Short dogs are more aggressive and harder to control for their owners, a new study suggests.
The shorter the dog, regardless of breed, the more likely it is to march to the beat of its own drum, according to research by the University of Sydney.
"The most comprehensive study undertaken to date, our research shows that certain physical characteristics in dogs are consistently associated with certain types of behaviour," said Professor Paul McGreevy from the University's Faculty of Veterinary Science.
Essentially, the shorter the dogs the less controllable their behaviour is for their owners, said McGreevy.
The study used owners' reports on the behaviour of over 8,000 dogs from across 80 breeds and related them to the shape of 960 dogs of those breeds, revealing strong relationships between height, bodyweight, skull proportions and behaviour.
It discovered that thirty-three, out of thirty-six undesirable behaviours considered, were associated with height, bodyweight and skull shape.
For example, as a breed's average height decreased, the likelihood of behaviours such as mounting humans or objects, owner-directed aggression, begging for food and attention-seeking increased.
The only behavioural trait associated with increasing height was 'trainability'. When average bodyweight decreased, excitability and hyperactivity increased," said McGreevy.
The ratio of skull width to length was an interesting case. Long skulled dogs - such as afghans, salukis and whippets - appear to be a product of selection for chasing characteristics as they excelled on those indicators, researchers said.
"Undesirable behaviours such as owner aggression, or mounting, occur more often among small dogs. This suggests that, in small dogs, these behaviours are tolerated more than they would be in larger dogs where such behaviours are more unwelcome and even dangerous," McGreevy said.
According to owners' reports, they flunked on fear of strangers, barking persistently, and stealing food.
Given hunting dogs have not traditionally been companion animals sharing close quarters with humans this may not be surprising.
The study was published in the journal PLOS One.
