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Aggression and Fear Can Be Reduced in Specific Dog Breeds

Genetics may provide an alternative to breed-specific legislation for dogs

Doug Pieper photo - Creative Content License
Source: Doug Pieper photo - Creative Content License

"Breed-Specific Legislation is not the answer!", was the emphatic exclamation of a colleague of mine. We were attending a psychological conference in Portland Oregon several years ago, and were having breakfast in a fast food restaurant near the hotel where the scientific meetings were being held. The restaurant had a large TV screen tuned to a local news channel which had just reported that a child had been badly bitten by a dog. It was described as "a pit bull terrier" and it looked very much like an American Staffordshire Terrier. The news report was immediately followed by a commentator who stridently demanded that breed-specific legislation be introduced and that targeted "dangerous breeds of dogs" be banned.

My colleague, who is an expert on neuropsychology, continued his harangue, "We know that a dog's personality, including his likelihood to show aggression, is strongly influenced by his genetics [click here for more on that.] So if you control the breeding, and don't allow the aggressive animals to parent any litters, then over time you take that aggressive strain out of any breed that you target.

"Most people don't remember that back in the 1960s the 'devil dogs' that people worried about weren't pitbulls but were Doberman pinschers. One Doberman breeder told me that people like him were afraid that the government was going to slap some sort of 'dangerous dog' legislation on their breed. So they took it upon themselves to ban the breeding of any Doberman pinscher that showed spontaneous aggression — that is aggression which occurs without being provoked. As a result of that action, in a period of only around 10 years, the breed had been modified to the hard-working guard dogs that they are now. These are dogs who will respond to a threat, but no longer have a hair-trigger on their aggression. At least that is true in North America, however in Europe they still like their Dobermans to have what they call 'temperamental fire' which means that they have much more spontaneous aggression. Control the breeding and ultimately you control the aggression — you don't need breed banning legislation."

I remembered that conversation when I came across an article that has just been accepted for publication in the journal Applied Animal Behaviour Science. The investigative team was headed by Joanne van der Borg of the Behavioural Ecology Group in the Department of Animal Sciences at Wageningen University and Research, in the Netherlands. These researchers took advantage of the fact that in the Netherlands an attempt was made to control the genetics of various dog breeds in exactly the way that my colleague had suggested. It worked like this.

Since June 2001, the Dutch Kennel Club began to require a behavior test (the Socially Acceptable Behavior test or SAB) be administered to certain breeds: the Neapolitan Mastiff, Fila Brasileiro, Cane Corso, American Staffordshire Terrier and Rottweiler. The test aims to assess aggressive biting tendencies and extreme fearfulness (which could be a trigger for fear-based aggression). Dogs which failed the test were barred from breeding at least to the extent that any offspring that they parented could not receive a pedigree certificate from the kennel club.

The Dutch Rottweiler Club kept records on Rottweiler dogs that passed or failed the test from 2001 until 2005. So here we have a database which would should allow us to see if controlling the breeding of dogs can reduce aggressive tendencies in the population. At the time of this study there were roughly 7000 pedigreed Rottweilers (meaning that they had parents who had passed the SAB test) and roughly the same number of non-pedigreed Rottweilers (whose parents had failed the test) which the investigators in this study called look-alikes.

A set of questionnaires was then administered to Rottweiler owners. Specifically they used the Canine Behavioural Assessment and Research Questionnaire (C-BARQ) which is a scientifically validated questionnaire that uses the dog owner's responses to measure a variety of different every day behaviors in order to extract personality and behavior tendencies including aggression and fearfulness in their dog. A total of 822 questionnaires were ultimately analyzed.

If my colleague's predictions were correct then in this real-world situation we should find that there is less aggression in the pedigreed dogs whose parents had passed the original SAB screening test. This turns out to be the case in several important categories. The look-alikes (Rottweilers whose parents had not passed the screening test) were more than three times as likely to show stranger-directed aggression than were the pedigreed dogs whose parents had passed the test (16.0% versus 6.4%). This is likely fear triggered aggression since the non-pedigreed dogs were four times more likely to show stranger-directed fear then the look-alikes (4.3% versus 0.9%). The fearfulness scores were also higher in other situations for the look-alikes. They showed more than three times the fearfulness compared to dogs with behaviorally screened parents in non-stranger involved situations (7.8% versus 2.2%).

The researchers then constructed a combined score for the behavior categories that are assessed with the SAB test (stranger-directed aggression, dog-directed fear/aggression, stranger-directed fear and non-social fear). They wanted to know the degree to which these behaviors showed up in subsequent generations of dogs. It turns out that the progeny of the pedigreed Rottweilers who had passed the test were only about half as likely to show problems in any of these areas (17.8% for the pedigrees versus 33.3% for the look-alikes).

The conclusions to be drawn from this research seem to be quite clear. The amount of aggression and fearfulness in Rottweilers seems to be reduced by one half, or in some indexes to only one quarter, in the offspring of dogs whose parents have been screened to determine that they did not have these socially unacceptable behaviors. There is no reason to believe that such results would not occur in other, potentially "dangerous" breeds.

This certainly seems to suggest a reasonable alternative to breed-specific legislation. All dogs, prior to breeding, could be screened for aggressive and fearful tendencies. Those who show these behaviors to a higher degree could then be banned from breeding (perhaps enforcing this by mandatory neutering). Of course this doesn't take into account backyard breeders, puppy mills, irresponsible breeders, or simply opportunistic breeding, but it could still have a major effect on the entire population of dogs. Cutting the number of dogs likely to be involved in aggressive incidents by half is certainly highly significant.

The problem with such a program is that it requires time, as we work our way through generations of dogs, but if it mimics the situation that my colleague noted for Doberman pinschers, and also follows the trend shown in this present study involving Rottweilers, then significant effects might be noticed in a period of 5 to 10 years. But of course this is far too long for politicians and activists, since breed-specific legislation can be imposed quickly and thus allow those in charge to be able the claim that they are solving the problem. Still it is important to note that there is a long term, sensible alternative, which deals with the root problem of canine aggression — genetics — that is available and could be used.

Stanley Coren is the author of many books including: Gods, Ghosts and Black Dogs; The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome

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Joanne A.M. van der Borg, Elisabeth A.M. Graat, Bonne Beerda (2017). Behavioural testing based breeding policy reduces the prevalence of fear and aggression related behaviour in Rottweilers Applied Animal Behaviour Science,

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