Tagged: Dog

Aggressive behaviour in dogs: a survey of UK dog owners

Aggressive dogs represent a serious risk to human health, tragically causing fatalities in some cases. The development of aggression can also impact on the welfare of dogs themselves, often resulting in the break-down of the human-pet bond, euthanasia or relinquishment. Research into factors which influence the development of aggression is therefore very important. One type of research commonly used is epidemiology. This type of study looks at populations of dogs with the aim of identifying common factors which might help explain the development of aggression. A number of approaches have been used in epidemiological research, varying both in the types of population studied and the factors measured. These different approaches add to the understanding of the problem and give us valuable new insights. For example, a number of studies have investigated the occurrence of dog bites by looking at information on hospital admissions1,2. Interesting recent research has also looked at potentially preventable husbandry factors in a series of fatal dog bite cases in the USA3 (nicely summarised and discussed in these blogs4,5). This type of study is crucial in informing us about the specific circumstances in which the most serious aggressive incidences occur.

Other populations of dogs that have been studied include cases referred to specialist behaviour clinics6,7 or dogs relinquished to shelters8. These studies highlight the impact on dog owners, with aggression being the most common reason for people to seek specialist help, and an important reason for abandonment. The great value of these types of study is that they can include a detailed evaluation of the specific circumstances or contexts in which aggression occurs.

A further epidemiological approach is to use more general populations, such as owners visiting first opinion veterinary practices8, or surveys of dog owners in the general population9,10. These populations provide information about factors which may be important across a broader range of dogs or dog owners. We took this approach in two recently published papers investigating aggression in UK dogs. Our interest was to examine potential risk factors for dogs showing any aggression either to other dogs11 or people12. Dog owners were asked to fill in a questionnaire about one of their dogs. We asked them whether their dog barked, lunged, growled or bit in a number of situations. These were: when meeting other dogs when out for walks; with other dogs within a household; when meeting unfamiliar people when out of the house; when meeting unfamiliar people entering the house, or when with family members. We were interested in how common it was for aggression to occur in these different situations, and whether the same dogs showed aggression in multiple situations. We also went on to look at potential risk factors for aggression by comparing the characteristics of dogs which showed aggression with those which did not – and I’ll come back to that part in a later blog post.

Cross breed dog growling towards the camera

How common is aggression in UK dogs?

Questionnaires were distributed to just under 15,000 dog owners in a range of different situations: veterinary practices, dog shows or similar events, agricultural or horse shows, directly to dog walkers, pet stores, and a range of other locations. Just under 4000 questionnaires were returned to us completed (thank you so much lovely dog owners!), and these gave us an idea of the proportion of dogs showing aggression. The most common context in which aggression occurred was towards other dogs on walks (22% of respondents)11, and the least common was aggression to family members (3%)12 – numbers and percentages for all the situations we investigated are shown in the table below.

Situation in which aggression occurred



Towards family members12



Towards unfamiliar people entering the house12



Towards unfamiliar people when outside the house12



Towards other dogs when out on walks11



Towards other dogs in the household11



Although we distributed questionnaires as widely as possible, it is important to interpret these numbers with a bit of caution, because the owners who participated were not necessarily representative of the total UK dog population. For example, those not registered with a vet or who lived in remote areas were unlikely to have seen the survey. However, these numbers give us an idea about the relative prevalence of different types of aggression – and particularly highlight that aggression between dogs is a worryingly common problem, something that those working in dog behaviour are probably well aware.

Do individual dogs show aggression in multiple situations?

There is a common perception that aggression is a fixed characteristic of particular dogs – people often think that dogs are either ‘safe family dogs’ or ‘nasty / vicious dogs’ based on traits inherent to the breed or the dog itself. However, our studies highlighted that dogs were rarely aggressive in more than one situation: co-occurrence of aggression between contexts was remarkably low. This tends to suggest that dogs learn to show aggression in particular situations through learning. Hence, whilst some characteristics of personality may be important in the development of aggression, the unique learning experiences of each individual dog is also likely to be very important.

This has two important implications: dog owners and members of the public need to be aware that any dog could potentially show aggression, even where it has never done so in other situations. Secondly, dogs which have shown aggression in one situation are not necessarily ‘dangerous’ when in other contexts – an important factor in the assessment of animals, for example in re-homing centres.


  1. De Keuster, T., Lamoureux, J., Kahn, A., 2006. Epidemiology of dog bites: a Belgian experience of canine behaviour and public health concerns. Vet. J. 172, 482-487.
  2. Morgan, M., Palmer, J., 2007. Dog bites. Br. Med. J. 334, 413-417.
  3. Patronek, G.J., Sacks, J.J., Delise, K.M., Cleary, D.V. and Marder, A.R. (2013). Co-occurrence of potentially preventable factors in 256 dog bite-related fatalities in the United States (2000-2009). J Am Vet Med Assoc. 2013 Dec 15; 243(12):1726-36. doi: 10.2460/javma.243.12.1726.
  4. National Canine Research Council (2013). Potentially Preventable Husbandry Factors Co-occur in Most Dog Bite-Related Fatalities
  5. Cattet, J. (2013) New study sheds light on serious to fatal dog bites
  6. Bamberger, M., Houpt, K.A. (2006). Signalment factors, comorbidity, and trends in behavior diagnoses in dogs: 1,644 cases (1991-2001). J. Am. Vet. Med. Assoc. 229, 1591-1601.
  7. Fatjo, J., Amat, M., Mariotti, V.M., de la Torre, J.L.R., Manteca, X., 2007. Analysis of 1040 cases of canine aggression in a referral practice in Spain. Journal of Veterinary Behavior-Clinical Applications and Research 2, 158-165
  8. Guy, N.C., Luescher, U.A., Dohoo, S.E., Spangler, E., Miller, J.B., Dohoo, I.R., Bate, L.A., 2001. Risk factors for dog bites to owners in a general veterinary caseload. Appl. Anim. Behav. Sci. 74, 29-42
  9. O’Sullivan, E.N., Jones, B.R., O’Sullivan, K., Hanlon, A.J., 2008. The management and behavioural history of 100 dogs reported for biting a person. Appl. Anim. Behav. Sci. 114, 149-158.
  10. Hsu, Y., Sun, L., 2010. Factors associated with aggressive responses in pet dogs. Appl. Anim. Behav. Sci. 123, 108-123.
  11. Casey, R.A., Loftus, B., Bolster, C., Richards, G.J. and Blackwell, E.J. (2012). Inter-dog aggression in a UK owner survey: prevalence, co-occurrence in different contexts and risk factors. doi: 10.1136/vr.100997
  12. Casey, R.A., Loftus, B., Bolster, C., Richards, G.J. and Blackwell, E.J. (2013). Human directed aggression in domestic dogs (Canis familiaris): occurrence in different contexts and risk factors. doi: http://dx.doi.org/10.1016/j.applanim.2013.12.003

Should fearful dogs be comforted on fireworks night?

There is lots of good advice around about how to cope with dogs that are frightened of fireworks. However, one common element seems to be “ignore your dog if he is showing signs of fear during fireworks night, or you will REINFORCE HIS FEAR”. Words to this effect appear all over the place. But this statement doesn’t make sense from a scientific perspective, and potentially creates problems from a dog welfare one. In this blog, I explain why.

Attention does not reinforce the fear response

Lots of dogs become frightened of fireworks – our research has suggested that almost half of owners report behavioural signs indicative of anxiety or fear to loud noises, and 82% of these react to fireworks1,2. Fireworks are very loud, very bright and completely unpredictable for dogs – so it is unsurprising that so many develop a fear response. In trying to find a behavioural strategy to cope with the fear induced by the noises, dogs will try a range of different behaviours3. These might include hiding behind the sofa, running about, or climbing in a cupboard. Many dogs react by going to their owner and seeking reassurance. They do this because the social contact with their owner reduces their stress and helps them to cope with the scary noises. Social contact therefore helps mitigate their fear response to the noises – not reinforce it.

Owner giving their anxous dog a cuddle

Attention reinforces a coping strategy

Although giving attention will reduce a dog’s anxiety in the short-term, it is not necessarily a good thing in the long-term. Cuddling a fearful dog reduces their stress, but in doing so teaches him or her that coming to their owner is a good strategy to cope with loud noises. In other words, giving attention doesn’t reinforce the fear, but does reinforce the coping strategy of seeking attention. This is fine as long as the owner is at home and accessible – but will make things much worse for the dog if the owner is out when loud noises subsequently occur. This means that by reinforcing attention seeking as a way of coping with loud noises, owners are setting up their dog to be even more distressed if noises happen when their dog is alone.

So to cuddle or not cuddle on fireworks night?

Well, with fireworks night imminent in the UK – it is very important to not ignore a frightened dog that is already reliant on owner attention. It is the wrong time to try to change a coping strategy when there are fireworks crashing and whizzing outside – this will just cause the dog to be distressed. Owners need to give dogs which seek reassurance as much attention as normal FOR NOW, get through the fireworks season, and THEN think about changing their dog’s coping response.

Dogs which choose to move away and hide, on the other hand, should be left alone – their strategy to cope with noises is different and they may become more anxious, or even aggressive, if approached when trying to hide.

Other aspects of owner behaviour

Dogs are very sensitive to their owners, so acting differently from normal can increase anxiety. This means that dog behaviour can be influenced by owners reacting to fireworks. It is best for owners to try to do normal things at normal times. Jumping up and down checking for fireworks can direct dogs’ attention to what is going on outside. Where owners are overly concerned about their dog, this can also impact on their dogs’ anxiety.

Changes needed in the longer term

In the long-term, it is important to change a dogs’ coping behaviour away from seeking attention. Teaching dogs to hide in an enclosed ‘den’ area when they are worried ensures that they have coping strategy that doesn’t depend on the owner being present. Dogs also need to learn that firework noises are not scary, with a programme of desensitisation and counter-conditioning. More information about what to do for dogs with noise fears is available on my web-site4.

As ever, prevention of noise fears by habituating young puppies to household and potentially aversive sounds like fireworks is important to reduce this problem in the future5.


  1. Blackwell, E.J., Bradshaw, J.W.S. and Casey, R.A. (2013). Fear responses to noises in domestic dogs: Prevalence, risk factors and co-occurrence with other fear related behaviour. Applied Animal Behaviour Science, http://dx.doi.org/10.1016/j.applanim.2012.12.004
  2. Fear responses to noises (noise phobias) in dogs: http://vetbehaviour.info/dogs/noise-fears-in-dogs.html
  3. Signs and development of noise fears in dogs: http://vetbehaviour.info/dogs/20-noise-fears-in-dogs/17-signs-and-development-of-noise-fears-in-dogs.html
  4. What do I do if my dog is frightened of loud noises?: http://vetbehaviour.info/dogs/20-noise-fears-in-dogs/18-what-do-i-do-if-my-dog-is-frightened-of-loud-noises.html
  5. Habituation of puppies to household and potentially aversive noises (an except from the supporting materials for the Advisory Council on the Welfare Issues of Dog Breeding’s Breeder Standard): http://vetbehaviour.info/images/PDFs/Dog-Advisory-Council-Prevention-of-Noise-Fears.pdf

Dogs and fireworks: noise phobias or noise fears?

Fear responses to loud noises are common in the owned dog population, and a considerable welfare problem. Our research at the University of Bristol suggests that almost half of owners report some behavioural signs of fear in their dog in response to loud noises, although the owners interviewed didn’t always realize that these signs are indicative of a negative emotional state1,2

The behaviours shown are variable, ranging from trembling and shaking, barking and seeking comfort from owners1,3. In some cases, these signs can be extreme and impact on owners lives – in which case they may seek help from their veterinary surgeon or behaviour specialist. In many other cases, the behaviours are more subtle and less obvious to owners – but these dogs may be just as stressed3.

A picture of fireworks

The focus for ‘behaviour problems’ has traditionally been on those behaviours which cause a problem for people, rather than those situations which cause a problem for animals4. Literature addressing dogs’ responses to loud noises tends to focus on those cases in which dogs show the most obvious, active or extreme responses – and this is probably why the phrase ‘noise phobia’ e.g.5 is used to describe them. But is that really the best term to describe dogs’ fear responses to loud noises?

Why not ‘noise phobia’?

1. Firstly, phobias in human literature are defined as ‘irrational fears’.6 Fireworks are very loud, bright and startling things. They are also unpredictable –occurring suddenly and for no good doggy reason at all. So showing a fear response is pretty adaptive and ‘rational’. They are also largely uncontrollable: although many of the behavioural signs that dogs show in response to loud noises are attempts to control their exposure3, they are mostly ineffective in escaping the noises and achieving relief. These characteristics –salience, unpredictability and uncontrollability – are important factors influencing the likelihood of an increased response (sensitisation) rather than adaptation (habituation) to a stimulus. Is it therefore irrational for dogs to react to fireworks? Absolutely not, any more than fears after traumatic events are not ‘irrational’ in humans7 – and it shouldn’t be surprising that so many dogs react as they do.

2. The term ‘phobia’ suggests an extreme or long-lasting response. But not all animals that are fearful of noises show an obvious response – some may react with more subtle signs. Dogs’ responses to loud noises are variable in the same way that separation responses vary between individuals8. Just because a dog isn’t leaping about or tunnelling into cupboards doesn’t mean that he or she isn’t scared of loud noises, and it is important that terms describing these behaviours include the full range of signs.

3. ‘Phobia’ also suggests a response to a lower level of noise than would normally be adaptive. Dogs’ response to noises will vary with their individual characteristics, but also importantly with learning experiences. With repeated exposure, sensitisation leads to an animal responding to noises at a progressively lower threshold. Although a dog may start by reacting to a loud firework going off next door, this can develop over time into a response to a barely audible noise in the distance. Hence, cases which appear to be more serious (or ‘irrational’) and occur at low levels of noise have often just been developing for longer.

Does it matter what we call it?

I’m sure that my students would agree that I’m a bit of a pedant when it comes to terminology in behavioural medicine – but how we describe things impacts on perceived meaning. This is particularly important where terms have potential welfare implications (as with ‘dominance’), so care should be taken with descriptors and definitions.

Many owners don’t understand that an initial startle response to a firework going off next door can develop into an extreme ‘phobic’ response to a car door being slammed down the street, through the normal processes of learning. By using the term ‘phobia’, the focus is on the extreme, low threshold and apparently ‘irrational’ responses. However, the key message is to encourage owners to recognize the early signs of anxiety or fear in their dogs – and to seek help for these before the problem develops further. Owners need to understand that by recognizing and acting on subtle signs of anxiety in their dogs, treatment of noise fears is likely to be easier and more successful. And maybe it would help to do this if our terminology didn’t imply that only the most obvious presentations are a problem?


  1. Blackwell, E.J., Bradshaw, J.W.S. and Casey, R.A. (2013). Fear responses to noises in domestic dogs: Prevalence, risk factors and co-occurrence with other fear related behaviour. Applied Animal Behaviour Science, http://dx.doi.org/10.1016/j.applanim.2012.12.004
  2. Fear responses to noises (noise phobias) in dogs: http://vetbehaviour.info/dogs/noise-fears-in-dogs.html
  3. Signs and development of noise fears in dogs: http://vetbehaviour.info/dogs/20-noise-fears-in-dogs/17-signs-and-development-of-noise-fears-in-dogs.html
  4. Behaviour problems in dogs and cats: http://vetbehaviour.info/behaviour-problems.html
  5. Tuber, D.S., Hothersall, D. and Peters, M.F. (1982). Treatment of fears and phobias in dogs. Veterinary Clinics of North America: Small Animal Practice, 12, 607-623.
  6. Seligman, M.E. (1971). Phobias and preparedness. Behaviour Therapy, 2, 307-320.
  7. Davey, G.C.L. (1995). Preparedness and phobias – specific evolved associations or a generalized expectancy bias. Behavioral and Brain Science, 18, 289-297, http://dx.doi.org/10.1017/S0140525X00038498
  8. How puppies become anxious ‘home alone’ dogs: https://behaviourvet.wordpress.com/2013/10/26/how-puppies-become-anxious-home-alone-dogs/