Sunday, September 25, 2016

Why Breed Specific Legislation Won’t Help. AKA – Don’t ban my best friend #dontbanmybestfriend

Attacks by dogs are an incredibly divisive and emotive issue. As the majority of victims are children and the attacks are given large media coverage, there is disproportionate attention paid to dog bites by media, the public and ultimately by government. It has been said that ‘dog attacks are small events that can have big political consequences’.1 

Pit-bull type dogs are currently the most commonly affected dogs by a media and public backlash resulting in breed-specific legislation (BSL) being enacted but various breeds of dogs have been demonised, with legislative consequences, for well over a century. From the 19th century vilification of Blood-Hounds through to the ‘Northern Breeds’ (sled dogs like Malamutes and Huskies) and in the 20th century the German Shepherd, Doberman, Rottweiler and now the American Pit-Bull Terrier (APBT) and other pit-bull types. 
As with previous demonization the current reaction to APBTs and pit-bulls is at odds with the empirical evidence.

Interestingly, and unbeknown to many pit-bull critics is the prestigious position occupied by the APBT until relatively recently. The APBT was considered for many decades ‘America’s dog’ and was featured in propaganda posters for recruitment efforts in the world wars.

They were pitched as a stoic, brave national icon. Famous pit-bulls such as Petey from the television show The Little Rascals and sergeant Stubby, a decorated war dog, captured the public imagination. 


A remarkable shift has occurred in recent decades with pit-bulls no longer occupying a treasured place in the American psyche and taking on instead a vilified persona both in the US and abroad. 

Dog Attacks and Fatalities by Breed

It is often cited that “over half of fatal dog attacks are by Rottweilers and Pit-Bull Type breeds”2 and that pit-bull attacks result in higher mortality and morbidity.3 These a priori assumptions, though, lack robustness due to a litany of methodological errors of; reporting bias, over-inclusion, lack of definition of ‘pit-bull type’ with respect to breed, and poor apportioning of dog breed numbers to population totals.
There are between 50 and 70 million dogs in the United States4, 5 with a dog bite incidence of around 4 million per year. Approximately 18% of these bites require some degree of medical attention, with up to 2% severe enough to warrant hospitalisation. Most people are bitten by owned dogs and not strays.4 Dog fatality statistics are much lower. In New Zealand for example, there have been a handful of fatal dog attacks. 
  •          1969, a farmer was killed by a mixed-breed farm dog.
  •          1997, a 59-year-old Te Puke man was killed by two ‘bull-terrier cross’ pig-dogs.
  •          2003, a 73-year-old Northland woman died after being bitten on the foot by one of her three pure-breed Alaskan malamutes.
  •          2004, a 39-year-old Dunedin woman was mauled to death by her pet bull-mastiff
  •          2007, a 56-year-old Murupara woman was attacked and killed by two dogs: a ‘pit bull terrier’ and a Staffordshire cross.6
More recently two fatalities have occurred as the result of one attack by Rottweilers and one by Irish Wolfhounds.

As heart-breaking as any fatalities are, a rational appraisal of the evidence would see these extremely rare events as being unfortunate events that may have been mitigated by better human-canine interactions, but not substantially changed by BSL. To put these figures in perspective, this is a dog-related fatality rate of around 0.15 per year, compared to domestic violence related deaths of around 32 per year. In a 2006 paper in the Journal of Veterinary Behaviour Stephen Collier noted that over the previous twenty years 19 dog fatalities had been recorded in Australia, yet none were verified as being by APBTs.7

In a Dutch survey the highest bite-risk index ratings (a measure of bite risk relative to the dog population and proportion of dogs of that breed) were for breeds: Rottweiler, Doberman, Alsatian, Bouvier des Flandres and Jack Russell Terrier.8 A study in Guelph, Canada stated “Although several breeds had high bite rates, only mixed and German Shepherd breeds had a population attributable fraction in excess of two percent”.9 It is highly likely that dog bites track to a greater or lesser extent the numbers of a type of dog in a given area. For example, in Canada overall, sled-type dogs (Huskies, Malamutes etc.) are responsible for most dog fatalities, with non-fatal incidents also highly featuring Rottweilers, Akitas, Mastiffs and Great Danes.10

Research on dog bite incidents in the City of Toronto suggests merely 4% of bites are perpetrated by American Pit-Bull Terriers and a further 5.5% by ambiguously determined ‘Pit-Bull Cross Types’. These numbers represent a lower risk ratio when compared to numbers of dogs of this type than German Shepherds, Poodles, Golden Retrievers, Beagles, Lhasa Apsos and Shih-Tzu’s (Table 1.). The author of this paper highlights some of the cardinal problems with breed-specific legislation, namely vagueness and over and under inclusions.11 For example, any dog appearing ‘like’ a pit-bull is often recorded as a pit-bull. Similarly, any medium-to-large black and tan breed is often misidentified as a German Shepherd.12 

‘Pit-bull’ has differing definitions, whether considering it as a defined breed, i.e. the American Pit Bull Terrier (APBT) or the ‘pit-bull’ type dog that can include American Staffordshire Terriers, American Pit Bull Terriers, English Bull Terriers, English Staffordshire Terriers, American ‘Bullies’ and sometimes American Bulldogs and other types.12 When we consider numbers of purported ‘pit-bull’ attacks we need to ask ourselves whether the perpetrator was in fact, a pit-bull (APBT) or APBT-cross or was one of upwards of six breed-types. 
Australian research on dog bites has noted: “Identification by breed proved unreliable, however, because of the uncertainty of breed assignment by owners and interviewers, particularly for cross breeds. Importantly, the term “pit bull” appears to be used for several breeds including the bull terrier, American Staffordshire bull terrier (also known as American pit bull terrier), and Staffordshire bull terrier. Confusion may be perpetuated by the media misinforming the public regarding dog breed.”13

Table 1. Dog bites by breed in Toronto, Canada. 

This confusion can continue to perpetuate myths of pit-bull aggressiveness. Reports of dog attacks from Prince Georges County in Maryland, cited by Patronek and colleagues5 show that pit-bull type breeds account for 12% of attacks. Golden Retrievers, on the other hand, account for 6%. This appears that Pit-Bull breeds account for twice as many dog attacks, however, if we consider that pit-bull types are likely to account for around six known breeds then when attacks are amortized across breeds then Golden Retrievers are three-times as dangerous. In this paper the authors go on to demonstrate that even if BSL were effective (which the empirical data shows it is not) the numbers-needed-to-ban would be so high as to make BSL unworkable, dis-economic and without an appreciable effect on dog bites and fatalities; “It is our belief that BSL is based largely on fear.”5

Analysis of breed-type in animal adoption agencies has shown that 87.5% of the dogs identified as having specific breeds in their ancestry did not have all of those breeds detected by DNA analysis, leading the authors of this study to state “The discrepancies between opinions of adoption agencies and identification by DNA analysis suggest that it would be worthwhile to re-evaluate the reliability of breed identification as well as the justification of current public and private policies pertaining to specific dog breeds.”14 Simpson and colleagues summarise the evidence for breed identification and an extremely low ability to positively identify breed and traits based on appearance in veterinary practice in a 2012 article in the Journal of the American Veterinary Association.15

Ineffectiveness of Breed Specific Legislation

Breed-specific legislation has proven to be ineffective and it unfairly penalises safe owners and dogs.16  In Attacking the Dog-Bite Epidemic: Why Breed-Specific Legislation Won't Solve the Dangerous-Dog Dilemma (Fordham Law Review) Safia Hussain cites evidence that breed-based legislation ignores known facts: All dogs can and do inflict injury regardless of breed, breed alone is not dispositive of human aggression, any dog can be bred and trained to be aggressive. Breed-specific legislation may also perversely increase public risk by creating a false sense of security around supposedly ‘safe’ dogs.17

Breed discrimination has no basis in scientific fact. No study has accurately counted or even estimated number of verified dog bites per breed and people are unable to reliably report breed-type— “Without accurate data on the number of bites per breed and the number of dogs per breed, it is scientifically impossible to conclude that one breed is more dangerous than another”.18

An analysis of dog bite incidents in Spain showed that BSL had failed for two major reasons: 1) ‘dangerous’ breeds were not highly represented in dog-bite incidents before legislation was introduced and 2) legislation had little effect on dog bite incidence. However, a strong correlation was found between population density and bite incidence, suggesting that human-canine proximity and numbers led to more incidents rather than breed being a factor.19
Other research, though, shows a small decrease in hospitalisations from dog attacks in Spain over the period from 1997 and 2008 and this has been suggested to possibly relate to stricter licensing requirements for dangerous and large, powerful breeds.20
Surveys from Canada have shown that there is no difference in dog bite rates between municipalities with and without BSL.21

Temperament and Aggression

The innate ‘temperament’ of a breed is often stated as a reason for BSL. The rationale is that pit-bull types have been bred to be aggressive and to be aggressive towards humans. Both of these prima facie statements are patently false. Pit-bull terriers were bred as pit-dogs and companion dogs. Therefore, they were bred primarily for ratting, baiting, dog-fighting and as general ‘around home’ dogs. They have not had a significant use as guarding dogs or patrol dogs until recent times. That notwithstanding, multiple studies have demonstrated that there is no significant difference between breeds for temperament and aggression. Following BSL in Lower-Saxony, temperament tests of 415 dogs from banned breeds was undertaken. The authors concluded that: “The results show no indication of dangerousness in specific breeds. Justification for specific breed lists in the legislation was not shown.”22 This data was subsequently analysed against a ‘control’ group of a breed generally recognised as safe, the Golden Retriever. No significant differences were found between ‘dangerous breeds’ and Golden Retrievers, leading to BSL being withdrawn in this jurisdiction.23 Similarly, most dogs do not exhibit aggression in multiple contexts, suggesting that it is a learned behaviour. Female neutered dogs have a reduced risk of aggression but analysis has identified no specific increased individual breed risks.24

The Myth of Lock-Jaw and Bite-Force

It is commonly stated that pit-bulls have a bite force higher than other dogs, or inordinately high and that they have a ‘lockjaw’ (an inability to let go once locked onto a limb). Both of these claims are untrue. Patronek and colleagues note that at least four scientific studies state a bite-force of 1800 psi for a Pit-Bull, without citing any scientific evidence for the claim.25 In the only research I can find to evaluate differences in bite strength it appears that bite-force is related to the size of the dog. A pit-bull is actually a relatively small dog and exhibits a lower bite force than many other breeds. 
A National Geographic investigation found that of three breeds the following bite forces were found: Rottweilers, 328 pounds of bite pressure; German Shepherds, 238; American Pit Bull Terrier came in third with 235 pounds of pressure. 
Note – this is significantly less than the 400 pounds, average bite pressure of a wolf. 

Likewise, there is no scientific credence to there being a morphological difference in the cranial anatomy of the pit-bull to indicate any type of ‘lock-jaw’ mechanism.

All Dogs Can and Do Bite…

It can be concluded that there are breeds that bite more often, but these are not limited to purported ‘dangerous breeds’ and include broad categories of dogs such as terriers, working-dogs, and herding dogs.26 These breeds, represented highly on dog-bite statistics, although not always overwhelmingly so, are confounded by many other canine and human socio-economic factors. These factors include being a sexually intact male dog of pure-bred status. The breed characteristic of a dog is also confounded by the ‘non-dog’ factors related to bites. 
Perhaps most tellingly, biting dogs were more likely than nonbiting dogs to live in neighbourhoods with lower-than-median income levels26 and there could well be a tendency for supposed ‘dangerous’ breeds to be found in higher numbers amongst people who have a tendency to maintain their animals irresponsibly.12

In dog-bite related fatalities (DBRFs) many factors are thought to play a role, with breed not being one of these. Co-occurent factors for DBRFs include:
  •            absence of an able-bodied person to intervene
  •           incidental or no familiar relationship of victims with dogs
  •           owner failure to neuter dogs
  •           compromised ability of victims to interact appropriately with dogs
  •           dogs kept isolated from regular positive human interactions versus family dogs
  •           owners’ prior mismanagement of dogs
  •           owners’ history of abuse or neglect of dogs27

A dog's appearance has a strong correlation to peoples’ responses to it. Pit-bull types elicit more fear than other breeds due to their appearance28 and this could result in more apprehension and adverse events with interactions with the dog.

Education strategies can encourage safer behaviours for children around dogs. 
“Children who had received the intervention displayed appreciably greater precautionary behaviour than children in the control schools (table). They were circumspect, typically observing the dog from a distance. Most of the children in the control group (118 of 149, 79%) patted the dog without hesitation and tried to excite it, while only a few (18 of 197, 9%) of the children who had received the intervention patted the dog, and they did this surreptitiously or after a considerable period of careful assessment only.”29


The harm caused by dog bites overall is very low when compared to other risks in society. The attention paid to dog bites is out of all proportion to the actual risk. While not minimising the effect of dog bites on victims, BSL is a poor way to reduce risk when compared to other interventions.
Any dog can bite and cause harm and any breed that is large, powerful and has a tenacious temperament can cause appreciable harm to an individual.
However, pit-bull type dogs are no more dangerous than other breeds that are similarly athletic. The only breed-specific legislation likely to work would be to ban all dogs over a certain size.

Any legislation must look pragmatically at cost-to-benefit both financially and societally (i.e. in that dogs offer many benefits to society for physical activity, stress mitigation, improved mental health and transference of values related to animal welfare) and should recognise the role of individual dog owners and individual dogs in adverse human-canine events, rather than breeds.

If you want to stop breed discrimination in NZ please sign the SPCA petition below. 

1.            Lodge M, Hood C. Pavlovian policy responses to media feeding frenzies? Dangerous dogs regulation in comparative perspective. Journal of Contingencies and Crisis Management. 2002;10(1):1-13.
2.            Sacks JJ, Sinclair L, Gilchrist J, Golab GC, Lockwood R. Breeds of dogs involved in fatal human attacks in the United States between 1979 and 1998. Journal of the American Veterinary Medical Association. 2000;217(6):836-40.
3.            Bini JK, Cohn SM, Acosta SM, McFarland MJ, Muir MT, Michalek JE. Mortality, mauling, and maiming by vicious dogs. Annals of surgery. 2011;253(4):791-7.
4.            Overall KL, Love M. Dog bites to humans—demography, epidemiology, injury, and risk. Journal of the American Veterinary Medical Association. 2001;218(12):1923-34.
5.            Patronek GJ, Slater M, Marder A. Use of a number-needed-to-ban calculation to illustrate limitations of breed-specific legislation in decreasing the risk of dog bite–related injury. Journal of the American Veterinary Medical Association. 2010;237(7):788-92.
6.            Healey D. Fatal dog bites in New Zealand. The New Zealand Medical Journal (Online). 2007;120(1259).
7.            Collier S. Breed-specific legislation and the pit bull terrier: Are the laws justified? Journal of Veterinary Behavior: Clinical Applications and Research. 2006;1(1):17-22.
8.            Cornelissen JMR, Hopster H. Dog bites in The Netherlands: A study of victims, injuries, circumstances and aggressors to support evaluation of breed specific legislation. The Veterinary Journal. 2010;186(3):292-8.
9.            Szpakowski NM, Bonnett BN, Martin SW. An epidemiological investigation into the reported incidents of dog biting in the City of Guelph. The Canadian Veterinary Journal. 1989;30(12):937-42.
10.         Raghavan M. Fatal dog attacks in Canada, 1990-2007. Canadian Veterinary Journal. 2008;49(6):577-82.
11.         Bandow JH. Will breed-specific legislation reduce dog bites? The Canadian Veterinary Journal. 1996;37(8):478-81.
12.         Lockwood R, Rindy K. Are “Pit Bulls” Different? An Analysis of the Pit Bull Terrier Controversy. Anthrozoös. 1987;1(1):2-8.
13.         Ozanne-Smith J, Ashby K, Stathakis VZ. Dog bite and injury prevention—analysis, critical review, and research agenda. Injury Prevention. 2001;7(4):321-6.
14.         Voith VL, Ingram E, Mitsouras K, Irizarry K. Comparison of Adoption Agency Breed Identification and DNA Breed Identification of Dogs. Journal of Applied Animal Welfare Science. 2009;12(3):253-62.
15.         Simpson RJ, Simpson KJ, VanKavage L. Rethinking dog breed identification in veterinary practice. Journal of the American Veterinary Medical Association. 2012;241(9):1163-6.
16.         Burstein D. Breed Specific Legislation: Unfair Prejudice & (and) Ineffective Policy. Animal l. 2004;10:313.
17.         Hussain SG. Attacking the Dog-Bite Epidemic: Why Breed-Specfic Legislation Won't Solve the Dangerous-Dog Dilemma. Fordham L Rev. 2005;74:2847.
18.         Cunningham L. The case against dog breed discrimination by homeowners' insurance companies. Connecticut Insurance Law Journal. 2004;11(1):5.
19.         Rosado B, García-Belenguer S, León M, Palacio J. Spanish dangerous animals act: Effect on the epidemiology of dog bites. Journal of Veterinary Behavior: Clinical Applications and Research. 2007;2(5):166-74.
20.         Villalbí JR, Cleries M, Bouis S, Peracho V, Duran J, Casas C. Decline in hospitalisations due to dog bite injuries in Catalonia, 1997–2008. An effect of government regulation? Injury Prevention. 2010;16(6):408-10.
21.         Clarke NM, Fraser D. Animal control measures and their relationship to the reported incidence of dog bites in urban Canadian municipalities. The Canadian Veterinary Journal. 2013;54(2):145-9.
22.         Schalke E, Ott SA, von Gaertner AM, Hackbarth H, Mittmann A. Is breed-specific legislation justified? Study of the results of the temperament test of Lower Saxony. Journal of Veterinary Behavior: Clinical Applications and Research. 2008;3(3):97-103.
23.         Ott SA, Schalke E, von Gaertner AM, Hackbarth H. Is there a difference? Comparison of golden retrievers and dogs affected by breed-specific legislation regarding aggressive behavior. Journal of Veterinary Behavior: Clinical Applications and Research. 2008;3(3):134-40.
24.         Casey RA, Loftus B, Bolster C, Richards GJ, Blackwell EJ. Human directed aggression in domestic dogs (Canis familiaris): Occurrence in different contexts and risk factors. Applied Animal Behaviour Science. 2014;152:52-63.
25.         Patronek GJ, Bradley J, Cleary D. Who is minding the bibliography? Daisy chaining, dropped leads, and other bad behavior using examples from the dog bite literature. Journal of Veterinary Behavior: Clinical Applications and Research. 2016;14:17-9.
26.         Shuler CM, DeBess EE, Lapidus JA, Hedberg K. Canine and human factors related to dog bite injuries. Journal of the American Veterinary Medical Association. 2008;232(4):542-6.
27.         Patronek GJ, Sacks JJ, Delise KM, Cleary DV, Marder AR. Co-occurrence of potentially preventable factors in 256 dog bite–related fatalities in the United States (2000–2009). Journal of the American Veterinary Medical Association. 2013;243(12):1726-36.
28.         Gazzano A, Zilocchi M, Massoni E, Mariti C. Dogs' features strongly affect people's feelings and behavior toward them. Journal of Veterinary Behavior: Clinical Applications and Research. 2013;8(4):213-20.
29.         Chapman S, Cornwall J, Cornwall J, Righetti J, Sung L. Preventing dog bites in children: randomised controlled trial of an educational intervention. BMJ. 2000;320(7248):1512.