Ability of the Public to Recognize Dogs Considered to Be Dangerous under the Dangerous Dogs Act in the United Kingdom

Canine aggression came into the public eye in the United Kingdom in the late 1980s prompting enactment of the UK Dangerous Dogs Act , which prohibits four breeds or “types” of dogs. The act faced strong opposition surrounding correct identification of prohibited dogs. A questionnaire was distributed to the public via an online platform, especially targetting those who have worked with dogs. The questionnaire assessed respondents’ abilities to identify the four banned types of dogs from other breeds and their capability to identify Pit Bull Terrier types from other similar dog types. Identification of both banned breeds, F(1, 20) = 57.746, p < .001, and bull breeds, F(1, 20) = 9.293, p = .006, was significantly lower than identification of other breeds. Recognition of Pit Bull Terrier types from similar types of dogs was generally poor, although people in a dog-related profession, as opposed to those in other professions, could correctly distinguish more pit bull-type dogs (U = 46,164.0, n₁ = 187, n₂ = 575, p = .003). Findings suggest public understanding of dangerous dogs is poor, and it may impact societal perceptions of dogs more widely.     

A breed-matched case-control study of potential risk-factors for canine pyometra

The objective was to evaluate plausible risk-factors for pyometra, a common disease affecting almost 25% of all (unspayed) female dogs before 10 years of age. Because of the strong breed-predilection, an age- and breed-matched case-control study was undertaken on 87 pairs (pyometra-cases and healthy controls) from five breeds (Rottweiler (n = 13), Collie (n = 8), Golden retriever (n = 24), Labrador retriever (n = 16) and German shepherd dog (n = 26)). The mean age was 7.9 y (range 0.8-13.8 y). Variables analyzed included pseudopregnancy, age at first oestrus, length of and regularity of the interoestrus interval, hormone treatments, nulliparity, number of parities, age at first whelping, previous urinary tract infections and mammary tumours. Data were modelled multivariably using matched-pair conditional logistic regression. Analysing interactions with breed, previous pregnancy was statistically associated with pyometra. When amalgamated, in three breeds previous pregnancy was protective (Rottweiler, Collie, Labrador retriever) and in one breed statistically intermediate (German shepherd dog) when compared to the baseline (Golden retriever). Previous pregnancy was a statistically significant factor that had a protective effect against pyometra in some breeds but not in the Golden retriever breed. These findings indicate that protective- and risk-factors may vary between different breeds. The obvious problem with low power and limited possibility for extrapolation, using few dogs in few breeds, is acknowledged. However, it is suggested that failure to control for the confounding effect of breed, especially in epidemiological studies on dog diseases, may lead to potentially erroneous conclusions.     

The genetic contribution to canine personality

The domestic dog may be exceptionally well suited for behavioral genetic studies owing to its population history and the striking behavior differences among breeds. To explore to what extent and how behavioral traits are transmitted between generations, heritabilities and genetic correlations for behavioral traits were estimated in a cohort containing over 10,000 behaviorally tested German shepherd and Rottweiler dogs. In both breeds, the pattern of co-inheritance was found to be similar for the 16 examined behavioral traits. Furthermore, over 50% of the additive genetic variation of the behavioral traits could be explained by one underlying principal component, indicating a shared genetic component behind most of the examined behavioral traits. Only aggression appears to be inherited independently of the other traits. The results support a genetic basis for a broad personality trait previously named shyness-boldness dimension, and heritability was estimated to be 0.25 in the two breeds. Therefore, breeds of dogs appear to constitute a valuable resource for behavioral genetic research on the normal behavioral differences in broad personality traits.     

Genetic diversity of dog breeds: within-breed diversity comparing genealogical and molecular data

The genetic diversity of 61 dog breeds raised in France was investigated. Genealogical analyses were performed on the pedigree file of the French kennel club. A total of 1514 dogs were also genotyped using 21 microsatellite markers. For animals born from 2001 to 2005, the average coefficient of inbreeding ranged from 0.2% to 8.8% and the effective number of ancestors ranged from 9 to 209, according to the breed. The mean value of heterozygosity was 0.62 over all breeds (range 0.37–0.77). At the breed level, few correlations were found between genealogical and molecular parameters. Kinship coefficients and individual similarity estimators were, however, significantly correlated, with the best mean correlation being found for the Lynch & Ritland estimator ( r  =   0.43). According to both approaches, it was concluded that special efforts should be made to maintain diversity for three breeds, namely the Berger des Pyrénées, Braque Saint-Germain and Bull Terrier.     

Erythrocyte surface sialic acid levels of clinically healthy mongrel and exotic (alsatian and terrier) breeds of dogs

The erythrocyte surface sialic acid concentration of clinically healthy mongrel and exotic (Alsatian i.e. German shepherd and Terrier) breeds of dogs was analyzed in order to determine their role in the genetic resistance of these breeds of dogs to diseases that cause anaemia. The mean erythrocyte surface sialic acid (ESA) concentration was 57.08 ± 1.67, 34.50 ± 2.30 and 20.20 ± 3.54 mg/dl for Mongrel, Alsatian (German shepherd) and Terrier breeds of dogs, respectively, on acid hydrolysis. The mean values of ESA obtained following enzymic hydrolysis of haemoglobin-free erythrocyte membranes using Clostridium chauvoei (Jakari strain) sialidase were 49.08 ± 0.41, 30.97 ± 1.82 and 18.64 ± 0.75 mg/dl for Mongrel, Alsatian (German shepherd) and Terrier dogs respectively. When Trypanosoma vivax sialidase was used the ESA values obtained were 50.81 ± 0.37, 41.70 ±  0.94 and 19.65 + 0.65 mg/dl for Mongrel, Alsatian (German shepherd) and Terrier breeds of dogs respectively. This represents a statistically significant difference (P < 0.001) between the mean ESA concentration of all the breeds of dogs investigated in this study. The higher mean ESA concentration in Mongrel dogs, compared to the exotic breeds may be responsible for their resistance to disease conditions, whose aetiologic agents produce neuraminidase and also cause anaemia.     

What Makes a Dog Adoptable? An Eye-Tracking Investigation

Humans readily attribute personality and behavioral traits to dogs, and these attributions influence decisions about adoption. This study focused on how these attributions could be influenced by breed and pose by using pictures of four breeds (Doberman Pinscher, Golden Retriever, pit bull, and Rottweiler) in 4 poses (dog sitting alone, sitting with a human, standing alone, and walking on a leash with a human). Participants rated each picture on friendliness, aggressiveness, and adoptability. Eye-tracking technology identified which specific features were represented in each picture to determine whether they had any effect on the judgments. Although the Golden Retriever was seen as most adoptable, pose differences had many significant effects that could be useful for increasing the adoptability of all breeds. Data also revealed facial areas that attracted more attention (e.g., faster time to first fixation and longer fixation duration), particularly when the dog was alone. Focus on these areas could help to optimize photographs to present dogs in the friendliest, least aggressive, and most adoptable way.     

Effects of Video Footage Versus Photographs on Perception of Dog Behavioral Traits

Photographs are frequently used to promote adoption of dogs on rescue shelter websites. While physical traits are well illustrated via photographs, conveying a dog's behavioral traits is more problematic. Traits such as sociability, obedience, and friendliness are likely to be better displayed via video footage. This study explored the effects of video versus photographs on the perception of dog behavioral traits. Four dogs from a Gloucestershire Rescue Shelter (2 desirable breeds, 2 from a stigmatized breed) were individually photographed, and a 30-s video of each was recorded. Two questionnaires were produced containing either a video or photograph of each dog. Each questionnaire presented all 4 dogs but via different media. Participants rated their agreement with 12 statements relating to their perceptions of the dog seen. Dogs viewed via video were considered to be more trainable, intelligent, friendly, and gentle and less dominant, aggressive, and unsociable. This finding was observed in desired and stigmatized breeds. Perceived behavioral traits can impact the likelihood of adoption. These findings suggest that greater use of video footage by rehoming shelters could help promote dog adoptions.     

The Effect of Priming on Perceptions of Dog Breed Traits

ABSTRACT

This study examined whether priming cues embedded in mediastyle presentations shaped people's perceptions of specific dog breeds, and in particular, the German shepherd dog (GSD). Two hundred and four adult females were exposed to one of two types of media-style presentation (stories or pictures). Half of the participants in each condition were exposed to versions designed to portray the GSD in a positive light; the remainder to stimuli developed to present the same breed in a negative light. Participants subsequently rated six individual breeds of dog, including the target breed, on a number of traits (e.g., “friendliness,” “aggression”). Analysis revealed a significant effect of priming on people's perceptions of the GSD. Participants exposed to the negative stimuli perceived this breed as significantly less approachable, and more dangerous and aggressive, than those exposed to the positive stimuli. Priming did not influence the participants' perceptions of other breeds, even those often regarded in a negative light, although there was some evidence of breed-related category-based stereotyping. Overall, results suggest that people's perceptions of dog breeds can be influenced by verbal and visual representations. The results have implications for how dogs are portrayed in the media and other publically available sources of information.     

Dog breed stereotype and exposure to negative behavior: effects on perceptions of adoptability

The purpose of the study was to determine if brief exposure to a dog behaving badly or in a friendly manner affects subsequent perceptions of the target dog's and other dogs' adoptability. Participants viewed a videotape of an adoptable German shepherd behaving either aggressively or prosocially and were then asked to rate the characteristics and adoptability of the same and different dogs. The results showed that people who saw the aggressive behavioral schema perceived only the target dog and a dog of the same breed to be significantly less adoptable than dogs of other breeds (p<.01). Results of a principal components analysis showed participants perceived the adoptability of dogs to be related to "sociability": Adoptable dogs were more approachable, friendly, intelligent, and less dangerous and aggressive (p<.01). Brief exposure to a misbehaving dog prior to making a decision to adopt may unfairly penalize other dogs perceived to be similar to the misbehaving dog.     

Preliminary observations on the characteristics of the owned dog population in Roseau, Dominica

This article reports findings from interviews with 93 heads of households (38.6% of all households) who owned 148 dogs in Roseau, the capital of The Commonwealth of Dominica. Mixed dogs, of no definable cross, were most common, followed by Rottweiler crosses. The median age of the dogs was 3 years, and 9.4% of the population was over 7 years. Respondents showed a definite preference for keeping male dogs (60%), and most animals were kept for protection (65%). Almost 30% of the dogs were allowed to roam. With 8.5% of the dogs neutered and 7 puppies per litter being born, the owned population produces more dogs than are required to maintain its size and so can provide recruits to the “stray” dog population. Comparisons with studies elsewhere in the Caribbean region (Fielding & Plumridge, 2005; Ortega-Pacheco et al. (in press) suggest that environmental effects rather than the level of care offered are primarily responsible for controlling the dog population.     

Canine COL4A3 and COL4A4: sequencing, mapping and genomic organization.

Canine alpha3 and alpha4 chains of collagen type IV genes (COL4A3 and COL4A4) are expressed in the renal glomerular basement membrane, where they provide a critical structural and functional matrix for other basement membrane components. These genes are candidates for hereditary nephritis (Alport syndrome) in several dog breeds (e.g. English Cocker Spaniel and Bull Terrier). Using RACE and PCR, the cDNA of both genes was cloned and sequenced. Both COL4A3 and COL4A4, as well as canine NPPC (Natriuretic Peptide Precursor C), were mapped to CFA25 using an RH panel. Conservation of the tight linkage of COL4A3 and COL4A4 as seen in human and mouse was verified in the dog. Intron-exon boundaries in both genes were determined by BLAST analysis of the Canis Familiaris Trace Archive. The elucidation of the cDNA sequences, genomic organization and the open reading frames of canine COL4A3 and COL4A4 provide the groundwork for screening these genes for mutations in hereditary nephritis in dogs.     

Dog Breed Stereotype and Exposure to Negative Behavior: Effects on Perceptions of Adoptability

The purpose of the study was to determine if brief exposure to a dog behaving badly or in a friendly manner affects subsequent perceptions of the target dog's and other dogs' adoptability. Participants viewed a videotape of an adoptable German shepherd behaving either aggressively or prosocially and were then asked to rate the characteristics and adoptability of the same and different dogs. The results showed that people who saw the aggressive behavioral schema perceived only the target dog and a dog of the same breed to be significantly less adoptable than dogs of other breeds (p < .01). Results of a principal components analysis showed participants perceived the adoptability of dogs to be related to “sociability”: Adoptable dogs were more approachable, friendly, intelligent, and less dangerous and aggressive (p < .01). Brief exposure to a misbehaving dog prior to making a decision to adopt may unfairly penalize other dogs perceived to be similar to the misbehaving dog.     

Origin and phylogenetic analysis of Tibetan Mastiff based on the mitochondrial DNA sequence

At present, the Tibetan Mastiff is the oldest and most ferocious dog in the world. However, the origin of the Tibetan Mastiff and its Phylogenetic relationship with other large breed dogs such as Saint Bernard are unclear. In this study, the primers were designed according to the mitochondrial genome sequence of the domestic dog, and the 2,525 bp mitochondrial sequence, containing the whole sequence of Cytochrome b, tRNA-Thr, tRNA-Pro, and control region of the Tibetan Mastiff, was obtained. Using grey wolves and coyotes as outgroups, the Tibetan Mastiff and 12 breeds of domestic dogs were analyzed in phylogenesis. Tibetan Mastiff, domestic dog breeds, and grey wolves were clustered into a group and coyotes were clustered in a group separately. This indicated that the Tibetan Mastiff and the other domestic dogs originated from the grey wolf, and the Tibetan Mastiff belonged to Carnivora, Canidae, Canis, Canis lupus, Canis lupus familiaris on the animal taxonomy. In domestic dogs, the middle and small breed dogs were clustered at first; German Sheepdog, Swedish Elkhound, and Black Russian Terrier were clustered into one group, and the Tibetan Mastiff, Old English Sheepdog, Leonberger, and Saint Bernard were clustered in another group. This confirmed the viewpoint that many of the famous large breed dogs worldwide Such as Saint Bernard possibly had the blood lineage of the Tibetan Mastiff, based on the molecular data. According to the substitution rate, we concluded that the approximate divergence time between Tibetan Mastiff and grey wolf was 58,000 years before the present (YBP), and the approximate divergence time between other domestic dogs and grey wolf was 42,000 YBP, demonstrating that the time of origin of the Tibetan Mastiff was earlier than that of the other domestic dogs.     

"Bark parks"--a study on interdog aggression in a limited-control environment

As limited-control dog parks become more popular, concerns arise about whether these parks encourage interdog aggression. Systematic observations made at 1 park over 72 hr across 8 months found that 28 conflicts or potential conflicts occurred (< 0.5%). Of these, 14 were clear aggressive episodes. Each lasted less than 1 min (< 0.33% of total observation time). There were 14 other incidents of possible aggression that were ambiguous in nature. Each lasted less than 30 sec (< 0.17%). None of these incidents led to serious injury. Of the 177 dogs observed, only 9 were aggressive toward other dogs (5%): 6 aggressors, once each; 2 aggressors, twice each; 1 aggressor, 3 times. Results indicate that aggression in limited-control dog parks may be relatively rare and probably presents only a limited risk to dogs and their caregivers (owners). In part, this may be because owners who frequent dog parks are self-selecting, self-monitoring, and self-limiting in regard to dog aggression.     

"Bark Parks"-A Study on Interdog Aggression in a Limited-Control Environment

As limited-control dog parks become more popular, concerns arise about whether these parks encourage interdog aggression. Systematic observations made at 1 park over 72 hr across 8 months found that 28 conflicts or potential conflicts occurred (< 0.5%). Of these, 14 were clear aggressive episodes. Each lasted less than 1 min (< 0.33% of total observation time). There were 14 other incidents of possible aggression that were ambiguous in nature. Each lasted less than 30 sec (< 0.17%). None of these incidents led to serious injury. Of the 177 dogs observed, only 9 were aggressive toward other dogs (5%): 6 aggressors, once each; 2 aggressors, twice each; 1 aggressor, 3 times. Results indicate that aggression in limited-control dog parks may be relatively rare and probably presents only a limited risk to dogs and their caregivers (owners). In part, this may be because owners who frequent dog parks are self-selecting, self-monitoring, and self-limiting in regard to dog aggression.     

Identification of the mutation causing progressive retinal atrophy in Old Danish Pointing Dog

Progressive retinal atrophy (PRA) is a common cause of blindness in many dog breeds. It is most often inherited as a simple Mendelian trait, but great genetic heterogeneity has been demonstrated both within and between breeds. In many breeds the genetic cause of the disease is not known, and until now, the Old Danish Pointing Dog (ODP) has been one of those breeds. ODP is one of the oldest dog breeds in Europe. Seventy years ago the breed almost vanished, but today a population still exists, primarily in Denmark but with some dogs in Germany and Sweden. PRA has been diagnosed in ODP since the late 1990s. It resembles late onset PRA in other dog breeds, and it is inherited as an autosomal recessive trait. In the present study, we performed whole‐genome sequencing and identified a single base insertion (c.3149_3150insC) in exon 1 of C17H2orf71. This is the same mutation previously found to cause PRA in Gordon Setters and Irish Setters, and it was later found in Tibetan Terrier, Standard Poodle and the Polski Owczarek Nizinny. The presence of the mutation in such a diverse range of breeds indicates an origin preceding creation of modern dog breeds. Hence, we screened 262 dogs from 44 different breeds plus four crossbred dogs, and can subsequently add Miniature Poodle and another polish sheepdog, the Polski Owczarek Podhalanski, to the list of affected breeds.     

Behavioural changes and aversive conditioning in hunting dogs by the second-year confrontation with domestic sheep

Domesticated dogs occasionally exhibit predatory behaviour towards domestic sheep when running loose in pasture. Both young and old dogs of either sex may chase sheep. Electronic dog collars applying electric shocks are utilised as one method of training dogs to refrain from attacking sheep. This device is used for a number of other training purposes which have raised concern for the welfare of the dogs being trained. This study aims at testing long-term learning effects of previous sheep tests on sheep chasing in hunting dog breeds (Norwegian elkhounds (grey), English setters, and hare hunting dogs), in particular with use of electronic dog collars, in addition to uncovering potential secondary negative effects on dogs' behaviour and mental stability. The dogs (N=114) were subjected to three tests for two subsequent years, the second year being reported here. Dogs were tested for reactions to different stimuli, including a sheep, in a path test. In a sheep confrontation test, dogs were fenced in with a sheep group and given el. shocks when approaching 1-2m from sheep. A questionnaire to the dog owners reported differences in dogs' behaviour between the years.Dogs showed weaker or delayed behavioural responses in both tests in the second year. No dogs showed interest in or attacked a lone sheep in the path test in the second year, while almost two thirds of them did so the first year. In the sheep confrontation test, the dogs exhibited comparatively hesitant initial hunting motivation the second year, being more evident in dogs which received el. shocks the first year. No dogs chased or attacked sheep as their first response in this test, while half of them did so the first year. The proportion of dogs attacking sheep during the entire test was reduced to almost one fourth. The number of el. shocks administered reduced by the second year, and only one of the dogs that received el. shocks the first year received el. shocks the second year. The owners reported no negative effect on the dogs' behaviour during the year ensuing el. shock treatment. Eighteen of the 24 dogs reported by owners to exhibit behavioural changes lost their previous interest in sheep.The second-year tests indicate that aversive conditioning with the use of electronic dog collar may be an efficient method for reducing the probability of a dog chasing or attacking grazing sheep. No adverse effects were observed with our test procedure.     

Evaluation of RDS/Peripherin and ROM1 as candidate genes in generalised progressive retinal atrophy and exclusion of digenic inheritance

Generalised progressive retinal atrophy (gPRA) is a heterogeneous group of hereditary diseases causing degeneration of the retina in dogs and cats. As a combination of mutations in the RDS/Peripherin and the ROM1 genes leads to the phenotype of retinitis pigmentosa in man we first performed mutation analysis to screen these genes for disease causing mutations followed by the investigation of a digenic inheritance in dogs. We cloned the RDS/Peripherin gene and investigated the RDS/Peripherin and ROM1 genes for disease causing mutations in 13 gPRA-affected dog breeds including healthy animals, obligate gPRA carriers and gPRA-affected dogs. We screened for mutations using single strand conformation polymorphism (SSCP) analysis. Sequence analysis revealed several sequence variations. In the coding region of the RDS/Peripherin gene three nucleotide exchanges were identified (A277C; C316T; G1255A), one of which leads to an amino acid substitution (Ala339Thr). Various silent sequence variations were found in the coding region of the ROM1 gene (A536G, G1006A, T1018C, T1111C, C1150T, C1195T), as well as an amino acid substitution (G252T; Ala54Ser). By excluding the respective gene as a cause for gPRA several sequence variations in the intronic regions were investigated. None of these sequence variations cosegregated with autosomal recessively (ar) transmitted gPRA in 11 breeds. The candidate gene RDS/Peripherin obviously does not harbour the critical mutation causing the autosomal recessive form of gPRA because diseased individuals show heterozygous genotypes for sequence variations in the Miniature Poodle, Dachshund, Australian Cattle Dog, Cocker Spaniel, Chesapeake Bay Retriever, Entlebucher Sennenhund, Sloughi, Yorkshire Terrier, Tibet Mastiff, Tibet Terrier and Labrador Retriever breeds. In the following breeds the ROM1 gene was also excluded indirectly for gPRA: Miniature Poodle, Dachshund, Australian Cattle Dog, Sloughi, Collie, Tibet Terrier, Labrador Retriever and Saarloos/Wolfhound. Digenic inheritance for gPRA is practically excluded for both these genes in four breeds: Miniature Poodle, Dachshund, Labrador Retriever and Saarloos/Wolfhound.     

Identification of a novel germline MET mutation in dogs

The MET proto-oncogene encodes a transmembrane tyrosine kinase receptor that mediates multiple functions such as migration, cycling and survival by binding to hepatocyte growth factor (HGF). Dysregulation of MET through inappropriate expression or mutation has been shown to play an important role in human cancers. Furthermore, inherited mutations in MET are known to contribute to the development of gastric and renal cancer in humans. Lastly, mouse models of MET mutations lead to the development of a wide variety of cancers including lymphomas, sarcomas and some forms of carcinoma. In the process of cloning canine MET, a novel germline point mutation was found in the juxtamembrane domain (G966S) in two of the templates used for cloning, both of which were derived from Rottweiler dogs, a breed believed to be at high risk for the development of several cancers. Screening of germline DNA from a variety of breeds revealed that this mutation was present in approximately 70% of Rottweiler dogs and <5% of all other breeds examined, suggesting a breed-specific heritable mutation. Stable transfection of the G966S mutant form of MET into NIH3T3 cells resulted in enhanced baseline scattering and migration of the cells, which was further increased in the presence of HGF. This study supports the notion that particular dog breeds may carry germline mutations that contribute to high rates of cancer in a manner similar to heritable, cancer-associated mutations in humans.     

Variability of canine microsatellites within and between different dog breeds

Polymorphic animal microsatellites have proved valuable genetic markers. For this project, the variability of 19 canine microsatellite loci was examined within and between three pure breeds of dog: Greyhounds, Labradors, and German Shepherds. The number of alleles, absolute and relative frequencies, and the statistics that express polymorphism within a breed were determined. The evolutionary relationships among these closely related dog breeds were estimated by genetic distance measures developed for use with microsatellite loci. According to the pairwise genetic distances, Greyhounds and German Shepherds had longer diverse evolutionary histories than Greyhounds and Labradors or Labradors and German Shepherds. Although a few breed-specific alleles were observed, the significant differences between breeds are in their relative frequencies and distribution of the alleles across a locus. None of the three pure dog breeds corresponds to Hardy-Weinberg equilibrium. A considerable reduction in intrapopulation variation was observed within three pure breeds, compared with the population of individuals belonging to 15 dog breeds. This reduction was especially pronounced in the Greyhound breed, which expressed the lowest degree of variation. Intrapopulation variations of Labradors and German Shepherds did not differ significantly, that of Labradors being only slightly higher. The intra-species variation of dogs is lower than in humans, mouse, or rat, but similar to that in domestic animals, probably reflecting similarly high inbreeding coefficients. However, some highly informative loci were common to all dog breeds tested so far. Such population data are necessary for mapping studies and linkage analysis in dogs. Received: 31 July 1996 / Accepted: 21 October 1996