Article

Heritability of dominant–aggressive behaviour in English Cocker Spaniels

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Abstract

A total of 51 seven-week-old English Cocker Spaniel puppies were measured for dominant–aggressive behaviour using the Campbell Test. The dogs consisted of a F1 full sibs and half sibs from matings of 4 sires with 10 dams. The purpose of this study was to determine if the variability observed in this behavioural characteristic has an additive genetic component and if so, to estimate heritability (h2). Coat colour and sex were examined as fixed effects.According to the results of the study: (1) there are highly significant differences between sexes; with males being more dominant than females, regardless of coat colour; (2) there are highly significant differences in aggressive behaviour depending on coat colour with greater to lesser dominance found in golden, black and particolour coats in that order; (3) there is no interaction between sex and colour when exhibiting greater or lesser dominance; (4) heritability, estimated on sire components, is hS2=0.20, indicating that the variability observed in dominant–aggressive behaviour is in part due to genetic factors; and (5) heritability estimated on dam components is hD2=0.46, which implies that the maternal effect (genetic and environmental) is an important factor in this type of behaviour.It is concluded that there is an additive genetic, and therefore, hereditary factor for dominant–aggressive behaviour in the English Cocker Spaniel. Some of the fixed factors include: sex (males are dominant over females), coat colour (golden-coated are the more dominant dogs followed by the black-coated and finally by the particolour coat dogs) and the common environmental effect due to litter.

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... However, dogs' cortisol levels vary across individuals during their time in the shelter [28]. Despite evidence that pigmentation can be predictive of dogs' behavior [29][30][31][32][33][34], no study to our knowledge has investigated whether dogs' pigmentation correlates with cortisol levels, particularly those living in animal shelters. ...
... Furthermore, because stress can impact a dog's behavior [37], it is possible that differential sensitivity to stress can underlie the behavioral differences observed in differently pigmented dogs. Indeed, previous research has found correlations between dogs' behavior and their pigmentation supporting the plausibility of this hypothesis [29][30][31][32][33][34]. Thus, when we consider the range of morphological and behavioral variability that shelter dogs display, these animals are a useful population to explore questions about morphology, physiology, and behavior in present-day domestic dogs. ...
... In contrast to the domestication syndrome hypothesis, several studies (all using modern purebred dogs as subjects) have reported that reduced pigmentation is associated with undesirable behavioral traits. In English cocker spaniels, Korean jindos, and Labrador retrievers, the recessive red mutation has been shown to be associated with increased aggression (spaniels and retrievers; [29][30][31][32]) and fearfulness (jindos; [33]). In Labrador retrievers, the recessive eumelanin-lightening liver mutation was associated with lower trainability [32,34]. ...
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Simple Summary Domestic dogs have a wide variety of colorations, and previous research has found that, in certain breeds, coat color can be linked to behavior. However, it is unknown if coloration is connected to dogs’ stress responses. To explore this question, we studied dogs living under stressful conditions: an animal shelter. We analyzed their urinary levels of cortisol, a stress hormone, to explore whether values from the shelter and on outings with people correlated with their coloration, specifically, their coat color/pattern, nose color, and extent of white spotting. In this preliminary study, we did not find a connection between their cortisol levels and coloration. While more research is needed, these initial findings do not suggest that dogs differ in their stress responses as a result of coloration alone. Abstract Previous research has found connections between pigmentation, behavior, and the physiological stress response in both wild and domestic animals; however, to date, no extensive research has been devoted to answering these questions in domestic dogs. Modern dogs are exposed to a variety of stressors; one well-studied stressor is residing in an animal shelter. To explore the possible relationships between dogs’ responses to stress and their pigmentation, we conducted statistical analyses of the cortisol:creatinine ratios of 208 American shelter dogs as a function of their coat color/pattern, eumelanin pigmentation, or white spotting. These dogs had been enrolled in previous welfare studies investigating the effect of interventions during which they left the animal shelter and spent time with humans. In the current investigation, we visually phenotype dogs based on photographs in order to classify their pigmentation and then conduct post hoc analyses to examine whether they differentially experience stress as a function of pigmentation. We found that the dogs did not differ significantly in their urinary cortisol:creatinine ratios based on coat color/pattern, eumelanin pigmentation, or white spotting, either while they were residing in the animal shelter or during the human interaction intervention. These preliminary data suggest that pigmentation alone does not predict the stress responses of shelter dogs; however, due to the small sample size and retrospective nature of the study, more research is needed.
... Further, ECS are over-represented in studies evaluating canine aggression [16,17], and the prevalence of aggression has been generally reported as higher in males than in females [16,[18][19][20]. It has also been reported that solidcoloured ECS are more likely to show signs of aggression than bi-coloured or tri-coloured, and that golden and red-coated ECS are more likely to show aggression than black-coated [20][21][22][23]. However, the majority of studies reporting aggression in ECS were published over 15 years ago [16,17,[19][20][21] and were based on study populations attending referral animal behavioural clinics [16,19,20], which limits the generalisability of the results to the current general ECS population. ...
... Using veterinary clinical data from the VetCompass ™ Programme [29], this study aimed to characterise the demography, common disorders, and longevity of the general population of ECS under primary veterinary care in the UK during 2016. Based on prior evidence, this study hypothesised that the prevalence of aggression is higher in males than in females [16,[18][19][20] and that the prevalence varies with coat colour with a higher prevalence in solid-coloured dogs [21,22]. The results from the current study could provide a reliable framework to assist reforms in breeding practices and ultimately contribute to improved health and welfare of ECS. ...
... In addition, a significantly higher prevalence of aggression in solidcoloured ECS was found, with the highest prevalence in golden-coloured dogs (12.1%). Previous research has reported that solid-coloured ECS are more likely to show signs of aggression than bi-coloured or tri-coloured, and that golden and red-coated are more likely to show aggression than black-coated [20][21][22][23]. The background to this association is not fully known, although a 20% heritability of dominant behaviour within the breed has been reported [22]. ...
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Plain English summary The English Cocker Spaniel (ECS) is a popular family dog in the UK, but there is limited information regarding common disorders affecting the breed. The goal of this study was to describe demography (age, sex, neuter, and bodyweight), disease occurrence, lifespan, and reasons for death in ECS by using data from the VetCompass™ Programme. The VetCompass™ Programme collects information from anonymised clinical records of dogs attending first-opinion veterinary practices in the UK. This study hypothesised that aggression is more common in males than in females, and in solid-coloured than in bi-coloured ECS dogs. English Cocker Spaniels comprised 10,313/336,865 (3.06%) of dogs under primary veterinary care during 2016. Breed popularity did not vary much from 2005 to 2016, comprising around 3% of all dogs born each year. The average age of dogs in 2016 was 4.57 years and the average adult bodyweight was 15.05 kg. The most common disorders were periodontal disease (infection of the tissues that hold the teeth in place, affecting 20.97% of the dogs), inflammation of the external ear canal (10.09%), obesity (9.88%), anal sac impaction (8.07%), diarrhoea (4.87%), and aggression (4.01%). Aggression was more common in males (4.95%) than in females (2.87%) and in solid-coloured (7.00%) than in bi-coloured (3.66%) dogs. The frequency of aggression also varied across the four most common solid colours (black, liver, golden, red), with golden-coloured dogs showing the most aggression (12.08%). The average lifespan was 11.44 years and the most common cause of death was tumours. This study shows that first-opinion clinical records can help us to understand and enhance breed health. The results can guide veterinarians in giving breed-adapted information to owners of ECS and help breeders to optimise breeding decisions. Further, this information can be used by future ECS owners to make more informed decisions when acquiring a dog if avoidance of aggression is a key priority. Periodontal disease was the most common condition affecting the breed, which highlights the importance of regular veterinary dental checks and as well as tooth brushing in ECS.
... Estimations of the heritability (h 2 ) of horse behaviour traits are rare, but association analysis between genes and personality traits (Momozawa et al., 2005) and comparative studies (Wade et al., 2009;Schröder et al., 2011) are more common. Genetic characterization of abnormal behaviour has been studied in dogs (Liinamo et al., 2007;Pérez-Guisado et al., 2006;Dodman et al., 2010), and evidence for a genetic component in stereotypies mainly comes from small mammals, such as striped mice (Jones et al., 2008). In mice, chronic stress early in the animal's development is associated with the predisposition to stereotypy (Cabib and Bonaventura, 1997;Weaver et al., 2004), and this sensitivity is suggested to be genotype dependent (Cabib et al., 1985;McBride and Hemmings, 2005) or due to epigenetic programming (Weaver et al., 2004). ...
... Calculating heritability on the underlying scale provides a more reliable basis for predicting or explaining responses to selection for a trait, where the predisposing causes of the condition may vary in different environments (McGuirk, 1989).The heritability of behavioural traits in animals varies widely. For example, h 2 was found to be 0.16-0.20 for tameness in the blue fox (Kenttämies and Smeds, 2003), and 0.2-0.81 for aggressive behaviour in dogs (Pérez-Guisado et al., 2006;Liinamo et al., 2007). ...
... The frequency of observations is known to interfere with the estimation of h 2 (Gianola, 1982). Consequently, the estimate of h 2 is rather an indicative than a true value, similar to a study on aggression related traits in Golden Retrievers (Liinamo et al., 2007) and Cocker Spaniels (Pérez-Guisado et al., 2006). This study represents a preliminary stage in genetic research of crib-biting. ...
Article
Crib-biting in horses is a stereotypical oral behaviour with a prevalence of 2.8–15%, varying between breeds. A genetic basis for crib-biting has been suggested by many researchers, but due to incomplete information on families or the lack of a sufficient number of verified crib-biters, heritability has not been determined for any horse population. However, the involvement of inheritance in behavioural traits has only been indicated by a few studies in horses, and evidence for a genetic component in stereotypies mainly comes from studies on other species.
... Estimations of the heritability (h 2 ) of horse behaviour traits are rare, but association analysis between genes and personality traits (Momozawa et al., 2005) and comparative studies (Wade et al., 2009;Schröder et al., 2011) are more common. Genetic characterization of abnormal behaviour has been studied in dogs (Liinamo et al., 2007;Pérez-Guisado et al., 2006;Dodman et al., 2010), and evidence for a genetic component in stereotypies mainly comes from small mammals, such as striped mice (Jones et al., 2008). In mice, chronic stress early in the animal's development is associated with the predisposition to stereotypy (Cabib and Bonaventura, 1997;Weaver et al., 2004), and this sensitivity is suggested to be genotype dependent (Cabib et al., 1985;McBride and Hemmings, 2005) or due to epigenetic programming (Weaver et al., 2004). ...
... Calculating heritability on the underlying scale provides a more reliable basis for predicting or explaining responses to selection for a trait, where the predisposing causes of the condition may vary in different environments (McGuirk, 1989).The heritability of behavioural traits in animals varies widely. For example, h 2 was found to be 0.16-0.20 for tameness in the blue fox (Kenttämies and Smeds, 2003), and 0.2-0.81 for aggressive behaviour in dogs (Pérez-Guisado et al., 2006;Liinamo et al., 2007). ...
... The frequency of observations is known to interfere with the estimation of h 2 (Gianola, 1982). Consequently, the estimate of h 2 is rather an indicative than a true value, similar to a study on aggression related traits in Golden Retrievers (Liinamo et al., 2007) and Cocker Spaniels (Pérez-Guisado et al., 2006). This study represents a preliminary stage in genetic research of crib-biting. ...
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Crib-biting in horses is a stereotypic oral behaviour. Genetic susceptibility has been suggested on a causal basis, together with environmental factors such as stress, gastric discomfort and frustration caused by stall restrictions. This study aimed to test the associations of known or suspected stereotypic genes with equine crib-biting, including Ghrelin, Ghrelin receptor, Leptin, Dopamine receptor, μ-opioid receptor, N-cadherin, Serotonin receptor and Semaphorin. We conducted a candidate gene study with a case-control design, including 98 crib-biting and 135 control horses of two breeds, Finnhorses and half-breds. Detailed phenotypic information on crib-biting behaviour was surveyed through an owner-completed questionnaire. Control horses were more than 10 years old and without a history of crib-biting. Single nucleotide polymorphisms flanking the candidate genes were genotyped using either Sanger sequencing or Taqman assays. According to the survey, the affected horses started crib-biting at a young age, had exhibited crib-biting for more than a year, and expressed the behaviour after feeding or when stressed. Comparison of allele frequencies between the cases and controls for each breed separately did not provide evidence of an association at any of the tested loci. These results suggest that the previously known stereotypic genes are not major risk factors for crib-biting in horses, and further genome-wide studies are warranted on larger sample cohorts.
... Bartolomé et al. [49], found differences in the CDE population structure due to coat color, with gray horses presenting a slight genetic differentiation from other coat colors. Furthermore, different authors [14][15][16] have also reported differences in coat colors related to personality traits such as calmness, boldness, or nervousness which, to some extent, are related with the way the animal perceives threat stimuli and reacts by showing stress [16,[50][51][52][53]. Conversely, some studies developed in humans found a lower pain threshold in red-haired people. ...
... As regards sex-coat color interaction, chestnut and bay female horses showed the highest ETR differences, with male horses having the same coat colors. These results were in line with previous studies which linked bay coat colors with more nervous characters, not only in horses [14], but also in foxes [58], rats [59], or dogs [50] more reactive animals [15]. Otherwise, another study [14] discovered no correlation between the chestnut genotype and the behavior test they performed, while [18] found no differences in behavior patterns between chestnut and bay horses. ...
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Horses have been valued for their diversity of coat color since prehistoric times. In particular, the pleiotropic effect that coat color genes have on behavior determines the way the horse perceives and reacts to its environment. The primary aim of this study was to evaluate the influence of coat color on basal reactivity assessed with infrared thermography as eye temperature at rest (ETR), determine their relation with the results obtained by these horses in Show Jumping competitions and to estimate the genetic parameters for this variable to test its suitability for genetic selection. A General Linear Model (GLM) and Duncan post-hoc analysis indicated differences in ETR due to coat color, sex, age, location, and breed-group factors. A Spearman’s rank correlation of 0.11 (p < 0.05) was found with ranking, indicating that less reactive horses were more likely to achieve better rankings. Heritability values ranged from 0.17 to 0.22 and were computed with a model with genetic groups and a model with residual variance heterogeneity. Breeding values were higher with the last genetic model, thus demonstrating the pleiotropic effect of coat color. These results indicate that ETR has a suitable genetic basis to be used in the breeding program to select for basal reactivity due to coat color.
... A wealth of information can be found in the scientific literature on the pleiotropic effects of the genes responsible for phaneroptical characters such as coat and eye color on the development and function of neural structures [73][74][75]. In this context, temperament features such as calmness and nervousness were reported to be quantitatively differentiated on the basis of coat color among individuals of the same species [76][77][78][79] and thus further drive the selection criteria for breeding purposes. ...
... It is important to highlight the common perception of camel herders that animals with a variable proportion of white fur (piebaldness) are the least aggressive but also the most fearful and submissive [89], which impairs their individual ability to lead collective actions. The same conclusion has been reached in dogs [78,90] and foxes [91] in domestic settings. ...
Article
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Several idiosyncratic and genetically correlated traits are known to extensively influence leadership in both domestic and wild species. For minor livestock such as camels, however, this type of behavior remains loosely defined and approached only for sex-mixed herds. The interest in knowing those animal-dependent variables that make an individual more likely to emerge as a leader in a single-sex camel herd has its basis in the sex-separated breeding of Canarian dromedary camels for utilitarian purposes. By means of an ordinal logistic regression, it was found that younger, gelded animals may perform better when eliciting the joining of mates, assuming that they were castrated just before reaching sexual maturity and once they were initiated in the pertinent domestication protocol for their lifetime functionality. The higher the body weight, the significantly (p < 0.05) higher the score in the hierarchical rank when leading group movements, although this relationship appeared to be inverse for the other considered zoometric indexes. Camels with darker and substantially depigmented coats were also significantly (p < 0.05) found to be the main initiators. Routine intraherd management and leisure tourism will be thus improved in efficiency and security through the identification and selection of the best leader camels.
... L'étude de l'héritabilité des comportements d'agression donne des résultats mitigés selon les races et les expérimentations. Alors que cette héritabilité est évaluée à près de 0,77 chez les Golden retrievers (Liinamo et al., 2007), elle l'est à 0,46 chez les cockers (Pérez-Guisado et al., 2006). L'héritabilité d'agressivité augmentée envers les humains est en revanche systématiquement différente de celle envers les autres chiens. ...
... Enfin, Il semble que certaines races possèdent des déterminismes génétiques du comportement qui leur sont propres. Par exemple, l'agressivité des cockers est significativement reliée à leur couleur (roux > noirs > particolores (blanc & feu)) (Pérez- Guisado et al., 2006). Ceci montre un lien entre phénotype et comportement spécifique à cette race. ...
Experiment Findings
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DANGEREOUS DOGS ; AGGRESSIVENESS ; LEGISLATION ; PUBLIC HEALTH ; BEHAVIOR ; DOGBITE ; RISK MANANAGMENT Risk assesment. Identification of danger. Emission X exposition = Probability of Risk. Risk consequences. Behavioural Evaluation. Behavioural Medicine. Dogs. French Law. Law Proposal. Law of 06/01/1999 and Law of 2007 and Law of 2008.
... Likewise, the effect of sex on dog performance was also described in Maremmano Hound, English Setter, Finnish Spitzs, Swedish Flatcoated Retrievers, Hovawart dog and Korean native Jindo dog (Karjalainen et al. 1996;Lindberg et al. 2004;Boenigk et al. 2006;Kim et al. 2010;Arvelius and Klemetsdal 2013;Riganelli et al. 2016). Significant effect of sex was also found in other type of competitions as in herding behaviour and defence ability observed in Border Collie, Belgian Shepherd, German Sheperd and Labrador Retrievers (Ruefenacht et al. 2002;Courreau and Langlois 2005;Van der Waaij et al. 2008;) and the aggressive behaviour in English Cocker Spaniels (Podberscek and Serpell 1996;P erez-Guisado et al. 2006). Conversely, despite our results, sex was not statistically significant on any of the studied measures in Finnish Hound (Liinamo et al. 1997). ...
... Likewise, studies related to the dog's aggressiveness in the English Cocker Spaniel showed that solid colour dogs and red/goldens were significantly more likely to show aggression than particolours and blacks. (Podberscek and Serpell 1996;P erez-Guisado et al. 2006). Furthermore, it may be assumed that, being crucial the colour pattern in predator-prey interaction, a fawn coat allows a better camouflage of the dog which lead to a better hunting performance. ...
Article
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The aim of this work was to estimate the effects of eight non-genetic factors (sex, type of coat, pigmentation, type of the trial, the number of the judges in the jury, the location where the competition took place, the subjectivity of the judge and the breeders) on the assessment of seven hunting traits (morphology, the breed style, search, approach, find, pursuit and voice) for the short-haired and rough-haired Italian Hound. The data consisted of 3172 field trial records between the years 2016 and 2017. The Mann–Whitney test and Kruskal–Wallis test showed that each factor was statistically significant for some traits: the sex of the dogs was statistically significant only for the evaluation of the morphology the type of coat for breed style, search, approach, find and voice; the pigmentation for all traits excluding approach; the number of judges for morphology, approach and find; the type of trial for all traits excluding voice. Spearman’s ρ (rho) correlation showed that high phenotypic correlations were between morphology, breed style and search. These traits showed low to moderate correlations with the other traits except breed style and search vs. pursuit. Furthermore, principal component analysis for the factor judge, location and breeders showed that among the seven traits assessed during the trials, the morphology and the breed style had the highest loading on the final score. Our results suggest that the effect of all the non-genetic factors analysed must be taken into account by the judges during the evaluation of the dogs.Highlights We evaluated the effects of eight non-genetic factors on the assessment of seven hunting traits for the Italian Hound. All the non-genetic factors had influence on some of the hunting traits considered. Principal component analysis showed that the highest loading for morphology and breed style are on location, judge and breeder. High phenotypic correlations were between morphology, breed style, search and pursuit.
... For example, alterations of the stress response are noted in colorphase foxes (Keeler et al. 1968;Keeler et al. 1970;Kukekova et al. 2012) and agouti-variant deer mice (Harris et al. 2001). Aggressiveness is associated with red coat color versus black Cocker Spaniel dogs (Pérez-Guisado et al. 2006). Additionally, a fear reaction specific to Icelandic horses with the silver coat color was recently described (Brunberg et al. 2013). ...
... This is reflected in foxes, where recessive alleles at ASIP correlated to smaller adrenal size and thus less stress response-related hormone (adrenaline or epinephrine) production (Keeler et al. 1968). Similar effects were described in deer mice and rats (Harris et al. 2001), and analogous results were obtained in the English Cocker Spaniel dog (Podberscek and Serpell 1997;Pérez-Guisado et al. 2006). In a loss-of-function mutation at ASIP, α-MSH binds to melanocortin receptors which inhibit stress-induced glucocorticoid release, decreasing the stress response (Harris et al. 2001). ...
Article
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Shared signaling pathways utilized by melanocytes and neurons result in pleiotropic traits of coat color and behavior in many mammalian species. For example, in humans polymorphisms at MC1R cause red hair, increased heat sensitivity, and lower pain tolerance. In deer mice, rats, and foxes, ASIP polymorphisms causing black coat color lead to more docile demeanors and reduced activity. Horse (Equus caballus) base coat color is primarily determined by polymorphisms at the Melanocortin-1 Receptor (MC1R) and Agouti Signaling Protein (ASIP) loci, creating a black, bay, or chestnut coat. Our goal was to investigate correlations between genetic loci for coat color and temperament traits in the horse. We genotyped a total of 215 North American Tennessee Walking Horses for the 2 most common alleles at the MC1R (E/e) and ASIP (A/a) loci using previously published PCR and RFLP methods. The horses had a mean age of 10.5 years and comprised 83 geldings, 25 stallions, and 107 mares. To assess behavior, we adapted a previously published survey for handlers to score horses from 1 to 9 on 20 questions related to specific aspects of temperament. We utilized principle component analysis to combine the individual survey scores into 4 factors of variation in temperament phenotype. A factor component detailing self-reliance correlated with genotypes at the ASIP locus; black mares (aa) were more independent than bay mares (A_) (P = 0.0063). These findings illuminate a promising and novel animal model for future study of neuroendocrine mechanisms in complex behavioral phenotypes.
... Pérez-Guisado et al [70] investigated the heritability (the percent variability due to genetics) of aggression in English Cocker Spaniels. They found that in addition to sex and coat color, nurture also influenced whether or not a dog was aggressive. ...
... They found that in addition to sex and coat color, nurture also influenced whether or not a dog was aggressive. The variance due to the sire heritability of aggression was only 0.2 (20%) whereas that due to the dam was 0.46 (46%) indicating a maternal-environmental effect [70] . ...
... In this context, horses with a gray coat color of the breed Caballo de Deporte Español (CDE) presented lower infrared temperature values at rest, measured with infrared thermography, compared to chestnut, bay or black-coated CDE horses [3]. Other authors [1,4,49] have also reported differences in coat colors related to personality traits such as calmness, boldness or nervousness which, to some extent, are related with the way the animal perceives threat stimuli and reacts by showing stress [4,[50][51][52][53]. Therefore, the position and the number of whorls on the head in PRE horses could be used as a possible predictor of temperament from an early age, and top-of-the-head hair whorls could be used as an indicator trait for use in selection against flighty temperaments [5]. ...
Article
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Simple Summary Hair whorls in horses are a hereditary trait that may be associated with various factors, including the temperament or the coat color of the animals. Hair whorls are described as changes in the hair pattern and may take various forms: circular whorls (spirals of hair with a round epicenter) and linear whorls (a line where the hairs span out on both sides from the center, producing an oval shape similar to a feather). The aim of this study is to estimate the frequency and genetic parameters of the number and position of circular and linear hair whorls (on head, body-neck and limbs) of the Pura Raza Española horse according to different factors such as gender, level of inbreeding, birth period and coat color. In this breed, circular whorls are more prevalent than linear whorls, with both showing a relevant symmetry. The laterality of hair whorls has been also evidenced and are most concentrated on the left-hand side. Most horses, particularly gray ones, showed circular hair whorls below the central line of the eyes; in a previous paper, this was associated with a calmer and more docile temperament. Hair whorls have medium-high heritability and can be included in a breeding program due to their relationship with behavior. Abstract Hair whorls are a hereditary feature in horses that may be associated with temperament and coat color. Hair whorls are described as changes in the hair pattern and may take various forms, such as circular and linear whorls. We first carried out a frequency analysis of hair whorls (circular and linear). Next, a Generalized Non-Linear Model was computed to assess the significance of some potential influencing factors, and a genetic parameter estimation was performed. ENDOG software v4.8 was used to estimate the inbreeding coefficient of all the animals analyzed. It was more common to find horses with circular hair whorls than with linear whorls. The heritability ranges obtained were, in general, medium-high for both circular whorls (0.20 to 0.90) and linear whorls (0.44 to 0.84). High positive correlations were found on the between left and right positions, indicating a tendency to symmetry in certain locations. The laterality of hair whorls was also evidenced, with the biggest concentration on the left-hand side, particularly in gray horses, showing circular whorls below the central line of eyes, which has been associated in a previous paper with a calmer and more docile temperament.
... For example, previous studies underlined a male advantage in flexibly using spatial information (Fugazza et al. 2016;Mongillo et al. 2017a;Scandurra et al. 2018c), which is an important requisite for male dogs since they range over significantly larger areas than females when free-roaming (Sparkes et al. 2014). Concerning the social sphere, male dogs show generally a higher degree of aggressiveness (Eken Asp et al. 2015;Pérez-Guisado et al. 2006), with the greatest likelihood of occurrence in males especially in contexts aimed to raise reproductive success (Borchelt 1983). This pattern is consistent with the theory of behavioral ecology, predicting that higher levels of aggressiveness have a greater positive outcome for male's fitness (Andersson 1994). ...
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Sex differences in the behavioral responses of Labrador Retriever dogs in the Strange Situation Test were explored. Behaviors expressed by dogs during seven 3-min episodes were analyzed through a Principal Component Analysis (PCA). The scores of factors obtained were analyzed with a Generalized Linear Mixed Model to reveal the effects of the dog’s sex and age and the owner’s sex. In Episode 1 (dog and owner) and 5 (dog alone), the PCA identified three and two factors, respectively, which overall explained 68.7% and 59.8% of the variance, with no effect of sex. In Episodes 2 (dog, owner, and stranger), 3 and 6 (dog and stranger), and 4 and 7 (dog and owner), the PCA identified four factors, which overall explained 51.0% of the variance. Effects of sex were found on: Factor 1 (distress), with lower scores obtained by females in Episode 2 and higher in Episode 3; Factor 2 (sociability), which was overall higher in females; Factor 3 (separation-distress), with females, but not males, obtaining higher scores when left with the stranger than when with the owner. Therefore, females were overall more social but seemed more affected than males by the owner’s absence. Parallels can be traced between our results and sex differences found in adult human romantic attachment, suggesting that the dog-owner bond has characteristics that are not found in the infant-mother relationship.
... Consistent individual behavioral tendencies (personality traits) as a function of sex differences in dogs have been reported. Male dogs appear to express a higher degree of aggressiveness compared to female dogs (Borchelt 1983;Pérez-Guisado et al. 2006;Asp et al. 2015). Aggressiveness is linked to boldness in a specific aggression-boldness syndrome (Sih et al. 2004) and indeed, male dogs appeared to be bolder than female dogs in several experimental contexts (Svartberg 2002;Wilsson and Sundgren 1997;Asp et al. 2015). ...
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This research focuses on sex differences in the behavioral patterns of dogs when they are exposed to human chemosignals (sweat) produced in happy and fear contexts. No age, breed or apparatus-directed behavior differences were found. However, when exposed to fear chemosignals, dogs’ behavior towards their owners, and their stress signals lasted longer when compared to being exposed to happiness as well as control chemosignals. In the happy odor condition, females, in contrast to males, displayed a significantly higher interest to the stranger compared to their owner. In the fear condition, dogs spent more time with their owner compared to the stranger. Behaviors directed towards the door, indicative of exit interest, had a longer duration in the fear condition than the other two conditions. Female dogs revealed a significantly longer door-directed behavior in the fear condition compared to the control condition. Overall the data shows that the effect of exposure to human emotional chemosignals is not sex dependent for behaviors related to the apparatus, the owner or the stress behaviors; however, in the happiness condition, females showed a stronger tendency to interact with the stranger.
... Viewing a puppy with its mother gives prospective owners the opportunity to evaluate (subject to their own experience/knowledge) factors such as the level of maternal care, the general condition and temperament of the mother, and interactions between the mother and puppies. This is particularly important given that studies suggest that characteristics such as fearfulness and anxiety are heritable, [20][21][22] and that offspring of prenatally stressed mothers of a variety of species tend to be more emotionally responsive and take longer to recover from stressful situations. 23 If prospective owners can observe and correctly identify undesirable traits in the mother, it may help them to make informed decisions about whether a puppy may be suitable for their circumstances. ...
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Background Puppy acquisition decisions may impact upon the health and behaviour of these dogs in later life. It is widely recommended by welfare organisations and veterinary bodies that puppies should not leave maternal care until at least eight weeks (56 days) of age, and that when acquiring a puppy it should be viewed with its mother. Methods Owner-reported prospective data were used to explore risk factors for puppy acquisition age, and whether the mother was viewed during acquisition, within a cohort of dog owners participating in an ongoing longitudinal project. Results A quarter (461/1844) of puppies were acquired under eight weeks of age and 8.1 per cent were obtained without viewing the mother (n=149). Only 1.6 per cent of puppies were obtained under eight weeks of age and without the mother being seen (n=30). Multivariable logistic regression analysis revealed that owners who intended their puppy to be a working dog, visited their puppy prior to acquisition, and/or obtained a puppy of unknown breed composition had increased odds of acquiring a puppy under eight weeks of age. The odds also increased as the number of dogs in the household increased but decreased as annual income rose. Owners who visited their puppy prior to acquisition, obtained a Kennel Club registered puppy, viewed the puppy’s father, and/or collected their puppy from the breeder’s home had decreased odds of acquiring a puppy without viewing the mother. Conclusion Targeting interventions towards identified owners who are more likely to acquire a puppy against current recommendations could help reduce these types of acquisitions.
... In contrast, using SNP correlations to estimate the kinship among closely related individuals can lead to inflated heritability (Zaitlen et TA B L E 2 Log-likelihoods and Akaike's information criterion (AIC) for linear mixed models examined Boivin, & Boissy, 1996;Le Neindre et al., 1995;Lovedahl et al., 2005;Morris, Cullen, Kilgour, & Bremner, 1994;Pérez-Guisado, Lopoz-Rodríguez, & Muñoz-Serrano, 2006 (Takahashi & Miczek, 2014). For example, the fear-selected line of silver foxes (Vulpes vulpes) exhibit a strong and heritable aggression response after generations of selection ( Kukekova et al., 2011;Trut, 1980). ...
Article
Aggression is a quantitative trait deeply entwined with individual fitness. Mapping the genomic architecture underlying such traits is complicated by complex inheritance patterns, social structure, pedigree information, and gene pleiotropy. Here, we leveraged the pedigree of a reintroduced population of gray wolves in Yellowstone National Park, Wyoming USA to examine the heritability of and the genetic variation associated with aggression. Since their reintroduction, many ecological and behavioral aspects have been documented, providing unmatched records of aggressive behavior across multiple generations of a wild population of wolves. Using a linear mixed model, a robust genetic relationship matrix, 12,288 SNPs, and 111 wolves, we estimated the SNP‐based heritability of aggression to be 37% and an additional 14% of the phenotypic variation explained by shared environmental exposures. We identified 598 SNP genotypes from 425 gray wolves to resolve a consensus pedigree that was included in a heritability analysis of 141 individuals with SNP genotype, meta‐data, and aggression data. The pedigree‐based heritability estimate for aggression is 14%, and an additional 16% of the phenotypic variation explained by shared environmental exposures. We find strong effects of breeding status and relative pack size on aggression. Through an integrative approach, these results provide a framework for understanding the genetic architecture of a complex trait that influences individual fitness, with linkages to reproduction, in a social carnivore. Along with few other studies, we present here the incredible utility of a pedigreed natural population for dissecting a complex, fitness‐related behavioral trait.
... Sheep, for example, have been bred for improved maternal behaviour (Lambe et al., 2016), whereas beef cattle have been successfully selected for easiness in handling and reduced levels of aggressive behaviour (e.g., Le Neindre et al., 1995). Similarly, several studies have investigated the heritability of aggression-related traits across dog breeds (e.g., Liinamo et al., 2007;Pérez-Guisado et al., 2006), and in animal experimentation, mice have for example been selected to show signs of either high or low stress reactivity (e.g., Touma et al., 2008). Moreover, it has also been shown that it is possible to specifically tackle welfare-related problems, including breeding against abnormal repetitive behaviour, such as stereotypies (e.g., in mink: Jeppesen et al., 2004;in bank voles: Schoenecker and Heller, 2000) or feather pecking (e.g., in laying hens: Jensen et al., 2005;Rodenburg et al., 2010;van Hierden et al., 2002). ...
Article
During the past decades, the study of “animal personalities” has gained increasing importance in the field of behavioural and evolutionary ecology, thereby contributing to a focus shift from the population to the individual in various research disciplines. Against this background, the overall idea of the present review is to transfer the personality concept from behavioural ecology to animal welfare science, to discuss the role of the individual in different research approaches and to pave new grounds for a more individual-tailored assessment and treatment of welfare-related problems. Moreover, we will explicitly refer to welfare issues “beyond the average” thereby addressing problems that are not entirely covered by simply studying personality traits in animal welfare research. By combining two different fields, we hope to stimulate more theoretical and empirical work on this topic to find new ways of improving the welfare of animals in human hands even at the individual level.
... In intraspecific aggression, females appeared to be aggressive predominantly toward other females. Aggression incidences have been reported to be higher in males than in females in many other studies [60][61][62][63][64][65][66]. ...
Article
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In this paper, we review the scientific reports of sex-related differences in dogs as compared to the outcomes described for wild animals. Our aim was to explore whether the differences in male and female dogs were affected by the domestication process, in which artificial selection is the main driver. For this purpose, we used information regarding personality traits, cognitive processes, and perception, for which there is a wide theoretical framework in behavioral ecology. Aggressiveness and boldness, described as a behavioral syndrome, were reported as being higher in males than females. Females also seemed more inclined to interspecific social interactions with humans in tasks that require cooperative skills, whereas males appeared more inclined to social play, thus implying different levels of social engagement between the sexes, depending on the context. Studies on cognitive processes underlined a greater flexibility in resorting to a particular navigation strategy in males. Most lateralization studies seem to support the view that males are preferentially left-handed and females are preferentially right-handed. Reports on visual focusing coherently rank females as superior in focusing on single social and physical stimuli. Only male dogs are able to discriminate kin; however, the timing of the olfactory recording in sexes is related to the stimulus relevance. Dogs are largely in line with life-history theories, which indicate that sex differences in dogs are mainly rooted in their biological and evolutionary heritage, remaining unchanged despite artificial selection. In contrast, the higher intraspecific sociability in wild male animals was not replicated in dogs.
... Confirm whether they have had appropriate worming treatments • Ask to meet the mother (and, if possible, the father) to assess their temperament and general condition. Behavioural traits such as aggression, nervousness and fearfulness have heritable components [7,8] . Equally, if the parents are of a friendly and confident disposition, there is more likelihood that the puppies and kittens will be too. ...
... This work stimulated new scientific interest on the correlation of seemingly unrelated phenotypes in dogs and other species (e.g., Brunberg, Gille, Mikko, Lindgren, & Keeling, 2013;Pérez-Guisado, Lopez-Rodríguez, & Muñoz-Serrano, 2006;Stelow, Bain, & Kass, 2016), and put dogs at the forefront of genetics research (Kubinyi, Sasvári-Székely, & Miklósi, 2011), including work that might contribute to understanding the genetic architecture of human personality (Jensen et al., 2016). Recently, this work inspired psychological research that has informed the theory that the tame temperaments possessed by these foxes and by typical dogs allows for their expression and learning of social-cognitive skills which are similar to some skills possessed by human toddlers (Hare, 2007;Lakatos, Soproni, Dóka, & Miklósi, 2009;Miklósi, Topál, Hare, & Tomasello, 2005). ...
Article
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Five decades ago, Dmitry Belyaev, Lyudmila Trut, and colleagues began a now-famous experiment, selectively breeding foxes based on one criterion: perceived tame behavior. Over generations, the fox population changed in behavior (as predicted) but, intriguingly, also changed markedly in appearance--for example, many had wider mouths, curlier tails, different fur coloring, and floppy ears. These researchers concluded that the morphological changes that appeared in their foxes were a by-product of the researchers' selecting for genetic variants that are implicated both in behavior and in appearance. For decades, scientists have largely accepted this "shared genetic variants" interpretation to fully account for the co-occurrence of behavioral and morphological phenotypes in these foxes and in other domesticated animals. However, several decades of psychological research on human social-cognition, human-canine interaction, and canine behavior strongly suggest that such an account may be incomplete. I forward a supplementary perspective, based on psychological research, that the covariation of appearance and behavior among these foxes may be partly an artifact of human psychological processes at play in selection. These processes include humans' tendency to infer individuals' traits based on their physical features; trait inferences in turn influence how humans treat those individuals. If accurate, this account bears on our understanding of these famous foxes, human-canine interactions, as well as humans' role in domestication.
... In Labrador Retrievers, chocolate dogs were more "agitated when ignored" and showed more "excitability" than black dogs, and lower "trainability" and "noise fear" than both yellow and black dogs (Lofgren et al., 2014). In English Cocker Spaniels, solid-colored dogs were rated as more aggressive than parti-colored dogs, and red and golden dogs were found to be more aggressive than black dogs (Amat, Manteca, Mariotti, de la Torre, & Fatjo, 2009;Perez-Guisado, Lopez-Rodriguez, & Munoz-Serrano, 2006;Podberscek & Serpell, 1996). Fawn-colored Korean Jindo dogs were found to be less fearful and display less submissive reactivity than white dogs (Kim et al., 2010). ...
Article
Coat color influenced the likelihood of a dog being reclaimed from a shelter as well as the length of stay (LOS) of abandoned dogs at the shelter. The shortest LOS was found in brindle and multicolor dogs (median time until adoption: 17 and 18 days, respectively) followed by white, fawn, red, brown, black and tan, and grey dogs. Black dogs had the greatest LOS (median 32 days). In lost dogs, coat color had no significant effect on the time spent at a shelter, the median time until a dog was reclaimed by his/her caretaker being one day, irrespective of the coat color. However, the results of our study suggest that black, brown, and brindle dogs are more likely to be abandoned by their caretakers, and that fawn, black and tan, grey, and red dogs, if lost, have a better chance of being reclaimed by their caretakers.
... This is in line with results from studies of Atlantic salmon and rainbow trout, where selection for divergent hypothalamus-pituitary interregnal responsiveness caused a change in dermal pigmented patterns. Recently, measurements of cortisol levels were conducted on hair from dogs (Pérez-Guisado et al. 2006;Accorsi et al. 2008) and interestingly, differences in cortisol levels in different colored hairs from individual dogs were observed. Red-yellow (pheomelanin) hairs were 4× consistently higher in cortisol levels than black-brown (eumelanin) hairs, with banded, striped bars (agouti) hairs as intermediate (Bennett & Hayssen 2010). ...
Data
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The deleterious effects of heat stress on animal health are being increasingly recognized. This study aimed to determine hair cortisol (HC) and serotonin levels in lactating Holstein cows under heat stress conditions with different coat and hair-cut color. Forty-five multiparous lactating Holstein cows (days in milk = 130 ± 47, body weight = 753 ± 85 kg) were divided to two main groups of over 80% black coat color (BC) and over 85% white coat color (WC) visually observed based on registry certificates and subdividing to black hair sample (BH) and white hair samples (WH) in 2 × 2 factorial arrangements. Hair samples were taken from the forehead of the individuals. Higher HC levels were observed in BC thanWCcows (P<0.05). No differences were found in HC levels between BH and WH groups (P>0.05). Serotonin levels showed no difference between BC and WC (P>0.05). Interaction between coat color and hair color was not significant (P>0.05). The cortisol levels in hair are not affected by pigmentation. However, pigmentation within the coat alters cortisol levels. In conclusion, white coat color retains less cortisol than the black coat. Therefore, white coats are preferable for dairy cows under heat stress conditions.
... Therefore, the aptitude for wild boar hunt in IMSH is not influenced by the colour of coat. Differently, a relationship between coat colour and aggressive behaviour in the case of English cocker spaniels, where animals with a solid coat colour show higher levels of aggression than those that are parti-coloured (Podberscek & Serpell 1996P erez-Guisado et al. 2006;Amat et al. 2009). Also Kim et al. (2010) reported behavioural differences between fawn and white coat Jindo dogs. ...
Article
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This study aimed to evaluate the effect of four non-genetic factors (sex, coat colour, competition judges, type of trial) on the five hunting traits (search, approach, tracking of prey, standstill barking and physical skills) used to estimate the aptitude for wild boar hunt in Italian Maremma Scent Hound. A total of 1147 dogs (734 males, 399 females, and 14 not sexed dogs) were evaluated in competitions held in North-Central Italy, from 2010 to 2011. Dogs were tested as individuals, pairs and packs. Coat colour had no effect on the five tested traits. A significant difference (p < 0.01) between males and females was observed only for search. Type of trial had a significant effect (p < 0.01) on all the five hunting traits. Judges factor was significant (p < 0.01) for physical skills and barking remaining firm in place. A significant positive phenotypic correlation was observed among tracking of prey, approach and physical skills (p < 0.01). Approach and physical skills were positively correlated with approach (p < 0.05) and tracking of prey (p < 0.01). Search was negatively correlated with all the other four, whereas standstill barking showed no correlation with any traits. These data are the basis to improve our knowledge about the values of variability in considered hunting traits and they provide genetic criteria to the breeders to achieve more stringent selective choices.
... This is in line with results from studies of Atlantic salmon and rainbow trout, where selection for divergent hypothalamus-pituitary interregnal responsiveness caused a change in dermal pigmented patterns. Recently, measurements of cortisol levels were conducted on hair from dogs (Pérez-Guisado et al. 2006;Accorsi et al. 2008) and interestingly, differences in cortisol levels in different colored hairs from individual dogs were observed. Red-yellow (pheomelanin) hairs were 4× consistently higher in cortisol levels than black-brown (eumelanin) hairs, with banded, striped bars (agouti) hairs as intermediate (Bennett & Hayssen 2010). ...
Article
Full-text available
The deleterious effects of heat stress on animal health are being increasingly recognized. This study aimed to determine hair cortisol (HC) and serotonin levels in lactating Holstein cows under heat stress conditions with different coat and hair-cut color. Forty-five multiparous lactating Holstein cows (days in milk = 130 ± 47, body weight = 753 ± 85 kg) were divided to two main groups of over 80% black coat color (BC) and over 85% white coat color (WC) visually observed based on registry certificates and subdividing to black hair sample (BH) and white hair samples (WH) in 2 × 2 factorial arrangements. Hair samples were taken from the forehead of the individuals. Higher HC levels were observed in BC than WC cows (P < 0.05). No differences were found in HC levels between BH and WH groups (P > 0.05). Serotonin levels showed no difference between BC and WC (P > 0.05). Interaction between coat color and hair color was not significant (P > 0.05). The cortisol levels in hair are not affected by pigmentation. However, pigmentation within the coat alters cortisol levels. In conclusion, white coat color retains less cortisol than the black coat. Therefore, white coats are preferable for dairy cows under heat stress conditions.
... Aggression can be influenced by genetics and environmental factors. Evidence of genetic effects on aggressive behavior has suggested that there may be breed effects (Amat et al., 2009;Duffy et al., 2008;Hart and Hart, 1985;Liinamo et al., 2007;Pérez-Guisado et al., 2006;Scott and Fuller, 1965). However, many studies have shown a large individual variation in behavior within breeds (Hart and Hart, 1985;Scott and Fuller, 1965;Wilsson and Sundgren, 1998) which indicates that preventive programs should be based on individuals rather than breed, itself. ...
Article
Canine aggression toward family members represents a potential hazard for the owner's health and can severely compromise the welfare of the affected dogs. The aim of this retrospective study was to investigate the main features of canine aggression toward family members using cases from a referral practice. The cases were examined with respect to behavioral and environmental factors that may be related to this problem. Forty-three cases of canine aggression toward family members seen at the Animal Behavior Clinic (Barcelona School of Veterinary Medicine) were analyzed and compared with 50 canine cases with no such history. A logistic regression model was applied to identify environmental and behavioral factors that may be related to aggression toward family members. Dogs adopted before 7 weeks of age and those receiving treats from the table were more likely to present aggression toward family members. Dogs presenting an underlying painful condition were also more likely to be aggressive toward family members. According to the owner's description, most of the dogs showed an ambivalent posture during the aggressive events. These findings provide an insight into some of the factors related to canine aggression toward family members and may help to develop more effective preventive and treatment strategies. Even if causative links cannot be made, our findings certainly provide direction for further investigation.
... However, this is probably due to methodological problems (Houpt and Willis, 2001;Mackenzie et al. 1986). Three more recent studies obtained h 2 estimates between 0.06 and 0.33 for aggression scores in behavioral tests (Courreau and Langlois, 2005;Pérez-Guisado et al. 2006;Saetre et al. 2006). It thus seems that the heritability of aggression is low but significant in the general dog population. ...
Article
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.
... However, this is probably due to methodological problems (Houpt and Willis, 2001;Mackenzie et al. 1986). Three more recent studies obtained h 2 estimates between 0.06 and 0.33 for aggression scores in behavioral tests (Courreau and Langlois, 2005;Pérez-Guisado et al. 2006;Saetre et al. 2006). It thus seems that the heritability of aggression is low but significant in the general dog population. ...
Article
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.
... There have been several recent studies published on the observation that differently coloured individuals of the same species behave differently. Such covariation between colouration and behaviour has not only been reported in a wide range of wild animals, including fish (Kittilsen et al. 2009), reptiles (Mafli et al. 2011), mammals (Trut 1999, Kontiainen et al. 2009) and birds (Sternalski & Bretagnolle 2010, Mateos-Gonzàlez & Senar 2012) but also in domesticated animals (Pérez-Guisado et al. 2006, Bennett & Hayssen 2010, Kim et al. 2010. This suggests that colouration could reveal personality (Réale et al. 2007). ...
Article
Capsule Boldness defines the extent to which animals are willing to take risks in the presence of a predator. Late, but not early, in the breeding season, Israeli nestling Barn Owls displaying larger black feather spots were more docile, feigned death longer and had a lower breathing rate when handled than smaller-spotted nestlings. Larger-spotted breeding females were less docile if heavy but more more docile if light. The covariation between personality (boldness vs. timid) and melanin-based colouration is therefore conditional on environmental factors.
... O cão dominante pode atuar de forma pacífica ou agressiva ao se aproximar de alguém, seja esse alguém um ser humano, um outro cão ou outro animal. Na abordagem agressiva, o cão comporta-se inicialmente com intimidações posturais ou sonoras e posteriormente com ataques direcionados àquele que ameace sua superioridade hierárquica ou a ordem natural da matilha (Overall, 1999). A agressão por dominância é o principal problema de comportamento em cães diagnosticado em serviços de etologia clínica por todo o mundo (Landsberg, 1990). ...
Article
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Campbell, em 1972, desenvolveu um teste para seleção de filhotes de cães, com objetivo de determinar seu grau de dominância para direcioná-los para uma atividade ou família compatível. No presente estudo, o teste de Campbell, tal como ficou conhecido, foi aplicado em filhotes de cinco raças para avaliar possíveis diferenças comportamentais. Os filhotes (138 Labrador; 71 Rottweiler, 31 Bull Terrier, 13 Cocker Spaniel Inglês e 12 Pit Bull), com idade entre seis e oito semanas foram testados em seus canis de origem. Os resultados foram analisados estatisticamente através do teste de Kruskal-Wallis e a comparação entre os pares pelo teste de Mann-Whitney. Os filhotes de Labrador mostraram maior pontuação total no teste comparado aos de Rottweiler (P=0,02) e Bull Terrier (P=0,01). Com esses resultados pode-se caracterizar uma maior atração do filhote de Labrador ou uma maior independência do filhote de Rottweiler e de Bull Terrier em relação ao ser humano, considerando que as etapas do Teste de Campbell que mais evidenciaram a diferença foram àquelas em que o filhote tem que demonstrar interesse pelo examinador.
... Narrow-sense heritability (h 2 ) estimates the additive genetic contribution to a phenotypic trait, such as dogs' social skills (Visscher et al. 2008;Wilson et al. 2011) and this has e.g. been investigated in hunting behaviour (Lindberg et al. 2004), working performance (Ruefenacht et al. 2002), aggression (Liinamo et al. 2007;Perez-Guisado et al. 2006) and some social skills like greeting behaviour (Saetre et al. 2006) and affability (van der Waaij et al. 2008). To our knowledge, no studies have yet investigated the heritability of human-directed social behaviour in dogs raised under standardized conditions. ...
Article
Full-text available
Through domestication and co-evolution with humans, dogs have developed abilities to attract human attention, e.g. in a manner of seeking assistance when faced with a problem solving task. The aims of this study were to investigate within breed variation in human-directed contact seeking in dogs and to estimate its genetic basis. To do this, 498 research beagles, bred and kept under standardised conditions, were tested in an unsolvable problem task. Contact seeking behaviours recorded included both eye contact and physical interactions. Behavioural data was summarised through a principal component analysis, resulting in four components: test interactions, social interactions, eye contact and physical contact. Females scored significantly higher on social interactions and physical contact and age had an effect on eye contact scores. Narrow sense heritabilities (h(2) ) of the two largest components were estimated at 0.32 and 0.23 but were not significant for the last two components. These results show that within the studied dog population, behavioural variation in human-directed social behaviours was sex dependent and that the utilisation of eye contact seeking increased with age and experience. Hence, heritability estimates indicate a significant genetic contribution to the variation found in human-directed social interactions, suggesting that social skills in dogs have a genetic basis, but can also be shaped and enhanced through individual experiences. This research gives the opportunity to further investigate the genetics behind dogs' social skills, which could also play a significant part into research on human social disorders such as autism. This article is protected by copyright. All rights reserved.
... Genes have certainly been demonstrated to play important roles in the expression of behavior in dogs (Scott and Fuller 1965;Mackenzie et al. 1986;Serpell 1987). Attempts to estimate the heritability of canine temperament and performance traits have typically obtained highest values for traits reflecting anxiety/fearfulness, sociability, boldness, and various forms of aggression (Goddard and Beilharz 1982;Liinamo et al. 2007;Pérez-Guisado et al. 2006;Saetre et al. 2006;Scott and Bielefelt 1976;Willis 1995;Wilson and Sundgren 1998). In the present study, a possible direct genetic affect may help to account for the consistently higher levels of fearfulness and reactivity in the small or toy breeds of dog. ...
Chapter
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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. ...
Article
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.
... 73 Heritability of dominance aggression (also called impulse control aggression/conflict aggression) in English cocker spaniels was calculated separately for dam (mother) and sire (father). Dam heritability was greater than that of the sire (0.46 vs 0.20), 74 but the higher heritability in dams includes both maternal genetic and maternal environmental factors in the calculation. Although diagnoses should not be considered phenotypes, they can identify patterns of behavior that can be quantified, and may help create subsequent assessments that can be validated. ...
Article
Phenotyping behavior is difficult, partly because behavior is almost always influenced by environment. Using objective terms/criteria to evaluate behaviors is best; the more objective the assessment, the more likely underlying genetic patterns will be identified. Behavioral pathologies, and highly desirable behavioral characteristics/traits, are likely complex, meaning that multiple genes are probably involved, and therefore simple genetic tests are less possible. Breeds can be improved using traditional quantitative genetic methods; unfortunately, this also creates the possibility of inadvertently selecting for covarying undesirable behaviors. Patterns of behaviors within families and breed lines are still the best guidelines for genetic counseling in dogs.
... Evidence suggests that dogs exhibit relatively stable behavioural predispositions, many of which are reasonably heritable (Perez-Guisado et al., 2006;Spady and Ostrander, 2008;van der Waaij et al., 2008). This means that, in theory, it should be possible to objectively identify the presence or absence of specific behavioural traits considered desirable in modern environments and, further, to use this information to inform breeding and selection choices. ...
Article
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In the past, dogs were bred to perform specific utilitarian roles. Nowadays, the dog's most common role is that of human companion. Our world has changed dramatically since the first dog breeds were developed, yet many of these existing breeds remain popular as companions. While dogs kept as companions can provide a range of benefits to humans, in some cases the relationship between dog and human can be tenuous or even dangerous. Many dogs exhibit behaviours their owners consider undesirable and these dogs may cause disruption and injury to humans and other animals. As a consequence, many are relinquished to shelters. It is proposed that some of this unsuitable behaviour may be the result of inappropriate dog-owner matching, made more likely by the general change in the role of dogs, from working dog to companion animal, coupled with a strong tendency for modern owners and breeders to select dogs primarily on the basis of morphological, rather than behavioural, characteristics. This paper highlights how roles for dogs have changed and the importance of taking physical health and behaviour, as well as perceived beauty, into consideration when breeding and selecting dogs as companions. The measurement of behaviour and limitations of existing canine behaviour assessments are discussed. Finally, it is suggested that scientific development of accurate behavioural assessments, able to identify desirable canine behavioural traits, would provide invaluable tools for a range of dog-related organisations.
Chapter
The range of aggressive behaviors observed in humans cannot be studied in a single animal model, but a spectrum of animal models can facilitate an understanding of the genetic regulation of aggression. This chapter discusses recent discoveries in the genetics of aggression in rodents, canids, and primates. Rodents, often used to study intermale aggression, provide advantages for functional studies using gene modification techniques. Dramatic changes in aggressive behavior, which took place during dog and fox domestication, allow the investigation of a wider array of aggressive behaviors. Finally, studies of individual differences in the behavior of rhesus monkeys and other primates provide insight into developmental aspects of aggression and gene–environment interactions. Although studies of human social behavior using animal models present challenges, a spectrum of such models, each of which provides its own unique information, can work synergistically to yield robust insights into human aggressive behavior.
Chapter
Different tests have been developed for evaluating the temperament of cattle, pigs, and sheep and some studies appear to have conflicting results. This may be due to confusion between the basic emotional systems of fear and separation distress (panic). Methods used for temperament tests can alter results such as how tightly an animal is restrained in a squeeze chute during temperament evaluation. Animals with a more reactive (fearful) temperament will exhibit greater agitated behavioral reactions when suddenly confronted with novel objects. Animals can be habituated to new things but learning is very specific. Habituation to one type of strange object may not transfer to other types of objects. Animals with smaller-diameter leg bones and slender bodies may be more reactive (fearful). Facial hair whorl position is related to a vigilant temperament, and it may be more evident in populations with more diverse genetic backgrounds.
Chapter
Domestic dogs differ enormously in both their morphology and behavior. Numerous factors can influence the development and expression of canine behavior and, more generally, determine the success of the pet–owner relationship. This chapter considers the role of nature and nurture in shaping canine behavior. The influence of factors intrinsic to the animal is outlined, focusing on research that has explored the role of breed, sex, and cerebral lateralization in guiding canine behavior and cognitive functioning. The chapter goes on to consider the role of more extrinsic factors that can influence the development of dog behavior, discussing the contribution of early experience, source of acquisition, training techniques, and owner-related traits including personality and attachment style. The article points to the enormous amount of individual variation that exists between dogs and the myriad of factors that can work together to shape the behavior and functioning of the animal we see before us.
Technical Report
Advice of the French Food Safety Agency on the risk of dog bites and the relevance of breed specific laws made by a subgroup of the Animal Health and Welfare Committee. An evaluation of risk process : identification of the hazard, evaluation of risk i.e emission X expostion and consequences. Advice given on demand of Department of Agriculture related to Laws of 1999, 2007 and 2008 concerning dangerous dogs. Relevance of categorization of dog breeds is discussed as well as the methods of behavioural evaluation.
Article
Subjective beliefs in the personality of a dog based on its breed may result in misinterpretation or scientific bias. Because it has been proven that breed can influence the dog's personality, it is important to determine other genetic factors influencing canine behaviors. The present study investigated behavioral differences of the Jindo dogs based on sex. Thirty-three adult Jindo dogs (21 males and 12 females) were tested in 9 different behavioral subtests, and their behavioral responses to the subtests were recorded using two video cameras. A single blinded observer reviewed the videos and scored the dogs' behaviors from 1-5 based on: sociability, fear, aggression, and submission behaviors. Using the score data, a principal component analysis extracted primary factors: “defensive reactivity toward strangers and novel stimuli,” “nonaggressive reactivity toward a dog and humans,” “social reactivity toward friendly humans and novel stimuli,” “offensive reactivity toward fear evoking humans and novel stimuli,” “social reactivity toward fear evoking humans,” and “nonaggressive and social reactivity toward testing stimuli.” The male and female dogs were compared for the extracted six factors using multivariate analysis of variance. Based on the results, the female Jindo dogs, in contrast to the male dogs, exhibited significantly higher intensity of “nonaggressive reactivity to stranger and novel stimuli.” The results of this study could provide objective information for researchers of canine behavior and supplement baseline data on the Jindo breed. In addition, insight into the Jindo's personality could help potential owners and professional breeders to adapt their training method and expectations of their dogs.
Article
Aggression is the most common dog behavioral problem, with important implications for public health. The aim of this study was to determine the perception of veterinarian clinicians of Montevideo regarding canine aggression, the sex effect, and the main breeds involved. One hundred veterinary clinics of Montevideo city were randomly selected to complete a survey about aggressiveness in dogs. Most veterinarians opined that males are more involved than females in canine aggression and that the Pit bull, the German Shepherd, and Uruguayan Cimarron breeds were the most involved in both types of aggression considered (between canines and towards people), while the Cocker Spaniel breed was involved in aggression towards humans and the Rottweiler breed in aggression between dogs. This work highlights that both veterinarians and other experts within the community identify the Uruguayan Cimarron as being aggressive, which indicates that the behavior of this breed may be of particular concern.
Article
High demand for dogs in countries like the UK can lead to illegal intensive breeding and illegal importation of puppies for the pet trade. The current study investigates the effects of intensive breeding or ‘puppy farming’ on canine behaviour, explores new ways of predicting negative outcomes and categorising dog behaviour, and probes whether various types of training or routines can mitigate these behavioural outcomes. Participants completed an online self-report questionnaire, combining a shortened version of the Canine Behavioural Assessment and Research Questionnaire (mini C-BARQ) (Duffy et al., 2014), with new scales created in collaboration with the Scottish Society for the Prevention of Cruelty to Animals (Scottish SPCA). 2026 participants completed the questionnaire; most owners had dogs from non-puppy farm backgrounds (n = 1702), the rest had dogs from puppy farms (n = 123), or were unsure of the source of the dog (n = 201). We validated the mini C-BARQ as a tool for measuring dog behaviour, and explored its latent dimensions using factor analysis, extracting five first-order factors and one overarching second-order factor. We also confirm the validity of three of the four new scales developed with Scottish SPCA used to measure the impact of puppy farming practices. Linear and logistic regressions demonstrated that dogs from puppy farms have less desirable behaviours than dogs from other sources on 11 of the 14 behavioural subscales of the mini C-BARQ (for significant subscales, coefficients were between 0.1 and 0.2, and odds Ratios between 1.6 and 2.5). Generalized Linear Models (GLM) revealed the predictive power of two newly developed scales measuring early life experience in explaining variations in dog behaviour. In a GLM accounting for the dog's early life experience (and controlling for variables like breed and age), dog-walking significantly reduced the incidence of undesirable behaviours (p < 0.001), while different types of training had a significant interaction with poor early life experience in moderating canine behaviour (p < 0.002). Finally, dogs from puppy farms had significantly worse medical scores than dogs from other breeding sources (U = 144,719, z = 7.228, p < 0.001). These results suggest that puppy farming has negative impacts on dog behaviours and health, while more research is necessary to fully explore how to mitigate the effects of poor early life experience.
Article
Theory stipulates that females should prefer to mate with higher-quality mates to maximize their fitness. As such, traits that females prefer should be honest indicators of male quality. Dominant males are often higher quality, and mating with dominant males may confer indirect fitness benefits to females. Male Jamaican field crickets, Gryllus assimilis, fight more aggressively in front of a female audience than when there is no audience present. Males may increase their aggression because females prefer to mate with males who they have seen win a fight. To test this hypothesis we first allowed females to observe (treatment) or not observe (control) fights and then mated females to either fight winners or losers. We then assessed the following fitness measures: number of eggs oviposited, egg viability, offspring viability and offspring size at adulthood. Neither male fight victory status nor female observer/nonobserver status influenced any of the aforementioned female fitness measures; however, the aggressiveness level of the fight did. Females that mated with males that had participated in more aggressive fights produced offspring that were larger at adulthood. Given that females find larger males more attractive, and larger females oviposit more eggs, these larger offspring may experience greater reproductive success and as a result provide females with indirect fitness benefits.
Article
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In 1972, Campbell developed a test for selection of puppies, aiming to determine their degree of dominance to direct them to a compatible activity or family. In the present study, The Campbell test, as it became know, was applied to puppies from five breeds seeking possible behavioral differences. The puppies (138 Labrador retriever; 71 Rottweiler, 31 Bull Terrier, 13 English Cocker Spaniel and 12 Pit Bull), ranging from six to eight weeks of age, were tested in the kennels where they born. The results were analyzed statistically through the Kruskal-Wallis' test, and the comparison between pairs was done using the Mann-Whiteny's test. The Labrador Retrievers' puppies scored higher when compared to Rottweilers (p= 0,02) and Bull Terriers (p=0,02). These results suggest a higher attraction of the Labrador puppy or a greater independence of the Rottweiler and Bull Terrier puppies in relation to human beings, whereas the steps of the Test of Campbell that showed the most difference were those in which the puppy has to show interest by the examiner.
Article
For many people a good guard dog is a dog that defends aggressively the property that is to say a dog with high levels of territorial aggression. Nevertheless, this advantage can turn into a problem when the dog attacks friends and family, or when the dog disturbs our neighbours with excessive barking at strangers. The study involved carrying out 711 surveys on dog owners. The survey analyses many factors that might be linked to territorial aggression. The results show that there are many factors that are connected to higher levels of territorial aggression and which depend on the owner: not punishing the dog when it does something bad; a high level of education (university studies) and if the animal is acquired as a guard dog. It also found dog-dependent factors associated with territorial aggression: sex (male); certain breeds; FCI groups 5 and 7 and aged between 3 and 7 years. Furthermore, we discovered certain dog behavioural factors that are associated with a higher level of territorial aggression, such as: having as favourite games tug-of-war or bring things, a long time spent eating; if the dog barks a lot; if it attacks strangers randomly; if it tends to bite upper limbs and how nervous the dog is.
Article
Our understanding of the welfare of companion animals is both incomplete and fragmentary. For domestic dogs, most research has focused on animals that do not have stable relationships with people, such as dogs in laboratories and rehoming kennels. The welfare of pet dogs has received limited attention, presumably due to an assumption that owners have their best interests at heart. However, owners' conceptions of their companion's needs can be inconsistent or even contradictory. Dogs are, on the one hand, sentimentalised via anthropomorphic interpretations, but on the other, mythologized as the descendants of savage wolves requiring harsh correction before they will conform to the demands of living alongside people. Canine welfare science attempts to replace such mythos with objective norms that have proved effective when applied to other domesticated species. However, animal welfare science is rarely value-free or unambiguous, since it has variously been defined in terms of physical health, psychological well-being, and the freedom to perform 'natural' behaviour. Here we attempt to strike a balance between each of these approaches while addressing a wide variety of current issues in canine welfare, including: concerns arising from the breeding of pedigree dogs; inappropriate training methods; and the widespread occurrence of behavioural disorders. We finish by describing some barriers to improvement in dog welfare, including owners' anthropomorphisms, the challenges of finding reliable indicators of well-being, and the effects of applying erroneous conceptual frameworks to the dog-owner relationship. © 2014 Springer-Verlag Berlin Heidelberg. All rights are reserved.
Article
Since the first cloned dog "Snuppy" was born, many cloned dogs have been produced by somatic cell nuclear transfer (SCNT) technology. We reported the production of seven cloned drug detection dogs (named "Toppies") in 2009. Although their genetic identity was confirmed, similarities in behavior and the drug-detecting ability were not examined. Therefore, this study is the first attempt to examine their behavior. We conducted the Campbell test which is commonly used to evaluate the tendency of dominance. Data were analyzed by the general linear mixed model. The scores among seven cloned puppies and four naturally-bred controls were significantly different (P < 0.0001). After the test, cloned and control puppies were trained according to the Korea Customs Detector Dog Training Center's manual. The selection rate for detector dog in the cloned puppies was higher (86 %) than that of naturally-bred dogs (30 %). Therefore, it can be concluded that drug detection dogs with high performance can be propagated more efficiently using SCNT.
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A group of ‘low’ (n = 217) and ‘high’ (n = 218) aggression purebred English Cocker Spaniels were compared in relation to demographics and owner interactions. Owners of ‘low’ aggression dogs were more likely to be: older (65 years +; χ2 = 18.753, P < 0.01) and more attached to their dogs (U = 20346, P < 0.001). Dogs in the ‘high’ aggression group were: significantly more likely to be of a solid colour (χ2 = 38.13, P < 0.001); more likely to have been chosen for pet purposes only (χ2 = 25.161, P < 0.001); more likely to have suffered an illness during the first 16 weeks of life (χ2 = 14.899, P < 0.001); groomed less often (t = 2.252, P < 0.05); given less time for walks/exercise (t = 2.618, P < 0.01); slow in obeying commands (U = 17967.5, P < 0.001), more likely to pull on the lead (U = 16663, P < 0.001); and more likely to react to loud or high-pitched noises (χ2 = 14.142, P < 0.001). Factors often quoted to be important in the development of dominance-related aggression, such as feeding the dog before the owner eats, a lack of obedience training, and playing competitive games with the dog, were not found to be significantly different between the two groups. Determining the importance of various factors in the development of canine aggression will enable us to better advise owners in the rearing of their dogs.
Article
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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).
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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.
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Various kinds of aggressive behavior such as spontaneous intermale aggression, predatory aggression (locust-killing behavior), and irritable (shock-induced) aggression were investigated in inbred strains of mice. Genotype was shown to affect significantly the phenotypic variety of these kinds of aggression. There were, however, no interstrain correlations either between intermale aggression and predatory behavior or between intensity of intermale, shock-induced aggression and locust-killing behavior. Moreover, the intermale aggression level (percentage of fighting mice in each strain) did not correlate with the intensity of fighting. It has been shown by Mendelian analysis on C57BL/6J and BALB/c strains that these indices of intermale aggression are under different genetic control. The selection of Norway rats over 20 generations for reduced fear-induced aggressiveness toward man resulted in a decrease in irritable aggression and loss of an aggressive response to man. No changes in intermale and predatory aggression, however, were found. Hence, different kinds of aggressive behavior--intermale, predatory, and fear-induced aggression--seem to be controlled by different genetic mechanisms.
Article
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Artificially selected aggressive (SAL) and non-aggressive (LAL) male house mice were tested in a hexagonal tunnel maze and light-dark preference (LD) box to determine if the bidirectional selection for aggressive behavior leads to a coselection for different levels of trait anxiety. The tunnel maze consists of an open, brightly lit central arena surrounded by a complex system of interconnecting tunnels. As in the LD box, animals which spend less time and are less active in the brightly illuminated section of the maze are considered to have higher anxiety levels. In the tunnel maze, the LAL mice showed more exploration and spent more time in the central arena than the SAL animals, but only during the final 2 min of the 6-min test. This reduced preference for the central arena was not due to general inactivity or a failure of the SAL to find the central arena and indicates a higher level of state anxiety in the aggressive animals. In contrast, no "anxiety-like" differences were found in the LD box, either for the percentage of time spent in the light compartment or for the number of crossings. SAL males actually showed higher levels of moving and rearing, and lower levels of freezing, than did LAL males.
Article
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In 1996, the World Health Assembly declared violence a major public health issue. To follow up on this resolution, on Oct 3 this year, WHO released the first World Report on Violence and Health. The report analyses different types of violence including child abuse and neglect, youth violence, intimate partner violence, sexual violence, elder abuse, self-directed violence, and collective violence. For all these types of violence, the report explores the magnitude of the health and social effects, the risk and protective factors, and the types of prevention efforts that have been initiated. The launch of the report will be followed by a 1-year Global Campaign on Violence Prevention, focusing on implementation of the recommendations. This article summarises some of the main points of the world report.
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This article summarizes the broad individual differences in aggressiveness and its relationship with several other behavioral, physiological, and neurobiological characteristics that exist in an outbred laboratory strain of male feral rats. Based on the observations that the individual level of offensive aggressive behavior (i.e., the tendency to defend the home territory) is strongly related to the way they react to various other environmental challenges, it is argued that the individual's level of offensiveness is an important indicator and component of a more traitlike behavioral physiological response pattern (coping strategy) to environmental demands. The coping style of aggressive animals is principally aimed at a (pro)active prevention or manipulation of a stressor, whereas the nonaggressive individuals tend to passively accept or react to it. The (pro)active and reactive/passive behavioral coping styles are clearly associated with distinct patterns of autonomic/endocrine (re)activity and underlying neurobiological correlates and determinants. Consequently, these individual differences in aggression/coping style may not only determine the individual vulnerability to stress-related disease, and hence be an important factor in the population dynamics of the species, but may also determine responsivity to pharmacotherapeutic treatments. From an animal modeling point of view, it is argued that the aggressive extremes of this variation may, under the proper testing conditions, have an enhanced propensity to develop pathological forms of aggression and/or coping, for example, antisocial traits, violence, or impulsivity disorders. Finally, it is proposed that the use of these feral animals as base "material" for genetic association (i.e., QTL search, mRNA differential expression, nucleic acid microarray analysis) and manipulation (i.e., gene silencing or amplification by antisense ODN, siRNA, and/or viral gene-transfer methodologies) studies would most likely be the best option for dissecting successfully the genetic basis of both normal and pathological forms of aggression and/or coping.
Article
Research has shown that dogs can protect livestock from coyotes (Canis latrans), but information is lacking on comparative effectiveness of dog breeds and on how successfully dogs are being used by livestock producers. We mailed questionnaires to 948 livestock producers in the U.S. and Canada who were likely to be users of livestock guarding dogs. Three hundred ninety-nine written responses were received reporting data on 763 dogs, almost all recognized guarding breeds. Respondents were livestock producers from 47 states and 7 provinces. Producers rated their dogs as very effective (71%), somewhat effective (21%), or not effective (8%) in deterring predation; the majority (82%) said dogs were an economic asset. No particular breed was rated more highly, and the rate of success between males and females was not different. Fifty nonrespondents were telephoned, and although fewer of them had dogs than respondents, their rating of the dogs they used was not significantly different from that of respondents. The data indicate that, when used by producers, livestock guarding dogs are an effective method to manage predation.
Article
The characteristics of 227 biting dogs, their homes, and their victims were gathered in a detailed telephone survey of general veterinary clientele in the Canadian provinces of New Brunswick, Nova Scotia, and Prince Edward Island. All of the dogs had bitten either someone living in the same household, or someone who was a frequent visitor and was well known to the dog. There were 117 male and 110 female dogs included in this case series. Significantly more female dogs were neutered (P=0.03), 58% of the dogs were purebred, and the most commonly reported breed was the Labrador Retriever (n=15). The mean number of people living in each home was 3.13 (S.D.±0.08). Aggression which would traditionally be defined as dominant or possessive had been demonstrated by 75.6% of the dogs in at least one of 17 specific situations outlined in the questionnaire. Dogs with a history of this type of aggression were significantly older (P=0.02) and of lower body weight (P
Article
Hair whorl position on the forehead may be of value in selecting breeding cattle for a calm temperament. A total of 1500 cattle weighing 180–360 kg were temperament rated on a four-point scale. Seventy-two percent of the cattle were European × British breed crosses and 28% were Zebu × dairy breed crosses from Mexico. Cattle with a round hair whorl located above the eyes became significantly more agitated while they were restrained in a squeeze chute (crush) compared to cattle with a hair whorl located either between the eyes or below the eyes. For both the Bos taurus and Bos indicus crossbreeds, animals with hair whorls located below the eyes were rated calmer. There is a positive linear relationship (P < 0.001) between cattle temperament while restrained in a squeeze chute and the location of facial hair whorls. The cattle observed in this study were extensively raised and had a large flight zone when approached by people. Casual observations indicate that the relationship between hair whorl position and temperament is most easily observed in cattle that do not have daily close contact with people.
Article
In 223 cases of dogs presented to a specialist behavioural clinic in Brisbane, Australia, 87 (39%) were for severe aggression. The classes of aggression included dominance (31.6%), territorial (29%), predatory (12.3%), intermale (12.3%), sibling rivalry (7.9%), fear biting (6%) and idiopathic rage (0.9%). The breeds most represented which attacked humans were the Bull Terrier (16%), German Shepherd and crosses (15%), Cattle dog breeds (Blue Heeler and crosses, 9.2%), Terrier breeds (9.2%), Labrador (8%), Poodle and Cocker Spaniel (both 5.7%) and Rottweiler (4.6%). The dangerous dog list put out by the local Brisbane City Council includes the first three breeds mentioned and the Rottweiler as the top four breeds causing aggression problems.Hospital records in Victoria and Queensland confirm that most damage is caused to humans by Bull Terriers and German Shepherds. Many breeds similar to those in our study are also represented in American data on aggressive breeds.Treatments included obedience training only, restraint only, obedience and restraint, synthetic progestins and obedience, castration, progestins and obedience, castration and obedience, use of chlorpromazine and as a last resort, euthanasia (12.6%). Entire males formed the largest group (44%), followed by castrated males and females (both 21%) and spayed females (15%).Several breeds (Boxer, Briand, Samoyed and St. Bernard) only attacked other animals and birds.This study reinforces evidence that social disruption is caused by aggressive dogs, but it also indicates that many responsible clients seek advice on how to deal with this behavioural problem.
Article
Aggression towards owners in a dominance context is a common behavioral problem in dogs. A review of 24 cases (21 males and 3 females) presented to the Veterinary Hospital of the University of Pennsylvania for dominance aggression revealed that it is a predominantly male trait, and pure-bred dogs (n=21) are presented more frequently than are mixed breeds (n=3). Each dog diagnosed as dominant aggressive manifested aggression in three or more of 17 circumstances involving physical manipulation, discipline, or guarding of food, objects or resting places. A combination of techniques including castration, use of synthetic progestins, and behavioral techniques were used to treat the dogs. Three to 15 months after the behavioral consultation, 19 owners were contacted by telephone and interviewed by a person identified as a neutral party unassociated with the service. The owners were asked a standardized set of questions. Twenty-one percent of the owners reported that their dogs were 90% or greater improved, 53% reported a 70% or greater improvement, and 79% reported a 50% or greater improvement. Although the frequency and intensity of aggressive behavior was reduced and the majority of persons were highly satisfied, the dominant aggressive tendencies of the majority of the dogs were not completely suppressed.
Article
Dominance-associated aggression (DA) is a normal, natural, evolutionarily selected trait in many species including the canine species. A review of 35 DA cases presented to a small, private, behavior-only veterinary practice revealed that attention addiction was the most commonly associated (66%) secondary diagnosis. The diagnosis of DA was based on standard criteria. Treatments emphasized owner education and understanding of the problem in addition to common behavior modification, surgical, and pharmacological therapies. The necessity for the owners' gaining psychological leadership in relation to the dog was central to the suggested therapy for 34 of the 35 cases. A phone survey was successful in reaching 34 of the 35 cases. Owners' reports showed that 12% of their dogs showed excellent improvement, 44% reported good improvement, and 32% fair improvement. The owners reported themselves as 97% very or extremely pleased with the quality of information received. These figures and other aspects of canine DA were compared with a similar study done at a large, institutional behavior practice. The results were generally quite similar: DA is predominantly a male trait, found in a wide range of small to large purebred and mixed-bred dogs. DA signs are often apparent in quite young puppies, but do not become of significant concern to most pet owners until the dog is 6 to 24 months old. Both studies supported the concept that DA dogs are reliably responsive to treatment.
Article
The hair whorl is a somatic trait closely related to handedness.
Article
Studies of hair-follicle development and scalp-hair patterning innormal fetuses and children and in those with disorders of early brain development were indicative of the following hypothesis: hair directional slope is secondary to the plane of stretch exerted on the skin by the growth of underlying tissues during the period of downgrowth of the hair follicles, around 10–12 gestational weeks. The posterior parietal hair whorl was interpreted as the focalpoint from which the growth stretch is exerted by the domelike outgrowth of thebrain during the time of hair follicle development. Anomalies such as encephalocele and dicephaly, which must have antedated hair follicle development, showed expected aberrations in scalp patterning. Among patients with primarymicrocephaly 85% had altered scalp hair patterning, indicating an early onsetof the problem in brain development. This included 25% with no parietal whorl, a finding previously noted only in nonhuman primates. Aberrant scalp patterning was also found to be a frequent finding in five established syndromes, included Down syndrome, in each case being compatible with a problem in early brain development. Thus, aberrant scalp-hair patterning may be utilized as an indicator of altered size and/or shape of the brain prior to 12 weeks of gestation.
Article
In order to characterize the three major behavior problems, aggression toward owners, aggression toward strangers and separation anxiety, backgrounds of dogs and general outcomes of the behavioral treatments were analyzed retrospectively. There were 169 cases of aggression toward owners, 84 cases of aggression toward strangers and 78 cases of separation anxiety which did not overlap each other during the 5 years from 1993 to 1997 at Cornell University Animal Behavior Clinic. Based on the case records, including discharge instructions, follow-up information, and pre-presentation questionnaires, several variables were compared among these three groups. The sexual status of these groups was not statistically different, although dogs with aggression toward owners had the highest proportion of males and there were more males in all behavior groups than in the hospital population. Also, breed types were different among three groups with a significantly higher proportion of mixed breed dogs among dogs with separation anxiety and aggression to strangers as compared to dogs with aggression to owners and to the hospital population. A higher percentage of dogs in the separation anxiety group tended to live in apartments and to be disciplined only verbally by the owner than in the other two groups. Age differences were apparent among the three groups in relation to when the dogs were obtained, and the separation anxiety group was different from at least one of the other groups in the age when first obtained, the age the owners first noticed the problem, and the age of behavioral examination. Regarding the general outcome of the behavioral treatment, there were no significant differences among the behavioral groups with regards to the proportion of dogs reported improved. These results provide new characterizations of these three major behavior problems.
Article
In the period 1987–1991 the consultant service established by the Danish Animal Welfare Society and the Danish Civil Dog Training Association reported 3975 problems in relation to pet dogs in Denmark. With nine categories of problem behaviour a total of 2719 problems were recorded in 2238 dogs. The data were analysed for the influence of breed, gender and age on the risk of developing behaviour problems. The analysis was designed as a case-control study using two control groups: (1) dogs registered by Danish Kennel Club in a 5-year period and (2) dogs treated at The Royal Veterinary and Agricultural University, Copenhagen, Denmark in a 4-month period. Thirteen breeds or breed groups including mixed breeds were compared with a reference group consisting of Labrador Retrievers. Compared with the reference group, Alsatians seemed to have higher risks of aggression towards other dogs, aggression towards strangers and general anxiety. For Cocker Spaniels higher risks of aggression towards the owner, aggression towards strangers and indoor urination/defecation were found. Collies seemed to have higher risks of aggression towards strangers, indoor urination/defecation and general anxiety. Furthermore, a higher risk of general anxiety was found in Poodles and Fox Terriers. Generally, Dachshunds, a group consisting of all terriers excluding Fox Terriers and mixed breeds, seemed to have a low risk of behaviour problems. Compared with females, males seemed to have a lower risk of general anxiety and a higher risk of problems related to lack of training and all kinds of aggression. About 80% of the behaviour problems were reported within the first 3 years of life. Only 5.5% of the dogs were suggested to be or were in fact euthanized.
Article
Sexual selection theory suggests that willingness to participate in risky or violent competitive interactions should be observed primarily in those age-sex classes that have experienced the most intense reproductive competition (fitness variance) during the species' evolutionary history, and in those individuals whose present circumstances are predictive of reproductive failure.Homicidal conflicts in the city of Detroit in 1972 are reviewed in the light of the above perspective. Homicide in Detroit, as elsewhere, is overwhelming a male affair. Victim and offender populations are almost identical, with unemployed, unmarried, young men greatly overrepresented. The most common conflict typologies are described, and it is suggested that many, perhaps most, homicides concern status competition.Other manifestations of “taste for risk,” such as daredevilry and gambling are briefly reviewed. The evidence suggests that such a taste is primarily a masculine attribute, and is socially facilitated by the presence of peers in pursuit of the same goals.Such dangerous, competitive acts as the classic “trivial altercation” homicide often appear foolhardy to observers. However, it remains unknown whether the typical consequences of such acts are ultimately beneficial or detrimental to the perpetrators' interests.
Article
Complete case histories from 120 dogs referred because of aggression were reviewed to determine what trends, if any, were present. Sixty percent of the animals were male, with the remaining 40% divided almost equally between females, neutered males, and neutered females. The mean age for dogs presented was 3.0 years, although females tended to be younger and neutered males somewhat older. Mixed-breed dogs (18.3%) were the most common, while Cocker Spaniels and German Shepherds (10% each) were the most commonly seen purebreds. Attacks or threats were directed to adults by 54.2% of the dogs, toward children by 21.7% of the dogs, and toward other dogs by 41.7% of the patients. Twenty animals (16.7%) threatened more than one category. Competitive (dominance) aggression, the most frequent type diagnosed, was expressed by 59.2% of the dogs and was generally responsive to treatment.
Article
The analysis of genetic contributions to aggressive behavior is both conceptually and methodologically difficult, so that substantive findings remain sparse. Like other major psychiatric disease states, inappropriately aggressive behavior must be considered a multifactorial disorder, with both genetic and environmental contributions required for clinical expression. The documented heterogeneity of these determinants suggests the futility of searching for unitary causes. This contribution reviews studies of major gene effects in inbred strains of mice with high aggressivity, and considers the relevance of some rare single-gene disorders in man which include uncontrollably aggressive behavior as part of the phenotype.
Article
Four strains of 'knockout' mice, each with a different gene inactivated, have been found to show increased aggressive behavior. The generation of such knockout strains and quantitative trait locus analysis will help identify the genetic determinants of this complex trait.
Article
MEDFORD, MASSACHUSETTS--Hampered by political, ethical, and methodological problems, a small group of researchers is trying to understand the biological roots of violence. The field has generated some interesting findings and hypotheses about how hormones, genes, and the brain control aggressive behavior. But although the goal is to ultimately find a treatment for violent behavior, researchers emphasize that they are not advocating drugging everybody who has ever committed a crime--or is deemed prone to do so.
Article
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.
Article
Dominance hierarchies were measured in a feeding situation among a mixed group of terriers and beagles who had been reared as mixed litters. In all instances the terriers proved dominant. Choice reactions showed the beagles avoid the terriers but the terriers approach the beagles.
Euthanasia of dogs due to behavioural problems: an epidemiological study of euthanasia of dogs in Denmark, with a special focus on problems of aggressive
  • Mikkelsen
Mikkelsen, J., Lund, J.D., 1999. Euthanasia of dogs due to behavioural problems: an epidemiological study of euthanasia of dogs in Denmark, with a special focus on problems of aggressive. Eur. J. Companion Anim. Pract. X, 143-150.
Hondenbeten en huisartsbehandelingen: Ernst, omvang en toedrachten van honderbeten benhandeld door huisartsen
  • H Toet
  • P C Den Hertog
Toet, H., Den Hertog, P.C., 2000. Hondenbeten en huisartsbehandelingen: Ernst, omvang en toedrachten van honderbeten benhandeld door huisartsen. Report Stichting Consument en Veiligheid.
Como elegir tu primer perro. De Vecchi, SA
  • V Rossi
Rossi, V., 1992. Como elegir tu primer perro. De Vecchi, SA, pp. 153-160.
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