FEATURE | FACTORS ASSOCIATED WITH AGGRESSION
View all journals Search My Account dogs were more than twice as likely to be aggressive than non-fearful dogs .
Other findings of this research included that older dogs were more likely to behave aggressively towards people than younger dogs . Possible explanations for this correlation include older dogs experiencing more pain due to age-related physical conditions . Another explanation is that an older dog has simply had more time to behave aggressively .
Another finding , with a small effect size , was the owner ’ s dog experience . Dogs living with owners who had had at least one dog before were a little less likely to show aggression . The researchers suggest several explanations for this . First , experienced owners may be more aware of the importance of socialization . They may also be quicker to identify problems , and therefore start behavior interventions sooner . Finally , experienced owners who had a previous dog who showed aggression may simply be picking dogs more carefully . Another factor with a somewhat larger effect size in this research was the sex of the dog . The researchers saw much higher rates of aggression toward people in male dogs than in female dogs . Other research has been mixed on this topic , though , so the authors remind us that more research is still needed to help sort out the associations between sex and rates of aggressive behavior .
One more interesting factor was whether the dog lived alone or in a multi-dog household . While the correlation was not strong , the data from this study do suggest that dogs who live with other dogs are less likely to show aggression towards people . A similar correlation has been seen in previous research , too .
There are a couple of other things to note : Due to the nature of the data they got , the researchers were not able to examine aggressive behavior towards family members vs . aggressive behavior towards strangers separately . They also did not have any information on the health of the dog . content About Publish Sign up for alerts RSS feed
Table 3 The variables and their categories used in the model selection of aggressive behaviour .
From : Aggressive behaviour is affected by demographic , environmental and behavioural factors in purebred dogs
Variable
Aggressive behaviour
Age Sex Sterilisation
Fearfulness
Urban environment score
Body size
Variable
Breed
Weaning age
Family size
Dogs in the family
Owner ’ s dog experience
Daily exercise
Daily time spent alone
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Explanation
Binary ( event / non-event ) variable . Dogs in the high aggressive behaviour group had tried to bite or snap at least sometimes or growled at least often ( event ). Dogs in the low aggressive behaviour group had never shown these signs of aggressive behaviour ( non-event )
Numerical variable . Reported current age of the dog in years Binary variable . Reported sex of the dog . 1 : male , 2 : female Binary variable . Reported status of the dog . 1 : intact , 2 : neutered
Ordinal variable . Dogs were divided into three fearfulness groups . High group included dogs which had shown fear of strangers , dogs or novel situations at least often ( 40 – 60 % of the times ). Moderate group included dogs that had shown fear rarely or sometimes ( 0 – 40 % of the times ) or had growled or barked in these situations . Low group included dogs which had never shown fear in these situations
Numerical variable . The environmental land-use around the dog ’ s home . The coverage of three land-use types ( artificial surfaces , agricultural areas , forests and semi-natural areas ) was calculated within a three-kilometre range around the homes . The coverages were simplified into one numerical variable , in which a higher value indicates a more urban environment
Ordinal variable . Dogs were divided into categories based on the average height of the breed . 1 : small ( ≤ 35 cm ), 2 : medium ( 36 – 49 cm ), 3 : large ( ≥ 50 cm )
Explanation
Categorical variable . Reported breed of the dog . Border Collie , Cairn Terrier , Chihuahua ( short haired and long haired ), Chinese Crested Dog , Coton de Tulèar , Finnish Lapponian Dog , German Shepherd Dog , Golden Retriever , Irish Soft Coated Wheaten Terrier ( labelled Wheaten Terrier ), Jack Russell Terrier , Labrador Retriever , Lagotto Romagnolo , Lapponian Herder , Medium size Spitz , Miniature Poodle ( toy , miniature , and medium sized ), Miniature Schnauzer , Pembroke Welsh Corgi , Rough Collie , Shetland Sheepdog , Smooth Collie , Spanish Water Dog , Staffordshire Bull Terrier , other
Ordinal variable . The reported weaning ages were divided into four categories . 1 : < 7 weeks of age , 2 : at 7 weeks of age , 3 : at 8 weeks of age , 4 : > 8 weeks of age
Ordinal variable . The size of the family in which the dog lives . 1 : single , 2 : couple , 3 : family with one or two adults and one child , 4 : family with one or two adults and two children , 5 : family with three or more adults and / or three or more children
Binary variable . Describes whether there are other dogs in the family . 1 : the dog is the only dog in the family , 2 : the dog lives with one or more dogs
Binary variable . Describes owner ’ s experience with dogs . 1 : the dog is the owner ’ s first dog , 2 : the owner has had dogs before this dog
Ordinal variable . Describes the amount of dog ’ s daily exercise in hours . 1 : < 1 h , 2 : 1 – 2 h , 3 : 2 – 3 h , 4 : > 3 h
Ordinal variable . Describes the daily time that dog spends alone at home without the presence of people . 1 : < 3 h , 2 : 3 – 6 h , 3 : 6 – 8 h , 4 : > 8 h
Scientific Reports ( Sci Rep ) ISSN 2045-2322 ( online )
All in all ( or “ in toto ,” as is often said in scientific settings ), this research largely confirms findings of previous similar studies , and reminds us that aggressive behavior is a complex trait with many factors involved . The authors suggest that thoughtful breeding of less aggressive individuals could reduce the prevalence of aggressive behavior – a suggestion with which we wholeheartedly agree . That said , nothing in this study actually supports that idea – though other research ( such as the Russian Fox Experiment we discussed in a previous issue ) does give it some credence . They also suggest that choosing the right dogs for one ’ s lifestyle and having multiple dogs may reduce rates of aggressive behavior . Finally , they point out that getting regular vet checks for older dogs could help reduce pain-related aggression . We hope you are already helping your clients with that last idea .
What can we take away from this study ? As always , since this research used a questionnaire , we must be careful about making assumptions regarding causality . All this research provides is information about what factors are associated with increased rates of aggression towards people , not what factors might be playing a part in causing that aggression . That means steps such as having multiple dogs may decrease the
The APDT Chronicle of the Dog | Winter 2021 37