Tag Archives: aggression

Dogs’ ag­gress­ive be­ha­viour to­wards humans is of­ten caused by fear

A study encompassing some 9,000 dogs conducted at the University of Helsinki demonstrated that fearfulness, age, breed, the company of other members of the same species and the owner’s previous experience of dogs were associated with aggressive behaviour towards humans. The findings can potentially provide tools for understanding and preventing aggressive behaviour.

Photo by Shutterstock

Aggressive behaviour in dogs can include growling, barking, snapping and biting. These gestures are part of normal canine communication, and they also occur in non-aggressive situations, such as during play. However, aggressive behaviour can be excessive, making the dog a health threat to both humans and other animals.

“Understanding the factors underlying aggressive behaviour is important. In what kinds of circumstances does aggressive behaviour occur and what is the dog’s motive for such behaviour? In normal family dogs, aggressive behaviour is often unwanted, while some dogs with official duties are expected to have the capacity for aggressiveness. At the same time, aggressiveness can be caused by welfare issues, such as chronic pain,” says doctoral researcher Salla Mikkola from the University of Helsinki.

The canine gene research group active at the University of Helsinki surveyed connections between aggressive behaviour and several potential risk factors with the help of a dataset encompassing more than 9,000 dogs, a sample from a larger dataset from a behavioural survey dataset of nearly 14,000 dogs. The study investigated aggressiveness towards both dog owners and unfamiliar human beings. Dogs were classified as aggressive if they growled often and/or had attempted to snap at or bite a human at least occasionally in the situations described in the survey.

“Dogs’ fearfulness had a strong link to aggressive behaviour, with fearful dogs many times more likely to behave aggressively. Moreover, older dogs were more likely to behave aggressively than younger ones. One of the potential reasons behind this can be pain caused by a disease. Impairment of the senses can contribute to making it more difficult to notice people approaching, and dogs’ responses to sudden situations can be aggressive,” Mikkola adds.

Small dogs are more likely to behave aggressively than mid-sized and large dogs, but their aggressive behaviour is not necessarily considered as threatening as that of large dogs. Consequently, their behaviour is not addressed. In addition, the study found that male dogs were more aggressive than females. However, sterilisation had no effect on aggressive behaviour.

The first dogs of dog owners were more likely to behave aggressively compared to dogs whose owners had previous experience of dogs. The study also indicated that dogs that spend time in the company of other dogs behave less aggressively than dogs that live without other dogs in the household. While this phenomenon has been observed in prior research, the causality remains unclear.

“In the case of dogs prone to aggressive behaviour in the first instance, owners may not necessarily wish to take a risk of conflicts with another dog,” Mikkola muses.

Sig­ni­fic­ant dif­fer­en­ces in ag­gress­ive be­ha­viour between breeds

Differences in the aggressiveness of various dog breeds can point to a genetic cause.

“In our dataset, the Long-Haired Collie, Poodle (Toy, Miniature and Medium) and Miniature Schnauzer were the most aggressive breeds. Previous studies have shown fearfulness in Long-Haired Collies, while the other two breeds have been found to express aggressive behaviour towards unfamiliar people. As expected, the popular breeds of Labrador Retriever and Golden Retriever were at the other extreme. People who are considering getting a dog should familiarise themselves with the background and needs of the breed. As for breeders, they should also pay attention to the character of dam candidates, since both fearfulness and aggressive behaviour are inherited,” says Professor Hannes Lohi from the University of Helsinki.

This study is part of a wider Academy of Finland project that investigates the epidemiology of canine behaviour, as well as related environmental and genetic factors and metabolic changes. Professor Hannes Lohi’s research group conducts research at the Faculties of Veterinary Medicine and Medicine, University of Helsinki, as well as the Folkhälsan Research Center. This study was supported, among others, by the Academy of Finland (308887), the European Research Council (Starting Grant), the ERA-NET NEURON funding platform and the Jane and Aatos Erkko Foundation.

Ori­ginal art­icle:

Salla Mikkola, Milla Salonen, Jenni Puurunen, Emma Hakanen, Sini Sulkama, César Araujo, Hannes Lohi. Aggressive behaviour is affected by demographic, environmental and behavioural factors in purebred dogs. Scientific Reports. doi.org/10.1038/s41598-021-88793-5

Source: University of Helsinki

Climbing the social ladder is ruff business says new research

Top dogs in a pack are known to assert their dominance, but scientists studied a group of free-roaming mongrels and found high levels of aggression in the middle of the dominance hierarchy.

Most theories predict more aggression higher up the ladder. However, the researchers say the difficulty of working out the pecking order in the crowded middle leads to aggression.

Wild_dogs

The study focussed on a group of wild dogs living on the outskirts of Rome (credit: Simona Cafazzo)

The research was carried out by the University of Exeter (UK) and by the Veterinary Service of the Local Health Unit Rome 3 (Italy).

“Our results reveal the unavoidable costs of climbing a dominance hierarchy,” said Dr Matthew Silk, of the Environment and Sustainability Institute on the University of Exeter’s Penryn Campus in Cornwall.

“In the middle of the hierarchy – where it’s harder to predict which animal should be dominant – we see lots of aggression.”

Professor Robbie McDonald said: “Fighting over food and mates uses energy and time and can lead to injuries, so hierarchies play an important role because animals know their place without needing to fight.”

The year-long study examined a pack of 27 mongrel dogs that roamed freely in the suburbs of Rome.

The dogs did not live with humans, although they relied on humans for food.

Their hierarchy was based on age and sex, with adults dominant over younger dogs and males dominant over females of the same age group.

“Although fights within a social group of free-roaming dogs are usually characterised by low-intensity aggression, the middle of the hierarchy is occupied by young males of similar size and age, among whom nothing is definitive and for whom the challenge is to gain rank,” said Dr Simona Cafazzo, of the University of Veterinary Medicine, Vienna.

“Our results confirm that these dogs have an age-graded dominance hierarchy similar to that of wolves,” added Dr Eugenia Natoli, of the Veterinary Service of the Local Health Unit Rome 3.

Dominant behaviour included a stiff, upright body, holding the head and tail high and laying a paw on another dog’s back.

Submissive behaviour included avoiding eye contact, holding the head and ears low and lying down with the chest and stomach exposed.

The research was partly funded by the Natural Environment Research Council.

The paper, published in the journal Proceedings of the Royal Society B, is entitled: “Elevated aggression is associated with uncertainty in a network of dog dominance interactions.”

Source:   University of Exeter

Dog Bites: A Multidisciplinary Perspective

There’s a new book out about the subject of dog bites, taking a multidisciplinary perspective.  I haven’t read it yet – but is positive to see a publication incorporating different views on the issue – all in one place.

Dog Bites is organized into nine sections titled Fundamental Principles, Perceptions of Dogs that Bite, Dog Bites and Risk, Investigative and Legal Issues, Health Issues, Handling the Aggressive Dog, Managing Future Risk, Prevention, and Concluding Comments.

Dog Bites A Multidisciplinary Perspective

The book’s description says:

The issue of dog bites and dog aggression directed at humans is frequently in the media. However, scientific research and evidence on the subject is scattered and sparse. Public and political opinions are often misinformed and out of proportion to the extent of the problem. Dog Bites brings together expert knowledge of the current situation, from a wide variety of disciplines, to provide information to the many people and professions affected by this issue. Subjects range from the practical, medical, behavioural, sociological, and theoretical, but the overall approach of the book is objective and integrative. Topics addressed include: the genetic basis of aggression; the public image of aggressive dogs; bite statistics; risk factors; the forensics and surgical aspects of dog bites; international legal perspectives; court evidence; first aid treatment; zoonotic disease potential; behavioural rehabilitation options; the risk to children; and a consideration of why some dogs kill. All contributors are academic or long-standing professional experts in their field, and they represent a wide spread of international expertise. This issue is an important one for pet owners, vets, animal shelters, and anyone who works with dogs, such as the police. This book will be a valuable resource for them, as well as for animal behaviourists, academic researchers, health professionals, dog breeders, and handlers.

I’m adding this one to my reading list!

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, The Balanced Dog, Christchurch, New Zealand

Hear bark or C-Barq?

I’ve just signed Izzy up so we can complete a C-Barq questionnaire for her.

I know what you are thinking:  you don’t ‘see’ barks, you hear them.  Well actually, C-Barq stands for ‘Canine Behavioral Assessment and Research Questionnaire’ and it’s another example of citizen – or participatory – science.

Created by Dr. James Serpell who is a behaviorist at the Center for the Interaction of Animals and Society (CIAS) in Pennsylvania, the questionnaire is designed to provide dog owners and professionals with standardized evaluations of temperament and behavior.    The Center is based within the School of Veterinary Medicine at the University of Pennsylvania.

Penn University medicine

Tested extensively for reliability and validity on large samples of dogs of many breeds,  the current version consists of 101 questions describing the different ways in which dogs typically respond to common events, situations, and stimuli in their environment. It should take about 15 minutes to complete (I haven’t done this yet).

Please pay attention, however, to the sign-in page where questions are asked about your dog’s breed, background, and behavior.  This helps in coding the answers for analysis.

So far, over 80,000 dogs have been included in the study. Dr Serpell says, “There is no other breed or species of animal with such a wide variety of appearance and behavior.”

Between 10 percent and 15 percent of dogs can show very high levels of aggression, Serpell says, while 20 or 30 percent show no aggression.

Pit bulls and Akitas, popular breeds for fighting and guard dog duty, show serious aggression toward other dogs. But the title for most aggressive overall actually goes to tiny dachshunds, which display heightened aggression toward dogs, strangers and even their owners.

Source:  Science Friday on pri.org

Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, Canine Catering Ltd, Christchurch, New Zealand

Behavioural problems in pet store dogs

Dogs purchased from pet stores are more likely to have a range of behavior problems than those purchased from small, non-commercial breeders, says a study by researchers at the Best Friends Animal Society and the University of Pennsylvania School of Veterinary Medicine.

The study was published in the Journal of the American Veterinary Medical Association.

The study involved 413 dogs purchased from pet stores.  Psychological and behavioral characteristics of these dogs were compared to the same characteristics in 5,657 dogs obtained from small-scale, private breeders.  (Most puppies sold in pet stores in the USA are sourced from large-scale, puppy mill type commercial breeders).

Results show that dogs obtained as puppies from pet stores showed significantly more aggression toward human family members, unfamiliar people and other dogs. Dogs purchased from pet stores were almost twice as likely to exhibit aggression directed toward unfamiliar dogs than dogs purchased from small non-commercial breeders.

The pet store dogs also a displayed greater fear of other dogs and typical events in pet dogs’ lives, had more behavior problems when left alone at home, and experienced more problems with house-soiling.  These behaviors in young adult dogs are reasons typically cited by people who surrender their pets to animal shelters.

“The results were so one-sided that in the wide range of behavior problems we included in our analysis, pet store dogs failed in every single case to even obtain one more favorable score than the comparison group of dogs” says Dr Frank McMillan of Best Friends Animal Society.

The research team acknowledges that the exact causes of the behavioral problems observed are not known; until these causes are understood, they recommend avoiding purchasing puppies from pet stores.

Source:  BusinessWire media release

See my related post about the ASPCA’s No Pet Store Puppies initiative

 

 

 

No correlation between breed and aggression

Researchers from the University of Bristol’s School of Veterinary Sciences have investigated the occurrence of dog aggression towards people with a survey of UK dog owners.

The 4,000 responses revealed:

  • aggression towards unfamiliar people was reported more commonly by owners than aggression to family members
  • 7 per cent of owners responded that their dog barked, lunged, growled or actually bit when people came to the house
  • 5 per cent of owners said that these things happened when out on walks
  • 3 per cent of owners reported aggression towards family members

Dog bearing teeth

The study highlighted that the majority of dogs showing aggression do so in just one type of situation. This indicates that the tendency to categorise dogs as either generally ‘safe’ or ‘vicious’ is a misconception, and that most dogs show aggression as a learnt response to particular situations.  (A lot of trainers working in animal shelters probably already knew this.)

The research also highlighted that although general characteristics, such as breed type, are significant risk factors across large populations they explain only a small amount of the overall difference between aggressive and non-aggressive dogs.   Therefore, it is not appropriate to evaluate the risk of aggressive behaviour in an individual dog using characteristics such as breed type.

That’s another black mark for supporters of breed specific legislation!

The results of this research have been published in the journal of Applied Animal Behaviour Science.

Source:  University of Bristol media release

Fences for Fido

The animal welfare sector is comprised of many volunteer organisations.  One special one working in the Oregon and Washington area is Fences for Fido.

This volunteer effort has been working since 2009 to build fences for dogs so they can be released from their chains.  Chained dogs rarely have the quality of life of other pets and are vulnerable to aggression from other dogs who are able to roam into their territory and take advantage of the dog’s restrictions.  Studies show that dogs who are chained can respond in one of two ways:  they become aggressive or they become withdrawn and unresponsive.

More importantly, dogs who are chained are unlikely to have the same bonds and stable relationship with their owners/family.  Many are isolated and live a lonely existence and suffer from neglect.

Without prejudice, Fences for Fido assists these dog owners by building fenced sections on weekends.  Materials and time are all donated and there is also support for neutering/spaying and veterinary care when needed.   The group works to educate families about dog care during the extreme seasons of summer and winter.

This group also follows up with families that have received its assistance twice each year to ensure that the dogs remain unchained and in good condition.

Almost 300 dogs have been helped by Fences for Fido so far.

That’s a special group!

Here’s a video of their first-ever fence building project – for Chopper – in 2009:

The importance of pain management

Whenever I take on a new client, I use a health questionnaire that covers current conditions as well as the dog’s health history.  One of the issues I address is any recent changes to the dog’s behaviour or living conditions.

What I am trying to ascertain is if a dog is in pain or having adjustment difficulties. There is a clear link between pain and aggression and this has been supported in a recent study by researchers at the Autonomous University of Barcelona in Spain.

In the Spanish study, which has been published in the Journal of Veterinary Behavior, 12 dogs that were brought in by their owners for ‘aggression problems’ were studied.  All were found to have pain-induced aggression with eight diagnosed as having hip dysplasia.

The breeds in the study were:  a Giant Schnauzer, Irish Setter, Pit Bull, Dalmatian, two German shepherds, Neapolitan Mastiff, Shih-tzu, Bobtail, Catalan Sheepdog, Chow Chow and Doberman.

The researchers concluded “if the pet is handled when in pain, it will quickly act aggressively to avoid more discomfort without the owner being able to prevent it.”

So, when a dog is behaving differently or is “out-of-sorts”, a visit to the vet is recommended.  Behaviour changes can be the first indicator that something is wrong and your vet can help to run appropriate tests to see if there is an underlying health problem.

Dogs have a way of not telling us they are in pain until a problem is more pronounced because their natural instinct is to protect themselves by not exhibiting any noticeable vulnerabilities.  Therapies such as massage and low level laser (which I employ in my canine rehabilitation practice) are useful in helping to manage pain through appropriate stimulation of acupressure points and managing muscle, tendon and ligament condition.  I’m also a strong supporter of acupuncture and refer clients to a local vet who is trained in veterinary acupuncture.

These complementary therapies can be employed alongside traditional pain medications such as NSAIDs to support your dog’s quality of life.  When pain is managed, quality of life improves for everyone in the household.

Source:  Plataforma SINC. “If your dog is aggressive, maybe it is in pain.” ScienceDaily, 13 Jun. 2012. Web. 15 Jun. 2012.