We all have a few clichés in mind: Labradors are affectionate and sociable while Pit Bulls and Rottweilers are more aggressive. But, in reality, these personality traits are not really linked to race, indicates a large American study, published in the journal Science. The researchers studied the genetics of more than 2,000 dogs and studied the questionnaires completed by 18,000 owners. Result: at least 80% of a dog’s appearance is linked to its DNA (its size, its coat, the shape of the ears for example), but less than a quarter of the differences in a dog’s personality others can be explained by race and genetics.
Scientists have thus found eleven places in the genome associated with behavioral characteristics. Breed can play a role in whether some dogs are more athletic than others. For example: borders collies are generally quite obedient on average, beagles and bloodhounds tend to howl more than other dogs. But concerning sociability with humans, shyness, or aggressiveness, race explains only 9% of behavioral differences. It is more the environment, the personality, the age and the education of the dog that play.
On the other hand, the life expectancy of dogs varies considerably between breeds. This is the result of another study that looked at over 30,000 dogs from 18 different breeds. It appears that the life expectancy of a dog varies from simple to double: it is the jack russell, the yorkshire and the border collie who live the longest (a dozen years). Spaniels, Labradors and German shepherds are in the middle of the table with an average life expectancy of 10 years, but bulldogs or pugs only have a life expectancy of four to seven years: these are all dogs whose short muzzle, increases health problems.
In general, this study tells us, life expectancy is greater in non-neutered females and small dogs. And according to Guinness World Records, the oldest dog in the world is currently a 21-year-old Chihuahua, the equivalent of 110 years in human age.