspecific aggression are needed to determine if fight-bred populations are qualitatively different from other domestic dogs in their response to a model conspecific.

Systematic review of dog bite prevention strategies

BackgroundThe prevention of dog bites is an increasingly important public health topic, as the incidence of serious injury continues to rise.ObjectivesTo evaluate the effectiveness of interventions to prevent dog bites...

Review on Selected Aggression Causes and the Role of Neurocognitive Science in the Diagnosis.

Simple SummaryAggression in dogs is often a reason for abandonment and/or euthanasia. Recently, knowledge about aggression has been subjected to more detailed analysis. In recent years, it has been studied in terms of factors affecting it, such as diet (especially nutritional supplements) and physiology (endocrine system). In addition, recently, new methods of brain research, such as neurocognitive research, have appeared, which enable a significant increase in knowledge about dog behavior, including aggression.Aggression as a behavior is not always desirable, often ends in abandonment and/or euthanasia. However, it is possible to prevent the occurrence of unwanted aggression in domestic dogs. Aggression is not a fully understood phenomenon. In recent years, many studies have focused on the influence of diet and physiology (including the endocrine system) on the emergence of behavioral disorders. In particular, the emphasis was put on nutritional additives such as fatty acids, amino acids, and probiotics. In addition, the possibility of using neurocognition in the observation of abnormal behavior in dogs has also been discussed, which may allow for a more detailed determination of the basis of aggressive behavior in dogs. In this review, the concepts related to aggression and its potential causes have been gathered. In addition, the possible influence of diet and hormones on aggression in dogs has been discussed, as well as the application of neurocognition in the possibility of its diagnosis.

Aggression and Hypothyroidism in Dogs, an-Overview

One of the most often diagnosed endocrine disorder in middle-aged dogs is hypothyroidism. The clinicopathological aspects of the disease are well known and established by the scientific community. For over 20 years the relationship between aggression and hypothyroidism has been reported in the literature. Still the link remains speculative due to lack of overhaul scientific data. The aim of this study is to present data from the literature relating to the association of aggression with hypothyroidism in dogs.