Small dogs are often more dangerous than larger ones. This is the rather counter-intuitive observation revealed by a study by the University of Sao Paulo, relayed by the DailyMail January 13, 2023. Indeed, according to Brazilian researchers, the heaviest dogs tend to be more obedient than those who are not. To reach this conclusion, they were interested in the factors that interfere with the aggressiveness of these animals. To do this, they used a sample of 665 dogs, of 57 different breeds and sizes. Their masters had to submit to three different questionnaires to be completed online. The first had attraction to themselves. The second was about the characteristics of their pet. And the last was interested in the nature of any aggressive behavior, such as barking or attacking.
Differences in aggressiveness according to the size of the skull
The result is clear: the heavier the dog, the less likely it is to display aggressive behavior. It was the small dogs with a short muzzle that proved to be the most aggressive of the panel. Flavio Ayrosa, first author of the study, explained to the Daily Mail that: “Aggression towards the owner was 79% more likely in brachycephalic dogs than in mesocephalic dogs.” Brachycephalic dogs have short, squat faces. Among them are pugs, bulldogs, Boston terriers and shih tzus. Mesocephalic races such as beaglesgolden retrievers and labrador retrievers have more intermediate skulls.
Differences in aggressiveness according to the sex of the animal and the owner
In addition, another important factor seems to be taken into account in the aggressiveness of the dog: its sex. According to Flavio Ayrosa, “the probability of aggressive behavior towards the owner was 40% lower in female dogs than in males”. Aggression is also stronger according to the sex of the owner. The study shows that aggression in dogs is 73% more common in male owners than in females.