Every study completed to date has found breed specific legislation to be completely ineffective in reducing the incidence of dog bites. Now a study of pet dogs in Spain published in The Journal of Veterinary Behavior, offers new insight into why. The study found that the so called dangerous breeds simply behave no differently from dogs in general when it comes to behaviors likely to lead to biting.
The authors looked for risk factors for various behavior problems as reported by dog owners. They found that dogs identified as belonging to breeds designated as dangerous according to Spanish law were no more likely to behave aggressively toward people or toward other dogs than were dogs of the random group of breeds in the sample.
What the study did find was that the larger the dog (dividing the 232 dogs studied into 3 size categories), the less likely it was to exhibit aggressive behaviors toward people such as barking, growling, snarling lunging, snapping or biting. Large dogs were also less likely to behave fearfully. This is particularly striking with regard to the breeds identified as dangerous according to Spanish law, since most fall into the large dog category and the rest into the medium. Thus they are disproportionately represented within the least aggressive groups the study identified. Another notable aspect of this finding is that it is consistent with a larger study conducted in Canada a decade earlier, (Guy, 2001) suggesting that this inverse relationship between aggression and size may carry over across continents and long periods of time.
In looking at aggression toward their fellow dogs, the study found that gender and age played a role. Males were more likely to show aggression toward other dogs, as were to a small degree, the older dogs in the sample, but dangerous breed identification made no difference.
The researchers conclude simply, that “dogs classified as dangerous do not seem to be more aggressive than the rest.”
The full text article can be purchased at http://www.journalvetbehavior.com/article/S1558-7878(11)00008-6/abstract
Martinez,A.G., Pernas, G.S., Casalta,J.D., Rey,M.L.S., Palomino, L.F,dlC., Risk factors associated with behavioral problems in dogs. Journal of Veterinary Veterinary Behavior (2011) 6, 225-231.