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Phenotyping of Aggressive Behavior in Golden Retriever Dogs with a Questionnaire
Abstract
Reliable and valid phenotyping is crucial for our study of genetic factors underlying aggression in Golden Retriever dogs. A mail questionnaire based on the Canine Behavioral Assessment and Research Questionnaire (CBARQ; Hsu and Serpell, 2003, JAVMA 223(9):1293-1300) was used to assess behavioral phenotypes. Owners of 228 Golden Retrievers completed the questionnaire. These dogs had been referred to our clinic for aggression problems several years earlier or they were related to aggressive dogs. In this paper, three sets of results are presented, which indicate that behavior scores from the CBARQ can be applied to genetic studies. First, factor analysis demonstrated that CBARQ items can be grouped into 10 behavioral traits, including three types of aggression: stranger-directed aggression, owner-directed aggression, and dog-directed aggression. The results were remarkably similar to those reported by Hsu and Serpell. The aggression scores showed considerable variation in our dog families, which is a prerequisite for genetic studies. Second, retrospective questions enabled us to study changes in the aggressive behavior of the dogs in the course of time. After an average time interval of 4.3 years, over 50% of the dogs had become less aggressive. Third, we analyzed data obtained with an aggression test of 83 dogs. Two out of the three CBARQ aggression factors were also found in the aggression test data.
... Other authors, in turn, did not associate neutering with aggression against people of the same household [12], against other people [12], or against other dogs [1,12]. In general, other studies linked aggression to neutering [22,23,30,41]. Niepel [2] also found that 5% of females were less aggressive after neutering, whereas aggression aggravated in 4% of the females. ...
... Heidenberger & Unshelm [29] found mixed results as well: While 52.2% of the dogs were less aggressive after neutering, the behavior did not change in 21.3% and exacerbated to 25.5%. Fewer studies showed a decreased aggression of neutered females [40][41][42][43][44]. The different results for the different forms of aggression indicate a different regulation, i.a. ...
... Furthermore, it should be mentioned that neutered and intact female dogs did not differ in terms of hunting behaviour. Although in one study prey-catching behaviour could be reduced by neutering [43], other authors could not verify this connection [2,41,49,50]. Despite these studies, owners have their dogs neutered to reduce hunting behaviour [17]. ...
... Based on previous findings, it may be hypothesized that many neurotransmitters, including dopamine, glutamate, GABA and serotonin, play an important role in learning and memory in rodents, primates and insects (e.g., Drospohila melanogaster), thus demonstrating their involvement in olfactory learning (Schultz, 2002;Krashes et al., 2009;Johnson et al., 2011). Studies on the genetic basis of behaviour have focused mainly on behavioural abnormalities in dogs, e.g., aggression or activity/impulsivity, by applying candidate-gene approach to serotonergic and dopaminergic pathways (van den Berg et al., 2006;Hejjas et al., 2007;Takeuchi et al., 2009;Vage et al., 2010). Some breeds are considered better suited as detection dogs due to their better skill and expertise (Slabbert and Rasa, 1997;Helton et al., 2009). ...
... We investigated a total of 5 olfactory receptor genes: OR1P2-like, OR51H5-like, OR52N9-like, OR52P3-like, OR9S13-like which were described in our previous study (Leśniak et al., 2008), as well as the serotonergic (HTR2B-like, HTR1A-like, SLC6A4-like) and dopaminergic (DRD1-like, DRD2-like, SLC6A3-like) neurotransmitter receptor and transporter genes previously described in dogs, e.g. by Ito et al. (2004), Maejima et al. (2007) and Vage et al. (2010). All investigated genes were characterized in Table 1. ...
... Genes associated with monoamine neurotransmitters, especially those of the dopamine and serotonin systems in dogs, have been mostly investigated as causative alleles responsible for behavioural problems, e.g. aggression (Takeuchi et al., 2009;Vage et al., 2010). In an earlier study, Morrow et al. (2000) observed that activation of the mesoprefrontal dopamine neurons correlates with disturbances in working memory of laboratory rats after exposure to trimethylthiazolone (TMT), a substance isolated from fox urine. ...
The aim of this study was to identify candidate genes that could be useful predictors of better detection performance in drugs and explosives detection dogs. Single nucleotide polymorphisms in selected canine olfactory receptor genes responsible for olfactory acuity (OR1P2-like, OR51H5-like, OR52N9-like,OR52P3-like, OR9S13-like), and genes related to the serotoninergic (SLC6A4-like, HTR1A, HTR2B-like) and dopaminergic (SLC6A3-like, DRD1-like, DRD2-like) neurotransmission with a documented role in operant conditioning, were analysed. From a total of 91 certified drug and 57 explosives detection dogs, 10 individuals demonstrating the best and 10 with the poorest detection performance, as evaluated by detection speed and style of searching, were chosen for genetic studies. In this work for the first time we show that not only polymorphisms in selected canine olfactory receptor genes, but also polymorphisms in genes encoding the transporter protein for dopamine uptake or the 5-HT 2B receptor, are important for canine olfactory detection. The G allele at the OR52N9-like:c.176 A > G and OR52N9-like:c.288 T > G loci had a negative, whereas the A allele at the OR9S13-like:c.592 G > A locus had a positive, effect on the dogs' detection performance measured as mean search time and mean search style. Additionally, the presence of the C allele in the SLC6A3-like:c.181 G > C locus and the A allele in HTR2B-like:c.596 G > A locus was associated with reduced detection performance. We suggest that good candidate dogs for detection training could be chosen for military and civilian service based on favourable genotypes in the olfactory and monoamine neurotransmitter receptor genes. This, however, should be investigated further in studies, particularly using dogs with the alleles of the candidate genes we have identified as correlated with increased performance.
... So far, the C-BARQ has been used to evaluate canine behaviour and screen for appropriate temperament in dogs in guide dog programs [14,15], to identify specific behaviours related to the dogs' hormonal response to human contact [16], and even to classify behaviour phenotypes in morphological and genetic studies [17,18]. The psychometric properties of the C-BARQ have been studied in a variety of countries and validated for use in Mandarin [19], Japanese [20], Dutch [21], Swedish [11], Italian [22], Farsi [23], Latin American Spanish [24], and Brazilian Portuguese [25], making it a tool that has shown consistency and validity in assessing dog behaviour in a wide variety of cultures. Common canine behavioural problems in various populations may have common origins, or they may be unique to specific cultures; using the same validated instrument makes such comparisons possible [26]. ...
... When strangers walk past your home while your dog is outside or in the yard. 21. When an unfamiliar person tries to touch or pet the dog. ...
... The exception was the two subscales, DDA and DDF, each with 4 items loading strongly onto one factor that we renamed Dog Associated Fear/Aggression (Table 4). Although this result was similar to the results obtained by Svartberg [11], it contrasts clearly with studies carried out in other countries [19][20][21]. Portugal has only recently started to see the dog as a family member, and many dogs are still kept in yards. The importance of socializing dogs [37] is not widely acknowledged by Portuguese owners and, as a result, some dogs may show inappropriate behaviour when meeting an unfamiliar animal making the line between aggression and fear difficult to draw. ...
The human-dog relationship is thought to be the oldest domestic animal partnership. These relationships are complex and can become problematic when they become dysfunctional. The most common signs of dysfunctional human-dog partnerships are behaviour problems that, when unidentified and uncorrected, can be a clear danger to both species and the public. The Canine Behavioural Assessment and Research Questionnaire (C-BARQ) is a widely implemented instrument to evaluate dog behaviour proven to be useful across various cultures. A European Portuguese 78-item version based on the 100-item C-BARQ was developed and its psychometric properties evaluated. The resulting questionnaire has a 13-factor structure accounting for 58.42% of the total variance with Cronbach’s alpha values ranging from 0.902 and 0.721, showing excellent to respectable consistency. The original factors, Dog-Directed Aggression and Dog-Directed Fear, both loaded strongly onto a joint factor renamed Dog Associated Fear/Aggression, explaining the 13-factor structure compared to the previously found 14-factor structure. In the European Portuguese C-BARQ only two items did not load onto their expected factor. Results show that the questionnaire measures universal dog behaviours that are evident to most owners. Our results suggest that the European Portuguese version of the C-BARQ can be used to characterize the behaviour of dog populations and is adequate for use in animal shelters to help match dogs with new owners and in clinical settings to identify behaviour problems in veterinary patients before they become unmanageable. The European Portuguese C-BARQ could be of vital importance in helping to resolve behavioural problems in owned dogs before they become so serious as to lead to abandonment or euthanasia, diminishing the pressure on municipal kennels and greatly improving canine welfare.
... The factors identified in the current study are similar to those reported previously with independent datasets (Duffy and Serpell, 2012;Hsu and Serpell, 2003;Hsu and Sun, 2010;Nagasawa et al., 2011;Tamimi et al., 2015;van den Berg et al., 2006), indicating a relatively stable factor structure for CBARQ. Most importantly for the purpose of this study, the stranger-directed aggression factor was consistent across all studies. ...
... Most importantly for the purpose of this study, the stranger-directed aggression factor was consistent across all studies. The stranger fear factor was also present in a majority of the other studies (Duffy and Serpell, 2012;Hsu and Serpell, 2003;Nagasawa et al., 2011;van den Berg et al., 2006), but combined with other fear factors in some studies (Hsu and Sun, 2010;Tamimi et al., 2015). The two studies that did not find a unique stranger fear factor were conducted in Taiwan and Iran, respectively, and therefore may indicate a difference in the temperaments or circumstances of dogs raised in these countries, or differences in owners' perceptions of dog behaviour. ...
... Non-social fear was also consistent across studies, with the exception of Tamimi et al. (2015), which found that non-social fear combined with the other fear factors. Dog-directed aggression was not identified as a factor in the current study, but has previously been identified as a factor by some researchers (Duffy and Serpell, 2012;Hsu and Sun, 2010;Nagasawa et al., 2011), and was found to combine with dog-directed fear by others (Hsu and Serpell, 2003;van den Berg et al., 2006). Similar to the current study, Tamimi et al. (2015) did not identify dog-directed aggression. ...
Aggression in dogs is a safety concern both for humans and animals, and can lead to decreased animal welfare in affected dogs due to potential abuse, neglect, relinquishment or euthanasia. We examined risk factors associated with stranger-directed aggression in dogs using the previously validated, Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Results are based on participant reports of dog behaviour. Data were analyzed using mixed logistic regression, with participant ID and country as random effects. Dogs (n = 14,310) were more likely to demonstrate stranger-directed aggression if the participant rated them as mildly or severely fearful of strangers, or mildly, but not severely, fearful in non-social situations, when compared to dogs with no fear. There was an interaction between sex and neuter status, with neutered males being more likely to be aggressive than any other group. Furthermore, adult dogs were more likely to be aggressive compared to adolescents or seniors, and dogs were less likely to be aggressive if acquired as an adult when compared to being acquired as a puppy or adolescent. The random effects for country and participant were significant (p. <. 0.001) with ICCs of 0.01 (CI: 0.00-0.08) and 0.40 (CI: 0.35-0.46), respectively, indicating that there was some correlation in behaviour among dogs within the same country and owned by the same person. The moderate effect of participant suggests that household effects need to be examined further. When looking only at dogs categorized as aggressive towards strangers (n = 11,240), dogs were significantly more likely to be categorized as having severe aggression if they were male, and if the owner rated them as mildly or severely fearful of strangers, or mildly, but not severely, fearful in non-social situations, when compared to dogs with no fear. Breed group and where the dog was acquired also had an association with severe aggression. The random effects for country and participant were significant (p. <. 0.001) with ICCs of 0.06 (CI: 0.02-0.15) and 0.34 (CI: 0.22-0.48), respectively, indicating once again that there was some correlation in behaviour among dogs within the same country and owned by the same person. These results suggest that variables related to the environment, owner experience and the dog's level of fearfulness are associated with aggressive behaviour towards strangers in dogs. Therefore, it might be possible to identify dogs at risk of developing stranger-directed aggression and implement plans to prevent behavioural issues from developing.
... The use of questionnaires may facilitate early detection of behavioral problems and encourage early treatment. In addition, this questionnaire has been used to identify behavioral phenotypes in genetic studies of dog behavior (Van den Berg et al., 2006; Liinamo et al, 2007; Van Den Berg et al., 2008). The C-BARQ has (Nagasawa et al., 2011) Mandarin Chinese (Hsu and Sun, 2010), Swedish (Svartberg, 2005), and Dutch (Van Den Berg ...
... j o u r n a l v e t b e h a v i o r . c o m et al., 2006) translations which demonstrated a high degree of consistency in the underlying factor structure across geographically and culturally distinct dog populations (Svartberg, 2005; Van Den Berg et al., 2006; Hsu & Sun, 2010; Nagasawa et al., 2011). Two previous behavioral surveys conducted on dogs in Iran were based on novel questionnaires designed in situ (Khoshnegah et al., 2011; Tamimi et al., 2013) These studies, conducted in the cities of Tehran and Mashhad, reported on the number of dogs that, according to their owners, had displayed undesirable behaviors. ...
... Factor analysis was conducted on the data obtained from the translated questionnaire and subsequently nine factors were extracted that included 49 items (Table 2). This result is similar to those from studies in other countries (United States of America: Hsu and Serpell, 2003; Taiwan: Hsu and Sun, 2010; Netherlands: Van Den Berg et al., 2006; Sweden: Svartberg, 2005:Japan: Nagasawa et al., 2011), and was most pronounced for " stranger directed aggression, " " separation related behaviors, " " attachment and attention-seeking behaviors, " and " chasing. " Some differences were observed in our study. ...
... Although the criterion validity of C-BARQ has not been addressed, the construct validity was established for the first seven subscales using a sample of 200 clinical referral cases. C-BARQ has been translated into Swedish (Svartberg, 2005) and Dutch (van den Berg et al., 2006) and the reliability of the 11 subscales in both translated C-BARQ were found to be similar to those reported in . In addition, the Dutch C-BARQ item scores were subjected to exploratory factor analysis and produced factor solution similar to that in , indicating the factor structure of C-BARQ to be stable. ...
... It was revised into C-BARQ after the study, which included two new (a total of four) dog-directed fear items in order to segregate the dog-directed fear and aggression items into separate factors. The dog-directed fear items formed a distinct factor when C-BARQ was translated into Dutch and subjected to an exploratory factor analysis (van den Berg et al., 2006). Although the overall exploratory factor analysis in our study grouped dog-directed and stranger-directed fear items, they formed two distinct factors when the fearrelated items were analyzed separately. ...
... Previous studies of C-BARQ reported the painsensitivity subscale to either have low internal consistency (Cronbach a = 0.67 in ; Cronbach a = 0.60 in Svartberg, 2005) or be unstable (van den Berg et al., 2006). After adding the two new pain-sensitivity related items to the questionnaire (Table 1), the pain-sensitivity subscale was found to be stable and had acceptable internal consistency (Cronbach a = 0.74), although one of the items (dog acts anxiously or fearfully when examined or treated by a veterinarian) did not load highly on the subscale (factor loading < 0.40) and was excluded. ...
This study used The Canine Behavioral Assessment and Research Questionnaire (C-BARQ) and regression models to explore the relative importance of dog and owner characteristics, living environment and owner–dog interaction to household dogs’ aggressiveness towards strangers, owners and other dogs. Exploratory factor analysis revealed 10 interpretable factors from the Chinese translation of C-BARQ: stranger-directed aggression, owner-directed aggression, dog-directed aggression, social fear, nonsocial fear, separation-related behavior, attachment or attention-seeking behavior, trainability, excitability and pain sensitivity. The factor structure of our study largely resembled that reported in Hsu and Serpell (2003) and van den Berg et al. (2006; Dutch translation of C-BARQ). All factors of the translated C-BARQ have adequate reliability (Cronbach α: 0.74–0.93) and are thus suitable for measuring temperament traits in Taiwan's pet dogs. Intrinsic and environmental variables important to the three aggression subscales were not entirely the same, but breed (P≤0.020) and physical punishment (P≤0.053) had significant relationships with all of them. Golden Retriever scored the lowest while dogs subjected to physical reprimands scored significantly higher on aggression subscales. In addition, higher scores on stranger-directed aggression were associated (P≤0.027) with living in rural areas, in houses with yard space and with more household members and being acquired either as puppies or for guarding purposes. Higher scores on owner-directed aggression were associated (P≤0.040) with male and older dogs, being neutered/spayed, having female owners, fewer other dogs in the household and being kept outside the house. Higher scores on dog-directed aggression, on the other hand, were associated (P≤0.050) with living in houses with either yard space or more household members and with spending less time with owners. Stranger- and dog-directed aggression had more important intrinsic and environmental variables common to them than did owner-directed aggression, which suggests that aggression towards owners may be regulated by different mechanisms from aggression towards strangers and other dogs. Although no causal relationship between dog aggression and environmental variables can be implied from observational studies, the results of this and other studies lend support to the possibility of reducing dogs’ aggressive responses through proper management by owners.
... across a wide variety of populations and cultures (González-Ramírez et al., 2017;Hsu & Sun, 2010;Marshall-Pescini et al., 2008;Nagasawa et al., 2011;Rosa, Jarrel, Soares, & Paixão, 2017;Svartberg, 2005;Tamimi, Jamshidi, Serpell, Mousavi, & Ghasempourabadi, 2015;van den Berg, Schilder, de Vries, & Leeg, 2006), the C-BARQ can be widely used to help identify such dysfunction. ...
... Functional human-dog dyads can be extremely beneficial to each member of the partnership (Bennett & Rohlf, 2007;Black, 2012;Christian et al., 2014;Wells, 2011) and to society as a whole (Davis, Nattrass, O'Brien, Patronek, & MacCollin, 2004;Endenburg & van Lith, 2011;Greatbatch, Gosling, & Allen, 2015;Hart, Zaskasloff, Bryson, & Christensen, 2000), but when (Payne et al., 2015), such as husbandry choices (Kobelt et al., 2003;Tami et al., 2008) and the personality types of both partners (Dodman et al., 2018;Harvey, Craigon, Blythe, England, & Asher, 2016;Kuroshima, Hori, Inoue-Murayama, & Fujita, 2016;van den Berg et al., 2006). Since these behavioral problems are often hallmarks of dysfunctional dyads, it makes sense to think that certain factors may be more prevalent in these dyads. ...
Human–dog dyads represent a mutually beneficial partner- ship with a 16,000-year-old history. However, when this relationship becomes dysfunctional the consequences for the human, dog, and society at large can be severe. Canine members of dysfunctional dyads often display problem behaviors, such as aggression, and are frequently allowed to roam, becoming a public health concern. The cause of this dysfunction is multifactorial and includes human and canine personality factors as well as husbandry choices. By using our knowledge of these factors, there is a possibility of early identification of such pairings so that they can be corrected or even prevented. This study evaluated the factors that can contribute to the existence of dysfunctional human–dog dyads. Dog owners were asked to fill out questionnaires regarding their dog (general characteristics and the Canine Behavioral Assessment & Research Questionnaire) and themselves (general characteristics, education, family make-up, husbandry choices, and the Eysenck Personality Questionnaire-Revised). A total of 255 responses were obtained and differences between the two dyad types were found in hus- bandry choices and in both human and dog personalities. Using these factors, logistic regression was performed, and two models were obtained that could allow for the early identification of dysfunctional dyads. These models could be used to develop targeted educational programs, to better match dogs to new owners within the context of shelter medicine and help better tailor patient care in a clinical context.
... To address this issue, various studies have attempted to identify risk factors for unwanted behaviours by analysing the association between demographic factors (sex, neuter status, shape, litter size and weaning age) and management factors (training methods, housing and human contact) with dog behaviour (Blackwell et al., 2008;Casey et al., 2014;Deldalle and Gaunet, 2014;Haverbeke et al., 2008;McGreevy et al., 2013;Rooney and Cowan, 2011;Serpell and Duffy, 2016;Tiira and Lohi, 2015). Most of these studies concentrated either on single factors or multiple factors, but just one specific component of behaviour (e.g. ...
... Parthasarathy and Crowell-Davis (2006) suggest that dogs that spend more time with their owners in intensive activities may be more prone to show separation-anxiety than dogs that spend less time in intensive activities with their owners, due to a specific attachment style of the former. However, other studies showed a favourable association between the levels of daily exercise and separation anxiety (Lofgren et al., 2014;Tiira and Lohi, 2015). The variance explained for GSD Comp Separation anxiety by the associated demographic and management factors was < 3%, indicating the complex nature of this trait and that there are other unmeasured factors that influence the expression of separation anxiety, e.g., time left alone (Rehn and Keeling, 2011). ...
As companion animals, a dog's lifestyle is mainly determined by its owner. Discrepancies between the dog's preferences and the owner's lifestyle might lead to the occurrence of unwanted behaviours that affect both the owner-dog relationship and the dog's welfare. The aim of this study was to identify behavioural traits that are characteristic of German Shepherd dogs (GSDs), and to analyse the relation between behavioural traits and demographic and management factors. Dog owners from the UK and Sweden were asked to complete two surveys, the established C-BARQ behavioural survey and a lifestyle survey developed for the study. A principal component analysis was applied to determine behavioural components for GSDs. Fifteen components were found to sufficiently explain the variance in the responses to C-BARQ, with the components Stranger-directed aggression and Dog-directed aggression explaining the greatest proportion of the variance in the data (12% and 10%, respectively). Linear models were then applied to assess the relationship between behaviour components and lifestyle factors using backward elimination to identify the model that best predicted the behaviour component. The cohort (UK or Sweden) and the age of the dog were associated with the highest number of behaviour components. This study showed that various demographic and management factors were associated with the expression of behavioural traits in GSDs. Results from this analyses may help to understand the interaction between the expression of external factors and dog behavioural traits and thus, improve the well-being of dogs and owners by reducing problem behaviours.
... Although the C-BARQ has not been separately validated for use in Italy, the factor structure of the questionnaire has been shown to be highly consistent across different countries, including the USA, Japan, Taiwan, the Netherlands, Sweden, and Iran (Duffy and Serpell 2008, Hsu and Serpell 2003, Hsu and Sun 2010, Nagasawa et al. 2011, Tamimi et al. 2014, van den Berg et al. 2006, van den Berg et al. 2010. ...
... While analyses of C-BARQ data from various countries and dog populations have revealed minor differences in factor structure -most likely due to cultural influences -the overall composition of the different behavioural traits measured by the C-BARQ appears to be remarkably consistent. This suggests that these traits are common to dogs in general, rather than specific to particular populations of dogs (Duffy and Serpell 2008, Hsu and Serpell 2003, Hsu and Sun 2010, Nagasawa et al. 2011, Tamimi et al. 2014, van den Berg et al. 2006, van den Berg et al. 2010). In addition, the C-BARQ is currently the most widely used assessment tool of its kind, and it has been used previously to validate temperament and performance tests in dogs (Arvelius et al. 2014, Barnard et al. 2012, De Meester et al. 2008, Svartberg 2005). ...
Aggressiveness is reported to be the most important public health issue related to both owned and free-roaming dogs. Common approaches to assess canine aggressiveness are temperament tests. The main aim of this study was to evaluate whether one such test, the Socially Acceptable Behaviour (SAB) test, created to evaluate aggressive and fearful behaviour in dogs in the Netherlands, could be used reliably to assess dog aggression and fear in a population of owned dogs in Central Italy. Reactions to the test were recorded and compared to the owners’ perception of their dog’s aggressiveness using a validated questionnaire (C-BARQ). Dogs showing aggressive reactions during the test obtained significantly higher (more aggressive) scores on the C-BARQ subscales ‘stranger-directed aggression’ (SDA p < 0.001), ‘owner-directed aggression’ (ODA p = 0.03), and ‘familiar dog aggression’ (FDA p = 0.006), than dogs who did not react aggressively. Logistic regression analysis revealed that 7 of the SAB-subtests were predictive of the SDA score. The findings indicated that aggression directed toward unfamiliar people can be reliably assessed using the SAB test for a population of Italian pet dogs. © 2017, Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise "G.Caporale". All rights reserved.
... In contrast to ratings, which inherently involve aggregation by the observer, coding methods quantify discrete behaviors (e.g., barking) using measures such as frequency counts, duration, or latency (e.g., Batt et al., 2008;Netto and Planta, 1997). Rating and coding measures of the behavior of individual animals can often be strongly correlated (Capitanio, 1999;De Meester et al., 2008;Hewson et al., 1998;Lloyd et al., 2007;van den Berg et al., 2006;Vazire et al., 2007). Indeed, some popular assessments that use ratings, such as the Dog Mentality Assessment (Svartberg, 2002) and the Puppy Behavior Test (Campbell, 1975), have been successfully converted into a coding format (Batt et al., 2008;Beaudet et al., 1994). ...
... The correlation matrices of the BR and BC data in both test contexts were deemed appropriate (Tables 3-6 ). We determined the number of principal components to be extracted for each PCA based on a scree test, evaluation of simple and hierarchical component structure, and component interpretability (Garson, 2013;Goldberg, 2006;Zwick and Velicer, 1986). Due to potential for small sample sizes Table 2 Operational definitions of 23 behavioral codings from the Transportation Security Administration Canine Breeding and Development Center's standardized behavioral tests. ...
... The Canine Behavioural Assessment and Research Questionnaire (C-BARQ) is a validated questionnaire that has been used in several studies [32][33][34][35]. Owners assess either the frequency or severity of numerous behaviours in a variety of situations using a 5-point ordinal scale. ...
... Test-retest and inter-rater reliabilities for both C-BARQ and MCPQ-R are acceptable [36,37]. When phenotyping aggression in golden retrievers, the authors proposed C-BARQ as a useful phenotyping technique, second only to personal interview with the owner, and more reliable than battery testing [35]. ...
Canine behaviours that are both desirable and undesirable to owners have a demonstrable genetic component. Some behaviours are breed-specific, such as the livestock guarding by maremmas and flank sucking seen in Dobermanns. While the identification of genes responsible for common canine diseases is rapidly advancing, those genes underlying behaviours remain elusive. The challenges of accurately defining and measuring behavioural phenotypes remain an obstacle, and the use of variable phenotyping methods has prevented meta-analysis of behavioural studies. International standardised testing protocols and terminology in canine behavioural evaluations should facilitate selection against behavioural disorders in the modern dog and optimise breeding success and performance in working dogs. This review examines the common hurdles faced by researchers of behavioural genetics and the current state of knowledge.
... BR's, with less reliance on observer intuition to aggregate observed behaviors, are generally considered to be less subjective than SR methods, and are, as such, anecdotally considered to give more reliable information. However, both SR (Ruefenacht et al., 2002;Wilsson and Sundgren, 1997a) and BR (Svartberg and Forkman, 2002) reliability has been evaluated empirically, and results indicate that both ratings methods often correlate with behavioral codings made on the same subjects (De Meester et al., 2008;Hewson et al., 1998;van den Berg et al., 2006). What is less well known is whether different measurement methods have different degrees of predictive validity with regards to working outcomes (e.g., certification in a training program). ...
... In theory, increased generalizability or aggregation of a measure should improve its predictive validity (Epstein, 1983(Epstein, , 1984Gosling et al., 2003), however, this is also dependent on the domain breadth of the outcome measurement (i.e., a more narrow specific predictor may predict a narrow specific outcome if they both measure the same breadth or construct of interest). Both BR's (e.g., Svartberg et al., 2005) and SR's (e.g., van den Berg et al., 2006) have been used previously in studies of predicting behavior in dogs, but the relative predictive validity of the two ratings methods has not been previously compared within the same sample of dogs, which allows for a direct comparison of the predictive validity of the two methods (for an example from the primate literature, see Uher and Asendorpf, 2008). Here we performed such a direct test. ...
... Models of impulsivity in animals similarly lack a robust demonstration of test-retest reliability over long-term time frames, despite suggestions that impulsivity is a stable characteristic persisting across experiments (Zaichenko and Merzhanova 2011). Although there has been increased interest in 'animal personality', defined as 'individual differences in behaviour that are consistent across time and contexts' (Stamps and Groothuis 2010), in recent years (Réale et al. 2007), the temporal consistency of traits is often neglected, especially over long-time intervals. For instance, with one exception (van den Berg et al. 2006 on consistency of aggressive behaviour in dogs), intervals for assessing repeatability of behaviour in dogs have not exceeded 1.5 years (reviewed in Fratkin et al. 2013). ...
... These measures show a significant correlation with each other, demonstrating cross-situational consistency (Wright et al. 2012). Thus, cognitive but not motor impulsivity appears to be a stable individual characteristic in domestic dogs and can be regarded as a personality trait, being stable across time as well as across contexts (Stamps and Groothuis 2010). This highlights an important distinction between measures that simply allow differentiation between individuals (individual differences) and those relating to behavioural style with a biological basis (true personality traits, sensu Mills 2010). ...
Individual differences in impulsivity occur at a cognitive and/or behavioural level and are associated with differing life outcomes. However, there is a lack of empirical evidence to support the long-term stability of these characteristics in non-human animals. This study reports on the stability of convergent measures of impulsivity in domestic dogs assessed more than 6 years apart. Measures were (1) owner assessment by means of a questionnaire, the validated 'Dog Impulsivity Assessment Scale' (DIAS) and (2) dogs' performance in a delayed reward choice test. Dogs had 15-min free access to two food dispensers, one dispensing a piece of food immediately, the other dispensing three pieces after a delay, which increased by 1 s every other time the dogs sampled it. Maximum delay reached in this task reflects decision-making, or cognitive impulsivity, whereas the rate of extra presses on the delayed reward device during the delay can be considered as a measure of motor or behavioural impulsivity. DIAS scores were strongly and significantly correlated across years. The maximum delay reached in the behaviour test was also highly stable, whereas paw-pressing rate was uncorrelated between the years. These results demonstrate that cognitive but not motor impulsivity is highly consistent over time in dogs.
... One of the most widely used dog personality measures, the Canine Behavioral Assessment and Research Questionnaire (C-BARQ), proposes eleven different personality dimensions in companion dogs [20] and eight different personality dimensions in guide dogs [35]. These C-BARQ dimensions have demonstrated high levels of scale reliability and validity, and the instrument has been used in numerous studies across several populations of dogs3637383940. Taking a different approach, Jones and Gosling [23] used an expert-sorting procedure to classify traits identified in all previous studies of dog personality. The procedure yielded seven broad dimensions (reactivity, fearfulness, activity, sociability, responsiveness to training, submission, aggression, as well as a classification for none/other, which included traits that were not considered to be personality). ...
... The sample size of each study varied considerably, ranging from 7 dogs [59] to 938 dogs [35], with an average of 84 dogs per study. The time interval between measures across studies varied as well, ranging from 3 days [83] to 224 weeks [37], with an average interval of 21 weeks. The age at which a dog was first tested also varied considerably across studies, ranging from 3 weeks of age [84] to 296 weeks of age [85], with a mean of 49 weeks of age. ...
Personality, or consistent individual differences in behavior, is well established in studies of dogs. Such consistency implies predictability of behavior, but some recent research suggests that predictability cannot be assumed. In addition, anecdotally, many dog experts believe that 'puppy tests' measuring behavior during the first year of a dog's life are not accurate indicators of subsequent adult behavior. Personality consistency in dogs is an important aspect of human-dog relationships (e.g., when selecting dogs suitable for substance-detection work or placement in a family). Here we perform the first comprehensive meta-analysis of studies reporting estimates of temporal consistency of dog personality. A thorough literature search identified 31 studies suitable for inclusion in our meta-analysis. Overall, we found evidence to suggest substantial consistency (r = 0.43). Furthermore, personality consistency was higher in older dogs, when behavioral assessment intervals were shorter, and when the measurement tool was exactly the same in both assessments. In puppies, aggression and submissiveness were the most consistent dimensions, while responsiveness to training, fearfulness, and sociability were the least consistent dimensions. In adult dogs, there were no dimension-based differences in consistency. There was no difference in personality consistency in dogs tested first as puppies and later as adults (e.g., 'puppy tests') versus dogs tested first as puppies and later again as puppies. Finally, there were no differences in consistency between working versus non-working dogs, between behavioral codings versus behavioral ratings, and between aggregate versus single measures. Implications for theory, practice, and future research are discussed.
... However, there are reports of very aggressive Golden Retrievers (Galac and Knol 1997;Heath 1991). We recently described the behavioral phenotype of 110 Golden Retrievers referred to our clinic for aggression problems and 118 Golden Retrievers that were recruited because they were related to one or more of the aggressive dogs (van den Berg et al. 2006). The phenotypes were based on mail questionnaires and on personal interviews with dog owners. ...
... We have collected various quantitative measures of aggressiveness for the dogs (van den Berg et al. 2003aBerg et al. , 2006. In the linkage and association analysis we focused on one of these measures: the dog owners impression on human-directed aggression. ...
Aggressive behavior displays a high heritability in our study group of Golden Retriever dogs. Alterations in brain serotonin metabolism have been described in aggressive dogs before. Here, we evaluate whether four genes of the canine serotonergic system, coding for the serotonin receptors 1A, 1B, and 2A, and the serotonin transporter, could play a major role in aggression in Golden Retrievers. We performed mutation screens, linkage analysis, an association study, and a quantitative genetic analysis. There was no systematic difference between the coding DNA sequence of the candidate genes in aggressive and non-aggressive Golden Retrievers. An affecteds-only parametric linkage analysis revealed no strong major locus effect on human-directed aggression related to the candidate genes. An analysis of 41 single nucleotide polymorphisms (SNPs) in the 1 Mb regions flanking the genes in 49 unrelated human-directed aggressive and 49 unrelated non-aggressive dogs did not show association of SNP alleles, genotypes, or haplotypes with aggression at the candidate loci. We completed our analyses with a study of the effect of variation in the candidate genes on a collection of aggression-related phenotypic measures. The effects of the candidate gene haplotypes were estimated using the Restricted Maximum Likelihood method, with the haplotypes included as fixed effects in a linear animal model. We observed no effect of the candidate gene haplotypes on a range of aggression-related phenotypes, thus extending our conclusions to several types of aggressive behavior. We conclude that it is unlikely that these genes play a major role in the variation in aggression in the Golden Retrievers that we studied. Smaller phenotypic effects of these loci could not be ruled out with our sample size.
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... Some are based on the direct observation of the dog's response to several test situations [59]. Although such tests are more objective than owner-derived information, the disadvantage is that it is difficult to evoke problem behavior in a clinical setting [60]. Other methods focus on the assessment of day-to-day behavior using a questionnaire especially designed for the dog owner. ...
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.
... Perhaps unsurprisingly, comparison of C-BARQ scores across breeds has repeatedly revealed breed differences in behavior (Duffy et al. 2008;Serpell and Duffy 2014;Tonoike et al. 2015;Hare et al. 2018;Shouldice et al. 2019). The factor structure of the C-BARQ remains relatively consistent across countries, suggesting that it is a reliable and universal measure of variation in canine behavior (van den Berg et al. 2006;Hsu and Sun 2010;Nagasawa et al. 2011;Canejo-Teixeira et al. 2018). Furthermore, genetic analyses indicate that these behavioral differences are highly heritable (Zapata et al. 2016;Ilska et al. 2017;MacLean et al. 2019). ...
Behavioral traits like aggression, anxiety, and trainability differ significantly across dog breeds and are highly heritable. However, the neural bases of these differences are unknown. Here we analyzed structural MRI scans of 62 dogs in relation to breed-average scores for the 14 major dimensions in the Canine Behavioral Assessment and Research Questionnaire, a well-validated measure of canine temperament. Several behavior categories showed significant relationships with morphologically covarying gray matter networks and regional volume changes. Networks involved in social processing and the flight-or-fight response were associated with stranger-directed fear and aggression, putatively the main behaviors under selection pressure during wolf-to-dog domestication. Trainability was significantly associated with expansion in broad regions of cortex, while fear, aggression, and other “problem” behaviors were associated with expansion in distributed subcortical regions. These results closely overlapped with regional volume changes with total brain size, in striking correspondence with models of developmental constraint on brain evolution. This suggests that the established link between dog body size and behavior is due at least in part to disproportionate enlargement of later-developing regions in larger brained dogs. We discuss how this may explain the known correlation of increasing reactivity with decreasing body size in dogs.
... Owner-reported behaviour questionnaires have been used in numerous studies, with the most commonly reported questionnaire being the C-BARQ [10]. The C-BARQ has been widely used to successfully record behaviour amongst different dog populations, including shelter, working and pet dogs [16][17][18][19][20], and amongst guide dog schools [2,9]. Some studies however have suggested that the C-BARQ may be unsuitable for certain dog populations. ...
Working dog organisations regularly assess the behaviour of puppies to monitor progression. Here, we tested the predictive validity (for predicting success in guide dog training) of a shortened version of a previously developed juvenile dog behaviour questionnaire (the refined puppy walker questionnaire, r-PWQ) and compared it with the Canine Behavioral Assessment and Research Questionnaire (C-BARQ). The r-PWQ is used by Guide Dogs UK, whereas the C-BARQ was designed for pet dogs and is used by some other guide dog schools internationally. A cohort of dogs aged eight months (n = 359) were scored concurrently on the r-PWQ and C-BARQ. Analogous traits between the questionnaires were evaluated for internal consistency and association with training outcome and compared for concurrent validity. The r-PWQ was associated with training outcome for five scales (r-Excitability, Trainability, Animal Chase, r-Attachment and attention seeking and Distractibility) and the C-BARQ for two scales (Excitability and Separation-related behaviour). There were significant correlations between analogous C-BARQ and r-PWQ trait scores (p < 0.001) except for Separation-related behaviour and questionnaire scales had similar internal consistencies. The r-PWQ may be more suitable to use with guide dog schools. However, due to the correlation between analogous scales (except for “Distractibility”) some scales could be substituted for one another when reviewing the behaviour of dogs between guide dog schools using different questionnaires.
... We found that the neutered/spayed dogs scored higher on the 'playfulness' component ( Figure 2). The effect of spaying and neutering on dog behaviour is not yet clear; some studies investigating the factors affecting aggressive behaviour in dogs, for example, have found weak or no association, often confounded by the fact that, especially in male dogs, aggressiveness is often a cause of castration, rather than a consequence [21][22][23][24]. However, one study on male ferrets found that the incidence of play behaviour was significantly higher after castration [25]. ...
This study assessed the feasibility and reproducibility of a previously validated temperament test (TT) for shelter dogs. The test was developed to measure dog behaviour in the kennel, and traits of sociability towards people and other dogs, docility to leash, playfulness, cognitive skills, and reactivity. We introduced the use of differently sized fake dogs to check their appropriateness in correctly assessing sociability to dogs to broaden its applicability (as the original study used real stimulus dogs). We hypothesised that dogs’ responses may be modulated by the body size of the stimulus dog presented. The reduction analysis of the TT scores extracted five main dimensions (explaining 70.8% of variance), with high internal consistency (alpha > 0.65) and being broadly consistent with existing research. Behavioural components that were extracted from the fake dog experiment showed that dogs are likely to show signs of anxiety and fear toward both the real and fake dog. Dogs’ responses towards a real vs. fake stimulus were significantly correlated (p < 0.05) and they were not affected by the size of the stimulus (p > 0.05). We discuss the importance of interpreting these data with caution and use behavioural tests as a partial screening tool to be used in conjunction with more extensive behavioural and welfare monitoring.
... The effects of castration on aggression are particularly unclear (Hsu and Sun, 2010). Some studies found a decrease of aggression in castrated dogs (Borchelt, 1983;Gershman et al., 1994;Messam et al., 2008;Kuhne, 2012), whereas others found opposite effects Serpell, 1997a, 1997b;Guy et al., 2001;Kaufmann et al., 2017) or no significant differences at all (van den Berg et al., 2006;Bennett and Rohlf, 2007). Furthermore, one study reported that dominance aggression decreased after castration in male dogs, whereas it increased in females (Pérez-Guisado and Muñoz-Serrano, 2009). ...
Hormones influence the social behaviour of dogs. Castration of male dogs induces a reduction of testosterone and has been shown to affect social behaviours associated with aggression and reproduction. Changes in social behaviour could be critical in working dogs, which should be well trainable and behave reliably. It is currently unknown whether and how castration may affect the working ability of dogs. Besides surgical castration, chemical castration using a hormonal implant offers a possibility to castrate dogs temporarily. In the present study, we chemically castrated male Swiss military dogs and assessed their working abilities in comparison to intact males in a standard behavioural test series for Swiss military dogs (obedience, protection of the handler against an attacker, search of a hidden person in a building, reaction to social environment during a city walk). Chemical castration in Swiss military dogs had no measurable effect on any of the test situations in comparison to intact males.
... In contrast, 81.6% of dog owners in metropolitan Chicago kept their dogs primarily as indoor companions (Freiwald et al., 2014). With the trend towards keeping smaller dogs (Teng et al., 2016) and housing them indoors more often (Animal Medicines Australia, 2016), house-soiling may possibly become more obvious as a sign of separation-related distress in Australian dogs in the future. ...
Separation-related behaviours are reported in an estimated 14–29% of companion dogs. To investigate risk factors for these behaviours, owners were asked to complete a questionnaire, largely based on the Canine Behavioural Assessment and Research Questionnaire (C-BARQ), to report the behaviour of golden retrievers (n = 266) and Labrador retrievers (n = 247). Statistical analysis identified significant correlations between separation-related behaviour (SRB) scores with a group of traits including attachment and attention-seeking behaviour (rs = 0.43, P < 0.001), excitability (rs = 0.38, P < 0.001), non-social fear (rs = 0.34, P < 0.001), and touch sensitivity (rs = 0.32, P < 0.001). Logistic regression analysis identified source of acquisition, age, breed, sex and neuter status as significant predictors of the presence of SRB. SRB was more likely to be present in dogs acquired from pet shops and shelters than in those from service organisations or breeders. SRB was most likely to be seen in castrated males and least likely to be seen in intact males Future research should focus on the relative impact of risk factors we have identified here. This will facilitate early recognition of behavioural predictors, and prompt owners to seek professional help to alleviate distress in their dogs.
... When the heritability of various behaviors of German shepherd puppies bred to be working dogs was investigated, a strong linkage between genetic factors and activity was shown, with the highest heritability score being 0.53 [36]. In addition, there was a high genetic heritability score of 0.90 for aggression expressed towards strangers [33]. However, other studies have reported conflicting results, showing low heritability of activity and cognitive abilities including memory and learning in dogs [18,25]. ...
Somatic cell nuclear transfer allows us to generate genetically identical animals by using donor cells derived from animals with particular traits. So far, little research has been performed on whether or not these cloned dogs will show identical behavior patterns. To address this question, learning, memory and exploratory patterns were examined using six cloned dogs with identical nuclear genomes. The variance of total incorrect choice number in the Y-maze test among cloned dogs was significantly lower than that of the control dogs. Also, there was a significant decrease in variance in the level of exploratory activity in the open fields test compared to age-matched control dogs (P<0.05). These results indicate that cloned dogs show similar cognitive and exploratory patterns, suggesting that these behavioral phenotypes are related to the genotype of individuals.
... This turns out to be quite difficult in practice in both human and canine genetics. For instance, in our work on the genetics of canine aggressive behavior, we have used three methods for phenotyping: a behavioral test of the dog (van den Berg et al. 2003), a questionnaire for the dog owner (van den Berg et al. 2006), and a personal interview with the dog owner (van den Berg et al. 2003;. We obtained the most promising heritability estimates (i.e. ...
All modern dog breeds are descendants of the grey wolf. Dogs were originally selected for behavioral traits: dogs have been bred to guard, herd, hunt, pull sledges, and to provide companionship. Early canid domestication involved selection for tameness. Studies of silver foxes at the Institute of Cytology and Genetics in Novosibirsk have shown that a few generations of selection for tameness can lead to a domesticated strain of foxes that not only show dog-like behaviors, but that also display phenotypic traits such as curly tails, drop ears, and loss of pigment. The early domestication of dogs was followed by the formation of dog breeds much later. Extreme founder effects, drift, and selection for novelty, in combination with genetic isolation during breed formation, have resulted in a canine genome sequence with features that are highly favorable for the molecular genetic study of inherited traits. Long linkage disequilibrium within breeds and a limited number of short common haplotypes across breeds greatly facilitate gene mapping. Canine genomic tools such as microarrays for genotyping and gene expression studies have enabled the identification of causal mutations for several canine morphological and disease susceptibility traits in recent years. In this review chapter, we discuss the latest knowledge regarding the inheritance of behavioral traits in dogs. We also describe molecular genetic studies that have pinpointed some genetic variants that contribute to behavior. Behavioral traits that are discussed are canine personality, working behavior, anxiety, aggression, obsessive-compulsive disorder, and feeding behavior.
... This turns out to be quite difficult in practice in both human and canine genetics. For instance, in our work on the genetics of canine aggressive behavior, we have used three methods for phenotyping: a behavioral test of the dog (van den Berg et al. 2003), a questionnaire for the dog owner (van den Berg et al. 2006), and a personal interview with the dog owner (van den Berg et al. 2003;. We obtained the most promising heritability estimates (i.e. ...
All modern dog breeds are descendants of the grey wolf. Dogs were originally selected for behavioral traits: dogs have been bred to guard, herd, hunt, pull sledges, and to provide companionship. Early canid domestication involved selection for tameness. Studies of silver foxes at the Institute of Cytology and Genetics in Novosibirsk have shown that a few generations of selection for tameness can lead to a domesticated strain of foxes that not only show dog-like behaviors, but that also display phenotypic traits such as curly tails, drop ears, and loss of pigment. The early domestication of dogs was followed by the formation of dog breeds much later. Extreme founder effects, drift, and selection for novelty, in combination with genetic isolation during breed formation, have resulted in a canine genome sequence with features that are highly favorable for the molecular genetic study of inherited traits. Long linkage disequilibrium within breeds and a limited number of short common haplotypes across breeds greatly facilitate gene mapping. Canine genomic tools such as microarrays for genotyping and gene expression studies have enabled the identification of causal mutations for several canine morphological and disease susceptibility traits in recent years. In this review chapter, we discuss the latest knowledge regarding the inheritance of behavioral traits in dogs. We also describe molecular genetic studies that have pinpointed some genetic variants that contribute to behavior. Behavioral traits that are discussed are canine personality, working behavior, anxiety, aggression, obsessive-compulsive disorder, and feeding behavior.
... In accordance with previous studies (Mackenzie et al., 1986;Willis, 1995;Houpt and Willis, 2001;Houpt, 2007;Hall and Wynne, 2012), also the present meta-analysis has shown low general heritability of the categorised behavioural traits analysed. When compared with the previous reports, the novelty of this study lies in the fact that individual high values of heritability reported either for individual trait or traits within a study (e.g., Fält et al., 1982;Goddard and Beilharz, 1985;Kreiner et al., 1992;Schmutz and Schmutz, 1998;Wilsson and Sundgren, 1998;van den Berg et al., 2006b;Liinamo et al., 2007), or for a single dog breed (Kreiner et al., 1992;Schmutz and Schmutz, 1998) disappeared when statistical synthesis of the data across studies was applied. The occasional high values of heritability, shown for example in Figs. ...
... Two new factors (energy and dog rivalry) were added subsequently, and one of the original factors (dog-directed aggression/fear) was divided into two (dog-directed aggression and dog-directed fear) to create a total of 14 factors. This factor structure has been found to be remarkably consistent irrespective of breed, sex, or geographic location (Duffy et al. 2008;Hsu and Serpell 2003;Hsu and Sun 2010;Nagasawa et al. 2011;van den Berg et al. 2006van den Berg et al. , 2010. Twenty-two miscellaneous items are also included in the C-BARQ as stand-alone behavioral measures. ...
Domestic dogs display an extraordinary level of phenotypic diversity in morphology and behavior. Furthermore, due to breeding practices introduced during the nineteenth century, these phenotypic traits have become relatively 'fixed' within breeds, allowing biologists to obtain unique insights regarding the genetic bases of behavioral diversity, and the effects of domestication and artificial selection on temperament. Here we explore differences in behavior among the 30 most popular dog breeds registered with the American Kennel Club based on owner responses to a standardized and validated behavioral questionnaire (C-BARQ). The findings indicate that some breed-associated temperament traits (e.g. fear/anxiety) may be linked to specific gene mutations, while others may represent more general behavioral legacies of 'ancient' ancestry, physical deformity, and/or human selection for specific functional abilities. They also suggest that previous efforts to relate dog breed popularity to behavior may have failed due to the confounding effects of body size.
... Estrogen and oxytocin have anxiolytic effects, 20 which possibly accounts for the findings that spaying may worsen aggressive behavior in dogs exhibiting aggression before surgery 21 and increase some dogs' reactivity toward unfamiliar people. 22 Evidence that human-directed aggression is a heritable trait has been shown in several different breeds (golden retrievers, 23,24 English cocker spaniels, 25 English springer spaniels 26 ). Owners of aggressive dogs should be counseled to neuter or spay their pets to avoid passing on genes related to aggression. ...
This article reviews the various causes of human-directed aggression in dogs and provides a step-by-step plan guiding the general practitioner through history taking, behavior observations, diagnosis, consultation, treatment, and follow-up care. Charts summarizing how to obtain behavioral information, the client's management options, treatment recommendations, diagnosis and treatment of human-directed aggression, and the clinician's role in preventing human-directed aggression are included. A graphic illustration of canine body language is also provided.
... Differences were seen in whether the aggression was directed toward familiar people, unfamiliar people or dogs (Duffy et al. 2008). Van den Berg et al. (2006) administered the CBARQ to the owners of the cohort of dogs previously tested on the modified Netto and Planta (1997) aggression test summarized above. Van den Berg et al. (2008) noted that a factor analysis from the aggression test yielded two factors similar to the CBARQ categories: 'dog-directed aggression' and 'stranger-directed aggression'. ...
We review a range of studies on the genetic contribution to behavior in canid species. We begin by identifying factors that make canids a promising model in behavioral genetics and proceed to review research over the last decade that has used canids to identify genetic contributions to behavior. We first review studies that have selectively bred dogs to identify genetic contributions to behavior and then review studies that estimate heritability from populations of non-laboratory bred dogs. We subsequently review studies that used molecular genetics to identify gene-behavior associations and note associations that have been uncovered. We then note challenges in canid behavioral genetics research that require further consideration. We finish by suggesting alternative phenotyping methods and identify areas in which canids may have as yet unexploited advantages, such as in gene-environment interaction studies where genetic factors are found to moderate the effects of environmental variables.
... This has been demonstrated by studies that conducted behavioral tests and compared behavior between dogs aged four and 12 months [10], as well as eight weeks and 3-6 years [19]. Behavioral tests are desirable for their objectivity, but they may be less representative than questionnaire surveys and thus have a risk to miss finding out a possible consistent behavior when the test content does not match the target behavioral trait [18]. Therefore, questionnaire surveys, such as the one conducted in the present study, can be effective as preliminary survey, because they can include several possible situations at one time and may indicate how a target adult behavior will appear during the puppy period. ...
Guide dogs help visually impaired persons both physically and psychologically. More than half of all candidate dogs do not qualify, mainly for behavioral reasons. Improved training efficacy is desirable, and earlier prediction of qualification-related traits would be beneficial. In a previous study, we identified 'Distraction', assessed during the training period, as an important behavioral trait for judging the qualification of guide dogs at the Japan Guide Dog Association. As a second step, we aimed to develop an index that can predict during the puppy period. In this study, candidate guide dogs, 5-month-old Labrador retrievers, were assessed by puppy raisers using a newly developed questionnaire that consisted of 20 items. The same dogs were assessed later, at 15 months, by trainers to determine 'Distraction'. In principal components analysis, 9 items, including excitability toward strangers, initiative while out for a walk, and exploration, composed the first principal component (PC1). When we compared PC1 points with 'Distraction' points, the two categories were positively correlated (n=110, r(s)=0.31, P=0.0009). Although the accuracy of the questionnaire should be increased, the results of the present study suggest that it may be possible to assess and predict 'Distraction', which is associated with disqualification for guide dogs, early in the puppy-raising period.
... The behavioural profiles observed in this study consistently agree with the classification of cognitive status obtained by our questionnaire in the same cohort of dogs. Questionnaires that include psychometric scales have been successfully used for measuring and phenotyping behaviour in dogs (van den Berg et al., 2006). Furthermore, this questionnaire-based classification of cognitive status was related to plasma Ab levels (González-Martínez et al., 2011). ...
Changes in social interactions with owners and other dogs are frequently observed in dogs with cognitive dysfunction syndrome (CDS). The aim of this work was to assess the effect of age and severity of CDS on social responsiveness. This is the second part of a 2-part report on spontaneous activity in pet dogs. A human interaction test and a mirror test were administered at baseline and 6months later to assess social responses to humans and conspecifics, respectively, to four groups of privately-owned dogs: young (n=9), middle-aged (n=9), cognitively unimpaired aged (n=31), and cognitively impaired aged (n=36). The severity of cognitive impairment was considered in the last group and dogs were categorised as having either mild or severe CDS. The influence of the person and the mirror on locomotion and exploratory behaviour was also studied. Dogs were recorded in a testing room and the video recordings were subsequently analysed. Young dogs displayed more interactions involving physical contact with a person. Young and middle-aged dogs showed more vocalisations in response to social isolation. In contrast, aged animals spent more time in front of the mirror. Changes in social responsiveness associated with severe CDS included decreased response to social isolation and human interaction and increased time in front of the mirror, suggesting a deficit in habituation. Testing of spontaneous activity might help to characterise CDS in aged dogs, a condition increasingly diagnosed in veterinary clinics and a potentially useful natural model of Alzheimer's disease in humans.
Traditional methods of data analysis in animal behavior research are usually based on measuring behavior by manually coding a set of chosen behavioral parameters, which is naturally prone to human bias and error, and is also a tedious labor-intensive task. Machine learning techniques are increasingly applied to support researchers in this field, mostly in a supervised manner: for tracking animals, detecting land marks or recognizing actions. Unsupervised methods are increasingly used, but are under-explored in the context of behavior studies and applied contexts such as behavioral testing of dogs. This study explores the potential of unsupervised approaches such as clustering for the automated discovery of patterns in data which have potential behavioral meaning. We aim to demonstrate that such patterns can be useful at exploratory stages of data analysis before forming specific hypotheses. To this end, we propose a concrete method for grouping video trials of behavioral testing of animal individuals into clusters using a set of potentially relevant features. Using an example of protocol for testing in a “Stranger Test”, we compare the discovered clusters against the C-BARQ owner-based questionnaire, which is commonly used for dog behavioral trait assessment, showing that our method separated well between dogs with higher C-BARQ scores for stranger fear, and those with lower scores. This demonstrates potential use of such clustering approach for exploration prior to hypothesis forming and testing in behavioral research.
Through domestication and subsequent selection dogs’ morphological and behavioural traits have been selected for functional purposes beyond companionship. Since dogs are kept as pets worldwide and live in close contact with humans, gathering information on the behavioural characteristics of breeds either potentially problematic or obtained through hybridization appears particularly relevant. In the current study, the C-BARQ questionnaire was used to examine the behaviour of the Czechoslovakian wolfdog, a recent breed obtained through hybridization of the Carpathian wolf and the German shepherd dog and rapidly growing in popularity. One thousand four hundred twenty owners, 1119 from Italy and 301 from the Czech Republic completed the online questionnaire providing data on Czechoslovakian wolfdogs (CWDs), their sister breed, i.e. German shepherd dogs (GSs), and Labrador retrievers (LRs).
Overall some behavioural differences among the breeds emerged together with discrepancies between Italian and Czech owners in the evaluation of some behavioural traits.
Italian owners outlined only a few breeds and/or sex differences. Regardless of breed and training male dogs were rated as more aggressive towards other dogs, more excitable and active, more prone to show attention-seeking behaviour, less trainable, and less prone than females to engage in chasing than females. CWDs showed less stranger-directed fear than GSs and LRs and less non-social fear than GSs. According to Czech owners, males were generally more aggressive than females and CWDs and GSs were significantly more aggressive towards strangers and other dogs than LRs. CWDs showed more stranger-directed fear and separation-related behaviour and were less trainable than both GSs and LRs. The training was generally reported to reduce aggressive and separation-related behaviour, fear of strangers and non-social stimuli, and chasing tendencies. Taken together these findings suggest that CWDs could be more similar to ancient breeds (more wolf-like) for some behavioural traits and like modern breeds for others. Different breeding practices and/or social/environmental conditions such as socialization, handling, training methods but also owners’ perceptions and expectations about a given breed could explain the differences in rating that emerged between the two countries.
This study investigated whether stress responsiveness (in one context) can be used to predict dog behavior in daily life. On two occasions (NT1 = 32 puppies; NT2 = 16 young adults), dogs' physiological stress response after a behavioral test at home was measured in terms of reactivity (10 min post-test) and recovery (40 min post-test) for three salivary markers: cortisol, chromogranin A (CgA) and secretory immunoglobulin A (sIgA). For each marker, it was determined whether dogs with a strong physiological response displayed different behavior in daily life compared to dogs with a weaker physiological response. The results revealed three main findings: first, for CgA and cortisol, different patterns were identified according to sample time. High reactivity related to desirable traits, whereas slow recovery after the behavioral test related to undesirable traits. The findings suggest that increased levels of CgA and cortisol 10 minutes after the behavioral test reflected an adaptive stress response, whereas elevated levels 40 minutes after the test reflected unsuccessful coping. Second, patterns for sIgA differed from CgA and cortisol: significant associations were only found with behavioral traits at T2, mostly considered desirable and related to Trainability. Possibly, the delayed reaction pattern of sIgA caused this difference between markers, as sIgA reflects the (secondary) immune response to stress, due to immunosuppressive effects of cortisol. Third, predictive capacity of puppies' physiological stress response (T1) was inconclusive, and contrary relations were found with behavioral traits at T2, suggesting that developmental factors play an important role. This study provides new insights about the relation between stress physiology and behavioral traits, and methodological advice is given to study these patterns further. In conclusion, physiological markers could provide additional insights in dogs' tendencies to display certain behaviors, especially at the young adult stage. Further studies are needed to confirm these patterns.
The results of this pilot study demonstrate that it is possible to construct a reliable questionnaire from prior validated surveys. This questionnaire displays possible suitability for further development into a tool for a comprehensive dog welfare assessment. The welfare model used is assuming that canine welfare consists of three major considerations, the dogs’ behavior, the dogs’ quality of life (QoL dog) and the owner’s quality of life as pertaining to being a dog owner (QoL Owner). A questionnaire was constructed and tested. Three different parts from reliable and validated sections of previous surveys were included: 1) a modified C-BARQ, 2) QoL for the dog, and 3) QoL owner. 185 satisfactory answers were obtained from the respondents, dog owners in Sweden, Canada and USA. Principal component factor analysis rendered 13 extracted factors similar to the original questionnaires, suggesting that the construct is valid. Eleven of the thirteen factors showed moderate internal consistency of Cronbach’s alpha >0.7, the remaining two factors were relatively low with Cronbach’s alpha >0.6.
Several significant correlations between the extracted factors were found. Quality of life as a dog owner (QoL owner) was significantly affected by stress caused by dogs displaying fear, excitability and separation anxiety. No significant correlations were found between any factors describing aggressive behaviors and the dogs QoL or QoL owner. Several significant correlations were found between the extracted factors and the demographics, for instance, the Swedes are more active with their dogs compared to Americans and Canadians. Further investigations should be commenced to validate the results in a larger population.
The domestic dog represents one of the most dramatic long-term evolutionary experiments undertaken by humans. From a large wolf-like progenitor, unparalleled diversity in phenotype and behaviour has developed in dogs, providing a model for understanding the developmental and genomic mechanisms of diversification. We discuss pattern and process in domestication, beginning with general findings about early domestication and problems in documenting selection at the genomic level. Furthermore, we summarize genotype–phenotype studies based first on single nucleotide polymorphism (SNP) genotyping and then with whole-genome data and show how an understanding of evolution informs topics as different as human history, adaptive and deleterious variation, morphological development, ageing, cancer and behaviour.
Risk factors for human-directed aggression were investigated using retrospective analysis of data from a referral-level clinical behaviour population in the UK. A sample of 200 cases involving human-directed canine aggression and 200 control cases involving no instance of human-directed aggression were selected at random from a population of 746 cases. The final model suggested that clinical cases with human-directed aggression were significantly younger than those presenting with other undesired behaviours (P=0.008) and that male dogs were 1.4 times more likely to be aggressive towards human beings than female dogs (P=0.019). Dogs were 1.7 times more likely to be aggressive towards people if they had attended more than five puppy classes than if they had never attended puppy class (P=0.015) and that dogs were 2.8 times more likely to be aggressive towards human beings if there was another dog between 0 months and 24 months of age in the home (P=0.004). These factors only account for 7 per cent to 10 per cent of the variance between the human-directed aggression population and the control population, but factors such as attendance at puppy classes and numbers of dogs in the household suggest the need for longitudinal studies to investigate temporal relationships.
The study of dog personality is of general academic interest and also has applications for the management of both working dogs and pets. However, acquiring direct behavioral assessments of large numbers of animals is both time-consuming and logistically difficult. An alternative approach that is becoming increasingly common is the collection of questionnaire-based information directly from dog owners. In this review, we discuss some commonly used questionnaires for dog personality traits and findings that have been published using these tools. We suggest that the use of such questionnaires may contribute to research that is based on estimation of effects from large sample sizes, for example, genomic analyses of dog personality traits.
A visit to a veterinary clinic can be very stressful for the dog, and stress may interact with pain. The aim of this study was to observe the behavior of dogs in a veterinary clinic and to correlate it with subjective stress assessments by different persons. Systems have already been developed to assess pain in dogs. We tested the behavior of 105 dogs, sampled from 233 dog-owners who completed our questionnaire and whose dogs were patients at the clinic. The dog-owner, the test leader, the nurse and the veterinarian were each asked to assess if the dog was experiencing pain or was stressed and to evaluate, overall, how the dog experienced the visit. Three behavior tests were also carried out to describe the dog’s reaction in the veterinary clinic: a ‘social contact’ test, a ‘play’ test and a ‘treat’ test. The play and treat tests were carried out both inside and outside the veterinary clinic to see if the dogs reacted differently in the two situations. Agreement between observers was good to excellent, but generally better when assessing pain than stress. Dogs rated as more stressed were significantly less likely to engage in social contact with an unfamiliar person (p<0.0001). They were significantly more willing to play and eat a treat outside the veterinary clinic compared to inside the clinic (p<0.001), implying that the dogs themselves experienced inside the clinic as being more negative. The results also indicated that the type of relationship the owner has with the dog may influence the dog’s behavior during the clinical examination. The good agreements between the different measures in this study suggest that there is potential for a system to be developed to assess the extent to which the dog is stressed in the clinic.
Records of dogs presented to a behavior clinic servicing the eastern seaboard of Australia in and around Brisbane and the Gold Coast were analysed for principal behavior problems and the related factors, from information recorded at the time that the owner approached the clinic for assistance. Data relating to 7,858 dogs presenting with 11,521 behavior problems between 2001 and 2013 were analysed. Twenty-two principal behavior problems were identified, of which the most common, in declining order, were aggression towards people, barking and anxious behavior. Male dogs were at greater risk of several behavior problems, compared to female dogs. Low socioeconomic status of owners and a short period spent at home each week were also associated with a greater risk of several behavior problems. The prevalence of breeds and breed groups presented to the clinic were compared with dog registrations at the local city council, and there were more working dogs, hounds and utility dogs and fewer terriers, toy dogs and non-sporting dogs in the clinic population. Uncommon breeds were over-represented in the clinic population compared to local registrations. The risk of developing behavior problems is discussed in the light of evidence about the dogs and their owners.
Dog bites constitute an important cause of morbidity worldwide, although they are rarely fatal. In Flanders the annual incidence amounts to 0.7/1.000/y (95% CI = [0.6,0.8]) for children admitted to emergency units. A thorough evaluation of the wound remains essential. Wound management consists of irrigation, wound toilet and wound closure. The necessity of analgesia, antibiotics, tetanus vaccination and rabies profylaxis should be considered for each patient individually. In case of a wound infection, one must administer antibiotics. Besides the medical support, one should keep in mind the impact of such traumas on the psychological health of the victim. As regards the prevention of dog bites one should take into account that the tendency for a dog to bite depends on several intertweening factors, including heredity, the early experience of the dog, its socialisation, training and health. Moreover, most bite incidents occur at home and with a known dog. In young children, also the behaviour of the victim appears to be an important triggering factor. Thus the Blue Dog© prevention programme was developed. It intends to educate parents as well as young children about how to interact with their dog in a safe way.
Abstract Two studies examined human perceptions of dog personality attributes based upon exposure to pictures of dogs of select breeds. The proposed hypotheses evaluated the validity of “big, black dog syndrome”—whereby large, black dog breeds are reportedly spurned for adoption due to negatively perceived personality attributes—by assessing each dog’s relative trait dominance and affiliation based upon a taxonomy drawn from the eight-factor interpersonal circumplex. Results of two separate studies indicated that among participants’ ratings, breed-specific differences were more powerful predictors of interpersonal trait attributions than the color or size of the dog. In general, with the exception of the golden retriever, black labs were perceived as consistently less dominant and less hostile than other large breeds, contrary to the assumption that large, black dogs are viewed negatively.
Pediatric gonadectomy is most commonly performed by humane organizations as a means of population control. Benefits and detriments of gonadectomy are reviewed, with special attention to literature describing effects specific to age at gonadectomy. Techniques for pediatric anesthesia and surgery are reviewed.
This paper merges together the growing theoretical interest in nonhumans with longstanding philosophical questions about form in order to assess the political and ethical ramifications of contemporary human engagements with domestic dogs. In particular, this paper explores the organizational and legal activities of the American Kennel Club (AKC) to highlight the importance of form in their political engagements and to illustrate some of the unintended consequences these activities produce. Although the AKC attempts to instantiate its own vision of the ideal dog, the organization is incapable of solidifying the character of the domestic dog, for it must contend with other groups (animal welfare groups, dogfighters, governmental agencies, and dogs themselves) which have different visions of the ideal dog. To accentuate and counteract these failings, formlessness is utilized here as a tool and as a normative ethic to reconsider the nature of human-nonhuman relations. Dogs are an ideal subject for such an investigation because they exist in many different forms that are themselves susceptible to considerable change. Yet the specific findings described here should be applicable to a wide range of natural phenomena since the interplay between form and formlessness is generally pervasive throughout the world.
Information on the behavior of both aggressive and nonaggressive (control) English cocker spaniels (ECS) recruited for genetic analysis is presented. Information from a total of 122 dogs was gathered using questionnaires and owner interviews, resulting in analysis of 52 aggressive (5 aggressive dogs were excluded from the analysis) and 65 control dogs. Owners rated their dogs with 5-point frequency scales for unacceptable behavior toward humans (17 items), fear (20 items), barking (8 items), and aggression toward other dogs (4 items). The results show that serious, repeated growling is the most pronounced single behavior characterizing the aggressive ECS, and this seems to be the most important behavior causing owners to classify their dogs as aggressive. The other main behavior characteristic of the aggressive group was skin-penetrating bites. Snapping and “biting in general” were also frequently reported among these dogs. The objective of this study was to describe some behavioral characteristics of ECS showing owner-defined aggressive behavior, and behavioral differences between these dogs and a group of ECS with excellent behavior.
As part of a collaborative project involving five guide and service dog organizations in the USA (Canine Companions for Independence, Guide Dogs for the Blind, Guiding Eyes for the Blind, Leader Dogs for the Blind and The Seeing Eye), volunteer puppy raisers provided information about the behavior of the guide and service dogs in their care via a questionnaire (the Canine Behavioral Assessment and Research Questionnaire, or C-BARQ (c); www.cbarq.org). The surveys were completed online when the puppies were 6 months old and again at 12 months of age. Dogs were tracked through training and those that successfully completed training and were matched with a blind/disabled handler or were selected as breeders were classified as "successful" while dogs rejected from the program due to behavioral issues were classified as "released" (dogs rejected for medical reasons were excluded from analysis). A total of 11,997 C-BARQ evaluations for 7696 dogs were analyzed. Generalized linear modeling for each of the five schools revealed that dogs that successfully completed training scored more favorably on 27 out of 36 C-BARQ traits at both 6 and 12 months of age compared to those that were released from the programs. The most predictive trait at both age levels was 'pulls excessively hard on leash,' for which each unit increase in score was associated with a 1.4 increase in the odds of being released from the program. The ability of the C-BARQ to discriminate between dogs that were later successful or released differed across organizations (P = 0.001 and P < 0.0001 for 6- and 12-month surveys, respectively), most likely due to differences in the procedures used when making decisions about whether or not to release dogs. These findings provide convincing evidence that the C-BARQ is able to discriminate between dogs that are behaviorally suited for guide or service work and those that are not and may provide trainers with useful information about potential training or breeding candidates as early as 6 months of age.
In this study, heritabilities of several measures of aggression were estimated in a group of 325 Golden Retrievers, using the Restricted Maximum Likelihood method. The studied measures were obtained either through owner opinions or by using the Canine Behavioural Assessment and Research Questionnaire (CBARQ). The aim of the study was to determine which of the aggression measures showed sufficient genetic variation to be useful as phenotypes for future molecular genetic studies on aggression in this population. The most reliable heritability estimates seemed to be those for simple dog owner impressions of human- and dog-directed aggression, with heritability estimates of 0.77 (S.E. 0.09) and 0.81 (S.E. 0.09), respectively. In addition, several CBARQ-derived measures related to human-directed aggression showed clear genetic differences between the dogs. The correlation between the estimated breeding values for owner impressions on human- and dog-directed aggression was relatively low. The low correlation suggests that these two traits have a partially different genetic background. They will therefore have to be treated as separate traits in further genetic studies.
The Silences of the Archives, the Reknown of the Story.
The Martin Guerre affair has been told many times since Jean de Coras and Guillaume Lesueur published their stories in 1561. It is in many ways a perfect intrigue with uncanny resemblance, persuasive deception and a surprizing end when the two Martin stood face to face, memory to memory, before captivated judges and a guilty feeling Bertrande de Rols. The historian wanted to go beyond the known story in order to discover the world of the heroes. This research led to disappointments and surprizes as documents were discovered concerning the environment of Artigat’s inhabitants and bearing directly on the main characters thanks to notarial contracts. Along the way, study of the works of Coras and Lesueur took a new direction. Coming back to the affair a quarter century later did not result in finding new documents (some are perhaps still buried in Spanish archives), but by going back over her tracks, the historian could only be struck by the silences of the archives that refuse to reveal their secrets and, at the same time, by the possible openings they suggest, by the intuition that almost invisible threads link here and there characters and events.
Two thousand questionnaires were distributed randomly via the Kennel Club (UK) to owners of purebred English Cocker Spaniels (ECSs). Owners were asked to give details about the ECSs they owned: age, sex, neuter status, coat colour. They were also asked to indicate whether their dog showed aggression (on a 1–5 scale; 1, never or almost never; 5, always or almost always) in any of 13 situations. These were: aggression towards strange dogs (A1), towards strangers approaching the dog (A2), towards persons approaching/visiting the home (A3), towards persons approaching the owner away from home (A4), towards children in the household (A5), towards other dogs in the household (A6), when the owner gives attention to other person or animal (A7), toward owner or member of owner's family (A8), when disciplined (A9), when reached for or handled (A10), when in restricted spaces (A11), at meal times/ defending food (A12) and, suddenly and without apparent reason (A13).
Here we report a high-quality draft genome sequence of the domestic dog (Canis familiaris), together with a dense map of single nucleotide polymorphisms (SNPs) across breeds. The dog is of particular interest because it provides important evolutionary information and because existing breeds show great phenotypic diversity for morphological, physiological and behavioural traits. We use sequence comparison with the primate and rodent lineages to shed light on the structure and evolution of genomes and genes. Notably, the majority of the most highly conserved non-coding sequences in mammalian genomes are clustered near a small subset of genes with important roles in development. Analysis of SNPs reveals long-range haplotypes across the entire dog genome, and defines the nature of genetic diversity within and across breeds. The current SNP map now makes it possible for genome-wide association studies to identify genes responsible for diseases and traits, with important consequences for human and companion animal health.
Data were obtained from a total of 245 cases of aggressive-behavior problems in dogs kept as companion animals. Aggression involved barking, growling and biting behavior. For each case, a home visit of one to several hours yielded a description of the sequences of aggressive behavior and the stimulus conditions in which they occurred. Eight major types of aggression were observed: aggression related to fear; dominance; possessiveness; protectiveness; predation; punishment; pain; and intra-specific aggression.The incidence of each type of aggression is presented. More aggression problems occurred in males than females, with dominance and inter-male aggression showing the greatest likelihood of occurrence in males. Fear-elicited aggression and predatory aggression were the least influenced by the sex of the dog. Tabulation of associations among these problems revealed that dominance and possessive aggression frequently occurred together, fear-elicited and intra-specific aggression frequently occurred alone, and many of the aggression problems were associated with non-aggressive problems related to fear (phobias) and anxiety. The data indicated that aggressive-behavior problems are widespread across many breeds and suggest some breed × problem interactions. Fewer instances of dominance aggression occurred in mixed than in pure breeds. A classification system, proposed to represent the functional sub-systems of aggression in the pet dog, is presented.
Sixteen incidents involving dog bites fitting the description "severe" were identified among 5,711 dog bite incidents reported to health departments in five South Carolina counties (population 750,912 in 1980) between July 1, 1979, and June 30, 1982. A "severe" attack was defined as one in which the dog "repeatedly bit or vigorously shook its victim, and the victim or the person intervening had extreme difficulty terminating the attack." Information from health department records was clarified by interviews with animal control officers, health and police officials, and persons with firsthand knowledge of the events. Investigation disclosed that the dogs involved in the 16 severe attacks were reproductively intact males. The median age of the dogs was 3 years. A majority of the attacks were by American Staffordshire terriers, St. Bernards, and cocker spaniels. Ten of the dogs had been aggressive toward people or other dogs before the incident that was investigated. Ten of the 16 victims of severe attacks were 10 years of age or younger; the median age of all 16 victims was 8 years. Twelve of the victims either were members of the family that owned the attacking dog or had had contact with the dog before the attack. Eleven of the victims were bitten on the head, neck, or shoulders. In 88 percent of the cases, the attacks took place in the owner's yard or home, or in the adjoining yard. In 10 of the 16 incidents, members of the victims' families witnessed the attacks. The characteristics of these attacks, only one of which proved fatal, were similar in many respects to those that have been reported for other dog bite incidents that resulted in fatalities. On the basis of this study, the author estimates that a risk of 2 fatalities per 1,000 reported dog bites may exist nationwide. Suggestions made for the prevention of severe attacks focus on changing the behavior of both potential canine attackers and potential victims.
To identify factors associated with onset and continued elicitation of tail chasing in Bull Terriers and other terriers and to determine response to treatment with clomipramine hydrochloride, a serotonin-reuptake inhibitor.
Prospective study.
18 tail-chasing terriers (15 Bull Terriers, 1 Miniature Bull Terrier, 1 American Staffordshire Terrier, 1 Jack Russell Terrier).
5 dogs were evaluated for tail chasing by a veterinarian at the behavior clinic of the veterinary teaching hospital and 13 dogs were evaluated by the owner's local veterinarian, who confirmed the diagnosis and treated the dog. It was recommended that all dogs in the study be given clomipramine orally at a dosage of 1 to 2 mg/kg (0.5 to 0.9 mg/lb) of body weight, every 12 hours.
Of the 18 dogs, 15 were treated with clomipramine within the recommended dosage range, and 3 dogs required treatment at a slightly higher dosage range to control tail chasing. After 1 to 12 weeks of treatment, 9 of 12 (75%) dogs were reported to have a 75% or greater improvement (reduction) in tail chasing.
Findings of this study may aid in recognition and treatment of compulsive tail chasing. In conjunction with appropriate management changes, clomipramine administration appears to be an effective treatment for this otherwise refractory condition.
Most guide and service dog organizations would benefit from the development of accurate methods for the early evaluation of canine temperament traits. This paper describes the development and validation of a novel questionnaire method for assessing behavior and temperament in 1-year-old guide dogs. Volunteer puppy-raisers scored a total of 1097 prospective guide dogs on a series of 40 semantic differential-type, behavioral rating scales. Principle components factor analysis of these scores extracted eight stable and interpretable common factors: stranger-directed fear/aggression, non-social fear, energy level, owner-directed aggression, chasing, trainability, attachment, and dog-directed fear/aggression. Three of these eight factors exhibited moderate internal consistency (Cronbach's alpha>/=0.72), while the reliabilities of the remaining factors were relatively low (Cronbach's alpha=0.53-0.61). The eight factors were then validated against the guide dog school's own criteria for rejecting dogs for behavioral reasons. The results of this analysis confirmed the construct validity of the puppy raisers' questionnaire assessments of their dogs, and suggested that such methods can provide a useful and accurate means of predicting the suitability of dogs for guiding work. Various modifications to the original questionnaire are proposed in order to enhance its overall reliability.
Although the serotonergic system and htr1A have been studied extensively, little is known about the canine serotonin receptor 1A. We are interested in this receptor in the dog because it is likely to be involved in behavioral disorders such as anxiety. Therefore, we isolated a canine bacterial artificial chromosome (BAC) clone containing htr1A, and, with the help of this clone, the complete canine coding sequence of this gene was determined. Radiation hybrid (RH) mapping showed that htr1A is part of a conserved linkage group also including the survival of motor neuron 1 (smn1) gene. Htr1A is estimated to be located about 7.3 Mb from smn1 on cfa02. In addition, we report a possible breed-specific variant of the gene in four golden retrievers.
To develop and validate a questionnaire to assess behavior and temperament traits of pet dogs.
Cross-sectional survey of dog owners. Animals-1,851 dogs belonging to clients of a veterinary teaching hospital or members of national breed clubs and 203 dogs examined by canine behavior practitioners because of behavior problems.
Owners were asked to complete a questionnaire consisting of 152 items eliciting information on how dogs responded to specific events and situations in their usual environment. Data from completed questionnaires were subjected to factor analysis, and the resulting factors were tested for reliability and validity.
Factor analysis yielded 11 factors from 68 of the original questionnaire items that together accounted for 57% of the common variance in questionnaire item scores. Reliability was acceptable for all but 1 of these factors. Behavior problems in 200 of the 203 dogs with behavior problems could be assigned to 7 diagnostic categories that matched 7 of the factors identified during factor analysis of questionnaire responses. Dogs assigned to particular diagnostic categories had significantly higher scores for corresponding questionnaire factors than did those assigned to unrelated diagnostic categories, indicating that the factors were valid. Validity of the remaining 4 factors could not be examined because of a lack of information on dogs with behavior problems related to these factors.
Findings suggest that the resulting 68-item questionnaire is a reliable and valid method of assessing behavior and temperament traits in dogs. The questionnaire may be useful in screening dogs for behavior problems and in evaluating the clinical effects of various treatments for behavior problems.
We used molecular markers to study genetic relationships in a diverse collection of 85 domestic dog breeds. Differences among breeds accounted for approximately 30% of genetic variation. Microsatellite genotypes were used to correctly assign 99% of individual dogs to breeds. Phylogenetic analysis separated several breeds with ancient origins from the remaining breeds with modern European origins. We identified four genetic clusters, which predominantly contained breeds with similar geographic origin, morphology, or role in human activities. These results provide a genetic classification of dog breeds and will aid studies of the genetics of phenotypic breed differences.
The serotonin receptor 1B gene (htr1B) has been suggested to be implicated in mental disorders in both humans and other species. We have isolated a canine bacterial artificial chromosome (BAC) clone containing htr1B, revealed the coding and surrounding DNA sequence of canine htr1B and designed primer sets for genomic sequencing of the gene. A mutation scan in 10 dogs revealed five single nucleotide polymorphisms in the htr1B coding sequence. By random sequencing of subclones of the BAC a polymorphic microsatellite repeat was found. We found evidence for at least four extended haplotypes in six dogs of the same breed. The chromosomal localization of the gene was confirmed by fluorescence in situ hybridisation and radiation hybrid mapping. This work provides a starting point for mutation scans and association studies on dogs with behavioural problems.
To determine prevalence of owner-directed aggression and identify associated environmental and genetic factors in English Springer Spaniels.
Prevalence survey.
1,053 adult English Springer Spaniels.
A mail survey was sent to 2,400 randomly selected owners of adult American Kennel Club-registered English Springer Spaniels. Dogs with a history of aggression to family members and familiar humans were compared with dogs without such a history.
1,053 questionnaires (56.1% of the 1,877 delivered) were completed. A history of owner-directed growling or more intense aggression was reported in 510 (48.4%) dogs. Two hundred seventy-seven (26.3%) dogs had bitten a human in the past; 65.2% of bites were directed at familiar (owner or nonowner) adults and children. Variables associated with owner-directed aggression included sex of dog (male), neuter status (neutered, regardless of sex), show or bench lines, age > 4 years, aggression to unfamiliar adults and children, acquisition from a hobby breeder, less responsiveness to obedience cues, and a specific kennel and 1 popular sire from that kennel in a 4-generation pedigree.
Owner-directed aggression in adult English Springer Spaniels was associated with a number of environmental, sex-related, and inherited factors. To reduce the risk of aggression, prospective owners might seek a female, hunting-type English Springer Spaniel from an experienced breeder. However, because risk factors are broad and varied, there are limitations to the extent to which behavior can be predicted and further study is needed of the inheritance of aggression in this breed.
This research offers a blueprint for how a cross-species comparative approach can be realized empirically. In a single design, parallel procedures and instruments were used in 2 species, dogs (Canis familiaris) and humans (Homo sapiens), to test whether personality differences exist and can be judged in dogs as accurately as in humans. Personality judgments of humans and dogs were compared on 3 accuracy criteria: internal consistency, consensus, and correspondence. Results showed that, on all 3 criteria, judgments of dogs were as accurate as judgments of humans. These findings are consistent with the evolutionary continuity hypothesis and suggest an important conclusion not widely considered by either personality or animal researchers: Personality differences do exist and can be measured in animals other than humans.
Aggressive Behavior (AGG) and Rule-Breaking Behavior (RB) are two of the eight CBCL syndromes. The phenotypic correlation between AGG and RB ranges from.48 to.76, and varies depending on the rater and the sex of the child. Prevalence of AGG and RB (i.e., T > or = 67) is in the range of 6%-7% in both boys and girls. Fifty percent to 60% of the children who are deviant on AGG are also deviant on RB and vice versa. Why so many children show problem behavior in the clinical range for both syndromes is unclear. This co-occurrence could be due to genetic factors influencing both traits, to environmental factors influencing both traits, or to both. The purpose of this study is to use a genetically informative sample to estimate genetic and environmental influences on AGG and RB and to investigate the etiology of the co-occurrence of both behaviors. We do this using multiple informants to take into account underlying sources of parental agreement and disagreement in ratings of their offspring. To this end, mother and father ratings of AGG and RB were collected by using the Child Behavior Checklist in a large sample of 12-year-old twins. Parental agreement is represented by an interparent correlation in the range of .53-.76, depending on phenotype (AGG or RB) and sex of the child. Genetic influences account for 79% and 69% of the individual differences in RB and AGG behavior (defined as AGG and RB on which both parents do agree) in boys. In girls 56% and 72% of the variance in RB and AGG are accounted for by genetic factors. Shared environmental influences are significant for RB in girls only, explaining 23% of the total variance. Eighty percent of the covariance between AGG and RB, similarly assessed by both parents, can be explained by genetic influences. So, co-occurrence in AGG and RB is mainly caused by a common set of genes. Parental disagreement seems to be a combination of so-called rater bias and of parental specific views.
Molecular genetic analysis of complex traits such as aggression strongly depends on careful phenotyping of individuals. When studying canine aggression, the information provided by the owners of the dogs is often not detailed and reliable enough for this purpose. Therefore we subjected 83 golden retrievers, both aggressive and nonaggressive individuals, to a behavioral test. These tests were analyzed with help of an ethogram, resulting in a behavioral profile for each of the dogs. In this article three methods are described of converting these profiles into a measure of behavioral phenotype. The usefulness of the methods is evaluated by comparing the test results with information provided by owners. Moreover, the hypothesis underlying all these methods, that a lowered threshold for aggressive behavior in general is present in the dogs, is also evaluated. Future research will need to reveal whether the methods meet the high standards that are necessary for studying complex traits.
It has been argued recently that adequate representation of the multilevel processes of interest in many educational settings will often require models with coefficients that are random rather than nonrandom. Computer simulation results presented here demonstrate the extent to which the two most common multilevel or contextual analysis procedures may mislead when data are, in fact, generated with a random coefficients process. In contrast, correct results are obtained with a third method, which has been recently proposed but not used yet in substantive research.
Six specific personality traits – playfulness, chase-proneness, curiosity/fearlessness, sociability, aggressiveness, and distance-playfulness – and a broad boldness dimension have been suggested for dogs in previous studies based on data collected in a standardized behavioural test (''dog mentality assessment'', DMA). In the present study I investigated the validity of the specific traits for predicting typical behaviour in everyday life. A questionnaire with items describing the dog's typical behaviour in a range of situations was sent to owners of dogs that had carried out the DMA behavioural test 1–2 years earlier. Of the questionnaires that were sent out 697 were returned, corresponding to a response rate of 73.3%. Based on factor analyses on the questionnaire data, behavioural factors in everyday life were suggested to correspond to the specific personality traits from the DMA. Correlation analyses suggested construct validity for the traits playfulness, curiosity/ fearlessness, sociability, and distance-playfulness. Chase-proneness, which I expected to be related to predatory behaviour in everyday life, was instead related to human-directed play interest and non-social fear. Aggressiveness was the only trait from the DMA with low association to all of the behavioural factors from the questionnaire. The results suggest that three components of dog personality are measured in the DMA: (1) interest in playing with humans; (2) attitude towards strangers (interest in, fear of, and aggression towards); and (3) non-social fearfulness. These three components correspond to the traits playfulness, sociability, and curiosity/fearlessness, respectively, all of which were found to be related to a higher-order shyness–boldness dimension.
A simple procedure for multiple tests of significance based on individual p-values is derived. This simple procedure is sharper than Holm's (1979) sequentially rejective procedure. Both procedures contrast the ordered p- values with the same set of critical values. Holm's procedure rejects an hypothesis only if its p-value and each of the smaller p-values are less than their corresponding critical-values. The new procedure rejects all hypotheses with smaller or equal p-values to that of any one found less than its critical value.
The aim of the study was to characterize dogs in which fear-motivated aggression was diagnosed, to describe the therapy used, and to evaluate the effectiveness of this therapy using a retrospective descriptive study. During the research period 284 dogs were referred for problem behaviour. Pear-motivated aggression was diagnosed in 73 (26%) dogs: intact males (35), castrated males (15), intact females (11) and castrated females (12). The mean age of the animals was 3.4 years ± 2.2 (SD). Mixed-breed dogs were most frequent, followed by Golden Retn"evers, Rottweilers and Bernese Mountain Dogs. The majority of the dogs expressed growling, snapping, biting, ears down, tail down and low posture. The aggression occurred mainly inside the house, towards adults or children, and especially when the dog was approached and/or touched. Diagnosis was based on data about the behavioural expressions of the animals, and about owner-dog interactions, obtained from both the owner and our own observation. Treatment consisted of 1) avoiding eliciting stimull, 2) optimizing owner-dog communication, 3) adaptation of the owner's punishing threats to the dog's response to punishment, and 4) for a certain period fitting the dog with a choker chain connected to a leash during the day. The behaviour of the dogs improved (55; 75%), remained unchanged (13; 18%), or deteriorated (5; 7%). In conclusion: fear-motivated aggression in dogs is likely to be more frequent than generally is assumed. Growling or biting in a low posture towards both adults and children, especially when the animals were approached or touched inside the house, were the main characteristics on which the diagnosis fear-motivated aggression was based. Therapy, mainly based on optimizing communication between owner and dog, proved significantly effective.
Case histories and the epidemiology of 11 fatal attacks by dogs which occurred in the United States during 1974-75 are presented. Nine children under 7 years, a 75-year-old woman, and a 17-year-old girl were the victims. The head and neck were the target areas for the attacking canids in most of the cases. A dachshund and a Basenji were the attackers in two cases; larger breeds were involved in the others. Most of the dogs were either owned by the victim's family or were neighbors' dogs known to the victims. The animals in nine cases were tested and found to be negative for rabies. Rabies was probably not indicated as provoking the attack in the other two. While the stimuli for all the fatal attacks were not clear, it appears that behavior threatening to the dogs may have occurred. If unsupervised contact between dogs, particularly large ones, and small children or physically limited adults had been avoided, these tragedies might have been prevented. No specific national surveillance is maintained on dog bites; news releases, personal communications with health and police officials, and newspaper reports were the source of data on these cases. Improved surveillance is needed to define the number of such deaths that occur and to elucidate the epidemiology of fatal attacks.
Aggression directed toward owners is a common complaint, and one that causes a great deal of emotional conflict. Assessment and treatment of this disturbing behavior problem must address owner safety as well as realistic expectations for improvement. Relatively mild aggression may be treated with a combination of prevention of injury, increased structure in the home, and safe control of the dog, including obedience training to reward the dog for deference to the owner. Disproportionately severe or unpredictable aggression is less likely to respond to treatment. Mounting evidence exists that aggressiveness is genetically and neurobiologically driven. Research in other species, and early research in the dog, suggest that aggression may be reduced by drug therapy to modify brain neurochemistry. Such treatment is not a cure, however, and should be paired with a lifelong, systematic program of safety and control in the home.
1. The classic animal models for human psychiatric conditions involves rodents. As prey species, their normal behaviors of avoidance would be considered pathological in humans and dogs. Hence, such models may not be homologous for similar behaviors found in psychiatric pathology in humans. 2. Dogs exhibit pathological behavioral conditions that may be equivalent to certain human psychiatric conditions. These canine conditions appear spontaneously or endogenously in the absence of genetic or neurochemcial manipulation, and as such, may be homologous to the human condition. 3. If canine conditions approach homology with human conditions they should have excellent face, predictive, and construct validity. 4. The canine conditions of separation anxiety, obsessive-compulsive disorder, cognitive dysfunction, dominance aggression, and panic disorder have good to excellent validity at all explored levels for human generalized anxiety disorder, obsessive-compulsive disorder, Alzheimer's disease, impulse control disorders, and panic disorder. 5. Natural canine models can aid our understanding of human psychiatric conditions.
Canine aggression directed to human beings is a common presenting complaint and requires attention to safety issues and behavior modification to minimize the risks of future aggression. Dogs may bite familiar people, including family members, or unfamiliar people for a variety of reasons. Anxiety plays an important role in aggression regardless of its target or circumstances. Effective management of aggression may include education and safety counseling for owners, lifestyle changes for dogs and owners, avoidance of provocations when possible, and behavior modification to minimize the risk of future bites. Drug therapy may be indicated to facilitate behavior modification or to reduce reactivity in the dog.
Aggressive behavior is the most frequently encountered behavioral problem in dogs. Abnormalities in brain serotonin metabolism have been described in aggressive dogs. We studied canine serotonergic genes to investigate genetic factors underlying canine aggression. Here, we describe the characterization of three genes of the canine serotonergic system: the serotonin receptor 1A and 2A gene (htr1A and htr2A) and the serotonin transporter gene (slc6A4). We isolated canine bacterial artificial chromosome clones containing these genes and designed oligonucleotides for genomic sequencing of coding regions and intron-exon boundaries. Golden retrievers were analyzed for DNA sequence variations. We found two nonsynonymous single nucleotide polymorphisms (SNPs) in the coding sequence of htr1A; one SNP close to a splice site in htr2A; and two SNPs in slc6A4, one in the coding sequence and one close to a splice site. In addition, we identified a polymorphic microsatellite marker for each gene. Htr1A is a strong candidate for involvement in the domestication of the dog. We genotyped the htr1A SNPs in 41 dogs of seven breeds with diverse behavioral characteristics. At least three SNP haplotypes were found. Our results do not support involvement of the gene in domestication.
Owners rated their companion dogs (Canis faamiliarus) on the frequency of occurrence of 127 descriptions of behavior. We conducted an exploratory principal components analysis of these behaviors for 2,018 participants that produced 22 interpretable factors (or traits). Four related to aggression indicate that aggression is not a unitary concept. Three factors relate to play and 3 describe vocal behavior. Regression analyses examined the relation of sex and obedience training (OT) to factor scores. Some unexpected relations between OT and factor scores were identified. Frequency distributions for factor scores were positively skewed for undesirable traits and negatively skewed for more desirable traits. Some common beliefs about companion dog behavior problems, such as the relation between playing tug-of-war games and aggression, are challenged. The identified factors provide some insight into the structure of temperament in companion dogs and represent traits that can be measured for individual dogs, although further refinement is needed.
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