Dog Bites: A Multidisciplinary Perspective

Daniel Mills, Carri Westgarth

• Publisher: 5m Books
• Year: 2017
• ISBN:
  9781912178483
• Topic: Medicine
• Subtopic: Veterinary Medicine

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. Experts who have researched into the many facets involved in the subject have not so far pooled their knowledge together. Dog Bites aims to bring together expert knowledge of the current situation from a wide variety of disciplines to provide information to the many people and professions affected by the issue. Subjects range from the practical, medical, behavioural, sociological and theoretical, but the overall approach of the book is to be 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, risk to children and a consideration of why some dogs kill. All contributors are academic or long-standing professional experts in their field and represent a wide spread of international expertise. The issue is an important one for pet owners, vets, animal shelters, and anyone who works with dogs, such as the police. This book is a valuable resource for them as well as for animal behaviourists, academic researchers, health professionals, dog breeders and handlers. Please be advised that this book contains strong images of the subject matter that some readers may find distressing.

Section 1
Fundamental Principles

In Section 1 we lay a foundation for what follows by considering some fundamental principles that should shape the way we think about the issues involved. In order to understand dog bites we need to be clear about what we know about the issue and how we know it. This might seem obvious, but when trying to understand the quality of our knowledge there is a big difference between personal opinions and beliefs (no matter how strongly held) and empirical information. As highlighted in this section, being clear on these matters is a major challenge to the study of dog bites. In order to study something, we need to be able to define it consistently, but in Chapter 1, Daniel Mills highlights the lack of consensus when we refer to aggressive behaviour and even bites in dogs. Perhaps if we can build a more consistent framework, as suggested in this chapter, we will make better progress.

In Chapter 2, Helen Zulch highlights how little we know about the meaning of signals produced by dogs and how much is based on opinion. The point is well made that if we can become more consistent in separating our descriptions of behaviour from our interpretations of it, then communications between those studying aggressive signals will be improved and we will recognise more clearly those areas where academic discussion and development should flourish in pursuit of knowledge.

In Chapter 3, Kenton Morgan and colleagues present a refreshing and incisive view of the use and abuse of statistics in relation to dog bites. This is not about hard numbers or difficult statistical concepts, but rather it is about understanding uncertainty. It is essential to understand these principles if we are not to be taken in by those who may knowingly or unknowingly misrepresent dog bite statistics and the associated risks.

Finally in Chapter 4, Francine Watkins and Carri Westgarth highlight the value of learning from a public health theoretical perspective when considering the issue of dog bites. Public health is well versed in dealing with the impact on human health of the complex interactions that exist between people and both their physical and social environments, and so provides an excellent framework for integrating all the information related to understanding why dogs bite. The chapters in this section not only highlight how complex the issue of dog bites is and how little we know, but also, and most importantly, provide a framework for making progress so we do not repeat the errors of the past.

Chapter 1

Dog Bites and Aggressive Behaviour – Key Underpinning Principles for their Scientific Study

Daniel Mills

1.1 Problems with the study of dog aggression

Major challenges to the interdisciplinary study of dog bites include recognising the diverse academic disciplines that can contribute to our understanding of the subject but also, and perhaps more fundamentally, actually defining the key terms and concepts of interest. Dogs bite for many reasons; for example they may nip with their incisors as an enticement to play (Horowitz, 2009) or bite with their canines to protect a resource (Wright, 1991) or in self-defence (Wright, 1991); other bites might be purely accidental encounters, for example when getting in the way of the dog lunging at another target. Superficially the end product is a bite in all of these circumstances, but this is of very limited (if any) value on its own, since we generally want to understand either why the bite occurred or what should be done about it to prevent future bites.

1.1.1 What is aggression?

To do this we need to understand the biology of bites and associated processes, including the concept of aggression and the difference between an incident and a problem situation.

For example, we ask two questions to the same population of individuals:

• Has your dog ever bitten another individual?
• Is your dog aggressive?

We can expect a very different prevalence of ‘yes’ responses. Terms such as ‘aggression’ and many others associated with dog bites are value laden terms, with no consistent objective definition. Indeed, this problem is not unique to dogs and has been recognised for a long time in the human literature, with van Der Dennen (1980) identifying more than 100 definitions of aggression in the academic literature relating to human behaviour. Few studies of dog aggression appear to have recognised this problem, with the concept often poorly or subjectively defined, or not defined at all (e.g. see Polo et al., 2015). This leads to enormous variation in the prevalence of aggression according to the criteria used to define it. All of the following problems may be perceived as aggressive behaviour by owners and so present as aggression within the reporting of case series (e.g. Denenberg et al., 2005). This is illustrated by the findings of Mills and Mills (2003), who gathered descriptive data on the behaviour of 722 UK pet dogs within 502 families. It was found that 547 dogs (75.8%) from 399 households were reported to bark when visitors arrived, 339 dogs (46.9%) from 242 households were reported to bark at other dogs, 113 dogs (15.6%) from ninety-one households were reported to chase livestock, fifty-one dogs from forty-eight households chased cars, seventy-seven dogs from seventy households chased bicycles, sixty-eight dogs from seventy-eight households chased joggers, 411 dogs from 334 households chased cats, 216 dogs from 184 households chased dogs and 216 dogs from 213 households chased other items. Rabbits and hares were the most common of these (eighty-one) followed by wild birds (seventy-four), squirrels (sixty) with fewer than twenty reports of other items. Some 66% of dogs tended to chase two or more classes of objects. All of these are potential contexts in which a dog’s response might be construed as aggressive, depending on how the term is defined or interpreted, but clearly this is not always the case; some dogs bark because they are alerting their owners to the presence of a visitor and some chase as a form of play with no intention of catching the target. The prevalence will clearly vary according to the definitions chosen, and also whether reporting and the owner or household level, and if comparisons are to be made between studies, e.g. to assess risk factors, then it must not be assumed that the term aggression is being used in the same way by different authors.

If we limit the definition of aggression to more direct signs of threat such as growling, snapping and biting, we obtain a very different picture. Forty-five (6.2%) showed one of these behaviours at least sometimes towards adult male household members, twenty-two (3.0%) towards male children in the household, thirty-one (4.3%) towards adult female household members, eighteen (2.5%) towards female children in the household, forty-eight (6.6%) towards familiar male adult visitors, twenty-five (3.5%) towards familiar male child visitors, forty-one (5.7%) towards familiar female adult visitors, thirty towards familiar female child visitors, 233 (32.3%) towards unknown male adult visitors, 106 (14.7%) towards unknown male child visitors, 191 (26.4%) towards unknown adult female visitors and 108 (15.0%) towards unknown female child visitors.

Overall, 48% showed growling, snapping or biting in three or more of the preceding contexts. One hundred and seventy-one (23.7%) dogs were said to growl to keep possession. Seventy-five (10.4%) would snap, bite or growl to protect their food bowl. One hundred and twenty (16.6%) growled and seventy-four (10.2%) snapped or bit to obstruct people from doing things; Seventy-eight (10.8%) would growl to stop people going somewhere and twenty-eight (3.9%) snap or bite at this time. Ninety-three (12.9%) dogs had attempted to or succeeded in biting an adult male, forty-six (6.4%) a male child, fifty-seven (7.9%) a female adult, forty (5.5%) a female child and 201 (27.8%) another dog, of whom eighty-seven of the targets were known to be male and sixty-six female. Seventy-nine incidents involving other animals were also reported, twenty-seven on cats, twenty on livestock, eighteen on wild mammals, nine on horses and the remaining on wild birds and other pets.

However, when asked to evaluate their dog’s behaviour, 260 (51.8%) owners reported their dog had an annoying habit (primarily related to vocalisation or obedience problems, rarely including aggressive behaviour) and only 127 (25.3%) owners described their dog as having a behaviour problem. When asked to describe the problem, the most common response related to growling, snapping and biting or predation, with forty-eight (9.6%) recorded, but there was no obvious association between the context of the dog’s growling, snapping and biting or its frequency and the likelihood that the dog would be described as having a problem in this regard. More recently, Westgarth and Watkins (2015) have even found disagreement over the perception of what a dog bite is, even though this might be thought to be more obviously definable on the basis of physical measures. The perception of participants as to whether a ‘real’ dog bite had occurred varied depending on whether or not the victim thought a dog ‘intended’ to bite for some. For others a bite received in play was a bite. Subjects also varied as to the need or nature of any skin damage, for some felt skin must be marked or broken for a bite to have occurred. Even within a single interview, a participant may contradict him or herself on such matters (Westgarth and Watkins, 2015). Clearly, there is little consistency in both an individual’s perception of aggression and its component features, and this applies to those reporting on such events as well as victims. A clear definition of aggression is an essential prerequisite to any study, so the reader has a clearer idea of what is being reported on and is not left to his or her own ideas.

Nonetheless, one conclusion from this work is that incidents that might be described as aggressive are probably very common and perhaps a normal part of having a dog, and even bites may be far more common than is generally reported since most may not inflict serious injury. A second conclusion is that the prevalence of such behaviour will vary enormously depending on how it is defined, and if it is not clearly defined it is not really possible to compare different reports, since they may not be describing the same phenomenon. Thirdly, there is no clear consensus of the features of aggressive behaviour that lead to it being defined as ‘problematic’. Certainly, owners do not appear to consider much of this behaviour problematic and, as reported in Chapter 23, perhaps victims might not either in some circumstances, although in others it might be more traumatic.

1.1.2 Is aggression a problem?

While this apparent lack of concern might be a cause for alarm, it perhaps also reflects a point that can easily be overlooked when a serious bite incident occurs, and receives significant media attention. People live with dogs and so have a lot of contact with them; there is an intrinsic risk associated with this, but serious injuries are not the norm, although these are the ones that attract the most attention and study. It is not logical to assume that non-injurious or minor dog bites reflect the fortunate avoidance of a more serious injury. To suggest this is to ignore the communicative function of most bites (see Chapter 2 and below). In many incidences it would be expected that a dog does not bite unless it has to, and it only inflicts the minimum damage necessary for it to convey its message. In support of this, we recently reported (Barcelos et al., 2015) that the bite incidents of dogs referred for being aggressive to the behaviour clinic at University of Lincoln had a number of commonalities when the dog was found to have a focus of musculoskeletal pain that had gone either unnoticed or unrecognised. Bites tended to be located on the extremities of the target, with incidents being of relatively short duration and easy to interupt, i.e they were brief incidents aimed at inflicting minimal damage in order to avoid further interaction. These features were not recurring themes in cases referred for similar reasons but without an identifiable pain focus, where the reasons for the behaviour were more variable, e.g. to control a valued resource.

As discussed elsewhere, if we really wish to manage the risk of significant harm, we need to also study the wider communicative context preceding dog bites. On the other hand, it is unwise to assume that dog bites, even serious ones, are always the prelude to a fatality. The latter are fortunately extremely rare (it has been reported that a child in the USA stands a greater chance of drowning in a 5 gallon bucket of water than dying from a dog bite (Bradley, 2014), even though they are exposed to dogs much more than buckets of water) and fatalities may have unique circumstances that require special consideration (e.g. see Chapter 11 and Patronek et al., 2013).

Good data are an essential prerequisite for good science and the usefulness of knowledge that we gain as a result. To get good data, we need to clearly distinguish what we observe from how we interpret it, and a failure to do this seems to be a recurring problem in this field. Chapter 2, describes the state of the art with regards to how we might interpret the aggressive behaviour of dogs, while this chapter focuses on the underlying principles and presents a framework for making inferences about the underlying motivation and emotion of a dog involved in an aggressive incident in a field rather than laboratory setting.

1.2 Aggression versus aggressive behaviour

1.2.1 The definition of aggression

The etymology of the noun ‘aggression’ stems from the Latin...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Dedication
• Acknowledgements
• Contributors
• Introduction
• Section 1 Fundamental Principles
• Section 2 Perceptions of Dogs that Bite
• Section 3 Dog Bites and Risk
• Section 4 Investigative and Legal Issues
• Section 5 Health Issues
• Section 6 Handling the Aggressive Dog
• Section 7 Managing Future Risk
• Section 8 Prevention
• Section 9 Concluding Comments
• Afterword
• Index