Biting The Hand That Feeds: What Makes A Dog Bite Their Human Companion?

Hundreds of cities in the U.S. have controversial breed-specific legislation concerning aggressive behavior in dogs. So animal activists should become and remain aware of the latest scientific research about this behavior. This literature review by the National Canine Research Council aims to summarize what we know about aggressive canine behavior. This includes information from past studies about the characteristics of the humans and the dogs, prior behavior, and circumstances of the aggressive encounter. It also includes the severity of the injury, location of the injury, and familiarity between the dog and victim.

Unfortunately, many studies past studies have used a wide range of methodologies. Some have had small sample sizes. And the studies have lacked standard definitions. This all prevents any generalizations to be made from the results about all dogs. So this forced the authors to only summarize individual studies. But they do a good job of grouping similar studies together by theme. And they point out the strengths and weaknesses of each project.

The authors start by attempting to find out the number of annual dog bites in the U.S. The most authoritative study on this is part of a survey by the Centers for Disease Control. It reported 4.7 million dog bites in the U.S. each year. A follow-up survey twelve years later showed a decrease to 4.5 million. Most of this decrease was attributable to a 47% drop in bites to children aged fourteen and under.

The size of dog appears to be more important than breed in terms of how likely a dog is to bite. Smaller dogs appear to bite more often. This is especially the case in interactions related to protecting resources, being handled, and being shouted at or struck. But size surprisingly did not correlate with the injury severity. And whether a dog received medical treatment for an injury indicated the severity of the injury.

Multiple studies indicate a link between fear and canine aggression. Dogs who were afraid of men, children, and strangers were more likely to bite than dogs who did not fear these types of people. Most findings indicate that dogs most frequently bite people they know.

Analysis of dogs’ reproductive status, sex, and age has yielded a wide range of results. Often, there has been conflicting data. Such mixed data do not reveal a reliable pattern between sex, neuter status, and biting behavior.

Though the quality of data varied across studies, the trend was that dogs bit male humans significantly more often than female humans for all age groups. But one study reported that the family dog was one and a half times more likely to bite female humans than male humans. Studies reported that unfamiliar dogs and other non-family dogs more frequently bit male humans than female humans.

The largest survey on dog bites revealed that dogs were more likely to bite adults than children. And the rates of medical treatment sought for adults and children were nearly equal.

This overview will be useful to animal activists when dealing with stereotypes about biting and other aggressive behaviors in dogs. The literature has some inconsistencies. But the upshot is that variables like dog breed, size, sex, age, and neuter status appear to explain at least some of the behavioral differences between aggressive and nonaggressive animals. This suggests that factors specific to the experience of individual dogs are very important when trying to explain dog biting.