Dog Breeds Rated for Feistiness

June 26, 2008 -- Little dogs -- think Chihuahuas and Dachshunds -- tend to be feisty, while certain breeds, like Golden and Labrador Retrievers, are as mellow as their reputations suggest, found a new study that identified the most and least aggressive common dog breeds.

Although certain pooches appear to be more cantankerous than others, the study supports the old adage that "there are no bad dogs," since aggression is often balanced by other more beneficial attributes, such as watchdog skills.

"Most dogs are a mixed bag of positive and less desirable traits -- just like people," lead author Deborah Duffy, a research specialist at the University of Pennsylvania's Center for the Interaction of Animals and Society, told Discovery News.

Duffy and colleagues Yuying Hsu and James Serpell collected basic and behavior-related dog data from two separate groups.

The first consisted of members of 11 American Kennel Club recognized national breed clubs, such as The Labrador Retriever Club and The English Springer Spaniel Field Trial Association. The second involved an online survey posted at the university's Web site.

The study, which has been accepted for publication in the journal Applied Animal Behavior Science, represents one of the most extensive of its kind and is the first to report replicated findings of breed differences in aggression, since both of its data sets led to similar conclusions.

Chihuahuas and Dachshunds scored higher than average for aggression directed to both humans and dogs, putting them towards the top of the list.

Akitas and Pit Bull Terriers, which have "bad boy" reputations, mostly scored high for dog-directed aggression. When they did injure humans, however, the injuries tended to be more severe than those inflicted by the scrappy, smaller dogs.

"Small size very likely plays a large role in the development of fear-based aggression among some breeds," Duffy explained. "Smaller dogs may feel more threatened by other dogs and people -- a perception that may be well founded."