Netherlands Study Also Examines Dog-on-Dog Attack Aggression
Two European studies examine dog-on-dog attacks and dog-killing aggression.
UK Study Abstract
United Kingdom - A study from the UK published in 2020 provides a glimpse into the prevalence and characteristics of dog-on-dog attacks in a public space. This study came three years after a UK survey (underwritten by a pet insurance company) estimated that 64,000 dogs are killed annually and over 44,000 suffered severe injuries due to dog-on-dog aggression. Roughly 15% of adult UK dog owners had seen their pet attacked by another dog during the 12 month period.1
The survey numbers are based on the estimated population of 8.66 million dogs in the UK. About 1.3% of the UK's dog population was affected. If applied to the US (77 million dogs),2 deaths and severe injuries due to dog-on-dog attacks would be over nine times higher. An estimated 1 million pet dogs in the US would be killed or severely injured by dogs each year. This shows a glaring absence of due diligence by humane groups, which claim to "protect" and "advocate" for dogs.
Dog Bites Dog: The Use of News Media Articles to Investigate Dog-on-Dog AggressionAbstract - Dog-on-dog aggression is a common behavioral problem and has the potential to result in dog and/or human injury, the need for veterinary treatment and financial and legal repercussions. Despite this, few studies of dog-on-dog aggression have occurred. News reports of dog-on-dog aggression provide a method of understanding the demographics of these attacks. National and local news articles between September 2016 and February 2020 were identified through Yahoo and Google news. Information was retrieved including victim/attacker dog information (age, breed, size, sex, injury, veterinary treatment, on/off a lead, with/without the owner/walker), situation, intervention, owner injury, and outcome. In the majority of these attacks, one dog initiated the attack and this dog tended to be a medium-sized breed and off-leash. The most reported attacking breed was the Staffordshire bull terrier. The victim tended to be a small-sized dog, and these attacks often had adverse psychological and physical effects. Costs as a result of the attack ranged from £75 to £9,000 (~ $98-11,800 USD). The owner intervened in just under half of cases and often suffered injuries defending their dog. (Montrose, 2020)
As you read through this post, consider the following themes. "Dog-on-dog aggression is a common behavioral problem," but "few studies of dog-on-dog aggression have occurred." Such studies are rare in the UK and are totally absent in the US. Each year, Animals 24-7 estimates these numbers, but those estimates could be low. At least they are a starting point, given that no regional or national humane or veterinary organization attempts to collect or quantify this data.
Most humane organizations and shelters not only ignore this problem, they exacerbate it by "continuously" adopting out dogs with dog-killing aggression using concealed language that the dog is "dog selective" (could kill some dogs), the dog "must be the only dog in home" (will kill a dog) or is "reactive toward other dogs" (could kill a dog), Remember "Floppy" at Austin Pets Alive? Floppy is dog-aggressive, has a low children score and is too dangerous to even be cat tested.
Questions to Bear in Mind
- Why is there a glaring absence of data -- peer-reviewed and otherwise -- about the most common type of dog attack, dog-on-dog attacks, in the US and UK?
- Did the absence of data in this purposefully neglected field of study lead the authors to examine the best and only available source of raw data -- news reports?
- Why is there a glaring absence of concern about dog-on-dog attacks in the US and UK by institutions and nonprofits that claim to "protect" and "advocate" for dogs?
- Is anyone surprised that bull breeds, selected for bull-baiting and dogfighting, topped the charts in the UK and Netherlands studies, and did so by a landslide?
- Humane groups have long attacked the use of news reports to track breeds of dogs that kill humans, yet here is a peer-reviewed study using this very source.
The UK study reviewed 151 news reports related to dog-on-dog attacks published between September 1, 2016 and February 29, 2020. The parameters captured included: article information (publication and date), theme of article, victim and attacking dog information (breed, size, sex, injury, veterinary treatment, on/off a lead, with/without the owner), situation (location and month of attack, context of attack), human intervention and injury, and canine and human outcome.
All attacks occurred in a public space, like a park or street. Significantly more attacks occurred during the summer months (a seasonality that is also true with bites to humans). In the majority of news articles, 1 dog initiated the bite/attack (72.8%; 110). The remaining cases involved 2 (17.2%; 26), 3 (5.3%; 8), 4 (2.6%; 4), or an unspecified number of dogs (0.7%; 1). The most commonly reported breed to initiate attacks was the Staffordshire bull terrier (25.5%; 48), states the study.
The UK banned several fighting breeds in 1991, including the American pit bull terrier, but the Staffordshire bull terrier was not among them.
In the US, a pit bull is a class of dogs, which includes: American pit bull terrier, American Staffordshire terrier, Staffordshire bull terrier and their mixes. Taking the US definition of a pit bull into account, our results of the same study table show that the "staffie bull/pit bull (all)" category was actually (39.9%; 75), followed by the "bullmastiff/mastiff (all)" category with (8.0%; 15). Nearly half of all attacks in the UK study, 48%, were carried out by pit bull and bull-baiting mastiff breeds.
We not only combined the "staffie bull/pit bull (all) = 75" category, we combined all breeds when cross breeds were counted as a separate breed. For instance, our "akita (all) = 8" category includes, akita, akita cross and Japanese akita cross; our "rottweiler (all) = 7" category includes rottweiler and rottweiler cross; and our "bullmastiff/mastiff (all) = 15" category includes bullmastiff, mastiff and Italian mastiff. View how the UK study categorized cross breeds as separate breeds.
Results of combining pure breeds and cross breeds in the UK dog-on-dog attack study.
Given that we are discussing pit bull breeds and the scant number of studies that do address dog-on-dog aggression and attacks, it's relevant to point out that a 2019 Netherlands study states that 56% of the "dog-killing dogs" seized by police were of the "American Staffordshire/pit bull terrier type." These dogs had "dog-killing aggression," which resulted in the death or severe injury of the victim dog. This data was obtained from Dutch police reports -- not news media articles.3
Breed types of these 128 attackers as derived from police reports are listed in Table 1. These 128 dogs killed a total of 72 dogs. Table 1 shows that more than half of the dogs (56% of 128 dogs) were labeled by owners and/or the authorities as American Staffordshire/pit bull terrier type, and killed 28 dogs (54% of 72 killed dogs) and severely wounded 24 dogs (57% of 42 victims). (Schilder, 2019)
Size of Attacking Dogs
In the UK study, 92 (59.4%) of the 155 attackers involved a medium-sized dog, 23 (14.8%) involved a medium-large-sized dog, 38 (24.5%) involved a large-sized dog and 2 (1.3%) involved a small-medium-sized dog. "Significantly more attacks" were "carried out by a medium-sized dog than expected," states the study. Why is this unexpected? Of the 92 medium-sized dogs, 75 (82%) fell into the "staffie bull/pit bull (all)" category, a dog breed that was engineered for "dog killing."
The majority of attacking dogs (59.6%; 90) were not leashed. The owner of the attacking dog only intervened in 19.2% of cases. Of the 29 cases of intervention, (48.3%; 14) involved the owner actually pulling their dog away, 17.3% involved the owner attempting to pull their dog away and 20.7% of the attacks were stopped by the owner by punching or kicking their dog. In all instances (100%) when the owner of the attacking dog intervened, the victim dog still sustained injuries.
In the small number of cases when the owner of the attacking dog intervened, none did so fast enough to stop injuries from being sustained.
Size of the Victim Dogs
Breed of the victim dog was known in (81.9%; 127) of cases and size could be assessed. Of these cases, (70.1%; 89) involved a small-sized dog. There were "significantly more victims being a small-sized dog than expected," states the study. Why is this unexpected? Anyone who pays attention to this issue knows that pit bulls are primarily attacking small dogs for sport. Yorkshire terriers, cocker spaniels and chihuahuas were the most likely to be attacked in the UK study.
The size of the victim dogs was also discussed in the Netherlands study. 94 of the 114 victims (83%) of dog-on-dog attacks were small-sized dogs. When breed was known, chihuahuas, Jack Russell terriers and Yorkshire terriers were the most frequent victims of dog-killing aggression. "These findings show that small dogs are the predominant type of victims" in our study. The study also listed anecdotes by owners of attacking dogs, such as: My dog "cannot stand small dogs."
Physical & Emotional Injuries
In the UK study, (69.5%; 105) of attacks resulted in the victim dog requiring veterinary treatment. Of those cases, nearly one-third (32.4%; 34) required surgery. In 32 cases, the cost of veterinary treatment was known. The average cost was £1,881.90 with a range of £75-£9,000 (US $98-11,800). Only 17 articles indicated who paid the cost of veterinary treatment: primarily the victim’s owner (14.3%), insurance (11.4%), crowdfunding (8.6%), and the attacking dog’s owner (8.6%).
The owner of the victim dog was present during the attack in (95.4%; 144) of the 151 reported incidents. In nearly half of these cases (49.0%; 74), the owner of the victim dog intervened. In 54 (35.8%) cases, owners of the victim dogs stated that they had suffered some form of physical or psychological injury. The majority of injuries occurred to the hands (46.3%, 25) or hands and other parts of the body (63.0%, 34). In (85.4%; 129) of cases, the attack was reported to the police.4
Only 23 of the 151 attacks reported the psychological effects on the victim dog in the article. 14 dogs (61.0%) were "traumatized" by the attack, 2 (8.7%) became "fearful of everything," 2 (8.7%) began barking at other dogs, 2 (8.7%) were afraid to go outside, 1 (4.3%) became fearful of other dogs, 1 (4.3%) displayed signs of fear aggression, and 1 (4.3%) had a "change of personality." Conditions ignored by humane organizations that claim to "protect" and "advocate" for dogs.
Summary of Studies
"In the majority of the documented biting incidents, one medium-sized dog, most commonly reported to be an off-leash Staffordshire bull terrier, initiated the attack on a small-sized dog," states the UK study. This result is similar to the Netherlands study, which found that (56%) of dogs seized by authorities for killing or severely wounding other dogs were American Staffordshire and pit bull terrier types. Both studies also showed that small dogs were the most common victims.
Unlike the Netherlands study, the UK study omits that Staffordshire bull terriers were associated with blood sports and dogfighting. The UK study also victimizes the bull breed, despite it being the primary initiator of attacks: "While these findings could be interpreted to suggest that Staffordshire bull terriers are a risk to other dogs, it is important to note that Staffordshire bull terriers are a stigmatized breed and are often perceived as aggressive, unpredictable, and dangerous."5
Despite small dogs being the most frequent victim, the UK study also blames them by generalizing speculations and anecdotes stated in the Netherlands study about them. "It has been suggested," states the UK study, this might in part be due to small breeds "being misidentified as prey" or as a result of "displaying behaviors (e.g., barking, tail up behavior), which might have the effect of provoking an attack." Concluding, "smaller breeds may inadvertently provoke attacks."6
In the UK study, small-sized breeds were the aggressor in 0% of cases. Despite this, there is pervasive small dog victim-blaming in the study.7
Addressing the Questions
Why is there a glaring absence of data -- peer-reviewed and otherwise -- about the most common type of dog attack, dog-on-dog attacks, in the US and UK? Answer: Possibly because the results would be self-evident, just as the UK and Netherlands studies show. Pit bull breeds, which were selected for the blood sport of dog-killing, are inflicting the most severe injury attacks (57%; Netherlands study) and the most dog-killing attacks resulting in death (54%; Netherlands study).
Why else is there a glaring absence of data? Answer: Possibly because investigating the prevalence of dog-on-dog attacks and dog-killing attacks would only provide further evidence that pit bull breeds are correctly "perceived as aggressive, unpredictable, and dangerous," just like the human injury medical studies show in both fatal and nonfatal injury studies. Also, investigating the prevalence of dog-on-dog attacks and dog-killing attacks could result in more breed-specific laws.
Did the absence of data in this purposefully neglected field of study lead the authors to examine the best and only available source of raw data -- news reports? Answer: Yes. This same absence of data is also why our nonprofit uses news reports to capture "breed data" in fatal human attacks inflicted by dogs. As revealed in both this peer-reviewed study and our own work, multi-sourced news articles provide a rich and accurate data set that stands up to the rigors of peer-review.
Of course multi-sourced news articles are only part of what DogsBite.org tracks. We also collect photographs, videos, police reports, coroner reports and legislative materials that arise after a fatal dog mauling.
Why is there a glaring absence of concern about dog-on-dog attacks in the US and UK by institutions and nonprofits that claim to "protect" and "advocate" for dogs? Answer: Again, possibly because investigating the prevalence of dog-on-dog attacks and dog-killing attacks could result in more breed-specific legislation, an outcome that multimillion dollar humane and veterinary organizations sorely want to avoid -- even at the cost of pet dogs lives, especially small dogs lives.
These same humane groups claim that breed-specific laws break the "human canine bond." They often use the slogan, "BSL destroys families" to repeal breed-specific laws. However, they always ignore the horrible physical and psychological trauma done to both owners and pets by bull breeds that horrifically breaks the "human canine bond." They instead sympathize with the "stigmatized" dog-killing aggressors and adopt out dogs with severe dog aggression into our communities.
Is anyone surprised that bull breeds, selected for bull-baiting and dogfighting, topped the charts in the UK and Netherlands studies, and did so by a landslide? Answer: Except for the authors of the studies, no one is surprised. Dogs purpose bred for dog-killing aggression are the most "efficient" dog-killing breeds on earth. It's not rocket science. No one is surprised that racing dogs are the fastest dogs on earth or that herding dogs are the most effective herding dogs on earth either.
Finally, humane groups and pit bull defenders have long attacked the use of news reports to track breeds of dogs involved in fatal dog maulings, yet here is a peer-reviewed study using this very source. How do you think mass shootings are tracked in this country? (View incident and source). How do you think backovers, frontovers and hot car deaths of children are tracked? A collection of news accounts by nonprofits because official sources can be less accurate or worse, absent.
Too Few or Too Many?
Historically, large bodies undercount events when incidents are low. This is a problem with large data sets, such as the US population of 328 million. CDC tracks hundreds of causes of death, including, deaths by being bitten or struck by a dog, but the smaller the number of deaths, the more unreliable the data. The online tracking of mass shootings, also a low incident event, is a relatively new research goal because the government has never defined a "mass shooting."
"Too few" events is not the case regarding violent dog-on-dog attacks. The UK survey estimated that over 100,000 dogs are killed or suffered life-changing injuries due to dog-on-dog aggression in 2017. Roughly 15% of adult UK dog owners had seen their pet attacked by another dog during the period, according to the survey based on 1,003 adults who own dogs. In the US, few animal control agencies even track damaging dog-on-dog attacks; only bites to humans are tracked.
There is obviously little to no tracking by the UK government since a "survey" underwritten by a pet insurance company is one source of data and the other is a peer-reviewed study based on media articles. As required by Dutch regulations, at least dog-on-dog attacks resulting in severe and fatal injuries are tracked by police. Those attacks were dominated by pit bull breeds, as were dog-on-dog attacks studied in the UK study, and attacks compiled annually by Animals 24-7.
Don't Track Any Data
What is the easiest way to lower the prevalence of a disease? Stop reporting it. That is the role that humane groups, which claim to "protect" and "advocate" for dogs have taken in the US. That is the role that veterinary groups have taken here as well (technically, both never started reporting it either). These same groups also try to discredit dog-killing aggression data collected by Animals 24-7, because their goal, apparently, is for no entity to track or quantify dog-on-dog attack data.
The glaring absence of data about the most common type of dog attack in the US, dog-on-dog attacks, is the direct result of multimillion dollar humane and veterinary organizations refusing to collect data or to investigate this area of damaging attacks. They don't want the public to know the self-evident results: fighting breeds are largely responsible. When data does arise, they are quick to victim-blame small-size dogs, who are victimized the most in these horrific attacks.
Further Reading
In a 2006 paper, animal behaviorist Alexander Seymonova touches on some of these issues (Aggressive dog breeds: Document nr. 3). She discusses the "sudden denial" of abnormal aggression and heritability of behavior by professionals in the dog world. She also discusses dog-on-dog attacks and killings, which are vastly more common than attacks on humans. "In fact, there is a slaughter of ordinary, non-aggressive household dogs" occurring on the streets, she states.
Some of the small dog breeds frequently injured or killed in dog-on-dog aggression attacks.
277 million is derived from the AVMA's 2017–2018 edition of the Pet Ownership and Demographics Sourcebook.
3Intraspecific killing in dogs: Predation behavior or aggression? A study of aggressors, victims, possible causes, and motivations, by Schilder, et al., Journal of Veterinary Behavior, 34 (2019) 52e59.
4In the UK study, 85.4% of the dog-on-dog attacks were reported to the police. This is an exceptionally high percentage and points to the UK Dangerous Dogs Act. In the UK, "It’s against the law to let a dog be dangerously out of control anywhere, such as: in a public place, in a private place, for example a neighbor’s house or garden, in the owner’s home. The law applies to all dogs,"states the government's website. "Your dog is considered dangerously out of control if it: injures someone or makes someone worried that it might injure them. A court could also decide that your dog is dangerously out of control if either of the following apply: it attacks someone’s animal or the owner of an animal thinks they could be injured if they tried to stop your dog attacking their animal." The penalty if your dog is considered "dangerously out of control" includes: unlimited fines, prison time (up to 15 years if you allow your dog to kill a person), your dog subject to destruction and the inability to own a dog in the future, states the website.
5Several UK websites report that shelters are "inundated with requests to take in staffies and their crossbreeds because of the growing numbers being over-bred and abandoned," much like how pit bulls are over-bred and flood shelters in America. One of the websites cited by the study does state the history of the breed "Dating back to the 1800’s, the Staffordshire Bull Terrier was mainly bred for ratting, bull baiting and dogfighting." (dogstrust.org.uk).
6The Netherlands study specifically stated, regarding the anecdotes and speculations of why smaller dog breeds were the majority of victims: "This data set does not allow for the conclusion that generally smaller dogs are more likely to be attacked than larger dogs, and conclusions about motivations are speculative."
7It is generally agreed upon that dog-on-dog aggression is common, in that it is largely comprised of "ritualized aggression" (barking, growling, showing teeth, etc) in an effort to avoid real aggressive encounters. Dog-on-dog "killing aggression" (inflicting severe and fatal injuries to dogs) is much less common, and is what the UK and Netherlands studies investigate. Thousands of years of "ritualized aggression" and tolerance by domesticated dogs among each other, in an effort to avoid damaging aggressive encounters, should be able to withstand the "barking or tail up behavior" by a small dog without this leading to uncommon dog-killing aggression. Small dogs "being less obedient" than larger dogs, as the UK study reports, also should not lead to uncommon dog-killing aggression.
Related articles:
01/28/21: Why Aren't Dangerous Dog Owners Charged With Animal Cruelty? by Dog Lover
09/17/10: Craven Desires: Weekly Frankenmauler Round Up Collection -- Mostly Small Dogs
05/05/09: Alexandra Semyonova: Heritability of Behavior in the Abnormally Aggressive Dog
Thank you, Colleen, for you exhaustive effort to make concrete the sad, tragic facts about dangerous dogs. Anyone who is both cogent and honest knows about and acknowledges the tragic state of affairs. We are indebted to you, Colleen, for providing the detailed situational analysis, and also, for getting the detailed truth out to the world.
I think some other reason small dogs get attacked more, from my personal experiences, is that many small dogs think they’re a lot more dog than they actually are, and their owners failure to leash (after all, it’s not like their dog’s going to kill someone). I’ve had many a small, territorial, unleashed small dog run right up, and even try to attack my much bigger dog. But then again I don’t have a pit bull.
I’m sorry but your speculations aren’t valid! Small dogs in my experience don’t usually run right up and try to attack my big dog (a Rhodesian ridgeback) who actually loves to play with little dogs, who when unleashed at the dog park do run right up and initiate play! I’ve frequently seen them become fearful of a larger dog and disply that! Perhaps you’re seeing aggression in the normal behavior of dogs because of your dislike of small dogs! I actually had a dog that killed a small dog, it wasn’t a pit bull but it was a mix of GSD, husky and undoubtedly wolf (the vet was mistaken no DNA of any kind back then) but he jumped out of the window and killed the little dog with one bite, no growing or warning, the little dog was on our property and hanging out of his mouth like a dead rabbit. so that was that, Except I certainly trusted him less and made sure he didn’t interact with dogs! The Rhodesian ridgeback on the other hand has never been in a dog fight with any dog, is polite and plays nicely now that he’s an adult and when a dog is overly aggressive he usually just leaves and returns to me! Sometimes our preconceived notions tell us things that aren’t really happening! Unless you’ve got some training in animal behavior it’s actually easy to mistake play or fear with aggression.
I’m not sure about the UK, but, here in the US, dog on dog attacks rarely make the news. Even when authorities are involved it’s not newsworthy. And many, many attacks still go unreported to any authority.
Three words: Follow the money.
It’s why these attacks don’t get more documentation and reporting.
Thank you, Colleen, for putting together this article about these studies. For those of us who already know what pit bulls are doing in our communities and to our small pets, this is no surprise and not new news. However, these studies ARE new (2019 & 2020) and for those legislators who are considering passing pre-emption bills or removing pit bulls bans on the basis that “pit bulls are no different than any other dog” (pressured by the pit bull lobby), here we have two academic studies showing they are VERY different… and dangerous. This report could be quite useful in many ways.
My cat was killed by a neighbor’s pit bull, and my toy poodle was severely injured by a different neighbor’s pit bull. I spoke to the county dog warden about my toy poodle, but no reports were ever made about either attack. I believe that’s generally the case, at least in my partially rural area. Because who would even take a report? The owner of the dog that mauled my poodle was already in trouble because the warden picked the dog up as a stray several times. It wasn’t neutered and roamed for years until it just never returned home. They moved away after the attack, but did finally pay most of my vet bill. Even though they moved 15 miles away, their pit showed up at my house years later, still not neutered. I don’t know anyone who has filed a report after an incident like this, so I agree, attacks are underreported.
Thank you so much for this article. I live in the US. A few years ago, I saved my pug (who has since passed away from old age, sadly but thankfully) from an akita attack. I was walking him, and the akita had broken out of its backyard and tried to attack him. Trying to get between them, the akita grabbed my arm and my relative picked up my pug and held him up very high. I have a scar forever, but the akita let go of my arm (after shaking it) and actually listened when my relative yelled at it to go away. If it were a pit bull, I may have gotten mauled, and it definitely would have attacked or jumped on my relative to kill my dog.
The rise of absolute Evil.
Note how everything is been turned upside down, anything good is now bad and anything bad is been promoted, worship and elevated.
Soon , speaking out about PITBULLS will be considered hate speech and will get you labeled as racist.
It’s your new normal.
No surprise here. The stats of the breed(s) responsible mirror those of the known states. These awful pit bull advocates do not see other dog breeds and especially small breeds as equivalent to pits. They are basically worthless to them and “not real dogs.” The veterinary organizations and vet med schools that ignore this do so because there is too much $$$ to be made off of pit bull damage. They can pretend all they want that pits are no different behaviorally, that their bites are no worse. Bold-faced lie!
I know of a situation where a person works at a shelter and takes” Unabke to place pits” she was away and her dog bite one of her other dogs. She then had it put down. This dog is dangerous to everyone for years. She did not want to report it, she did not want the dog taken to the vet. This mindset of save every dog is unrealistic. Dangerous dogs are not good. What about people and small dogs. I have a 5 lb matipoo. I have to be concerned for him and me wherever I go, even in my yard. Every time I open my door I have to be afraid of “pets” of others killing my dog. There has to be something done.