To best understand this article in the context of the literature on growling, snarling, snapping, and biting behavior (incidence and correlates), please see National Canine Research Council's complete analysis here.
National Canine Research Council Summary and Analysis:
This, and the other two papers produced by the same study (Guy et al., 2001a; 2001b), is included because it probably represents the least sample bias of any large scale survey of dogs and owners. In this third in a series of studies of dogs and their owners presenting for treatment in one of 20 veterinary facilities in Maritime Canada, Guy et al. (2001c) aimed to identify the characteristics of 227 dogs and their owners involved in bite incidents. 20 veterinary practices in New Brunswick, Nova Scotia, and Prince Edward Island administered surveys to their dog-owning clientele, (Guy et al., 2001a) which resulted in an 81.4% response rate and the initial pool of 3,226 dogs for this series of studies, from which this study population of 227 dogs was extracted, limited to those whose owners had reported that the dog had bitten a family member, according to a precise definition of a bite, and where an extensive interview ruled out playful mouthing.
Biting was defined as, “The upper or lower teeth making contact with the victim’s skin with sufficient pressure to cause a visible injury such as an indentation, welt, scrape, bruise, puncture, or tear in the skin,” a level of precision seldom seen in the dog bite literature. In fewer than 10% of the cases the person sought medical treatment for the bite and these were almost exclusively bites to the head of the victim. Medically treated bites were more likely to result in owners taking precautions to prevent a recurrence. A wide variety of contexts for the growling, lifting a lip, snapping, lunging and biting were collected under the category of “dominance aggression” although one of the primary authors has since repudiated this as a useful paradigm for describing these behaviors. These contexts included various kinds of handling and restraint, shouting at and threatening the dog, and removing resources. These same dogs were more likely to be described as fearful by the owners (demonstrating fear towards stimuli such as the vacuum, delivery people, men, thunder, riding in the car, or the veterinarian, or simply: strangers, men or other dogs). Collectively, these contexts can all be framed as attempts on the part of the dog to respond to a perceived threat, thus confirming the basic function of warning and biting behavior. The characteristics of biting dogs and their households in this sample included an approximately equal number of male and female dogs (117 and 110, respectively) but a significantly larger proportion of females were spayed than males were neutered. A small majority (58%) of the sample was reported to be purebred. The average number of individuals living in the house was 3.13.
Researchers compared dogs who had or had not produced a bite requiring medical attention and found no differences in weight, sex, reproductive status, or age at neutering. Dogs who caused an injurious bite (a bite requiring medical attention) were older at the time of the first bite incident than those who caused a non-injurious bite (not requiring medical attention). But the owner’s assessment of the seriousness of the bite was elevated if the dog was large and male, even though the actual reported severity was the same.
Among adults (>18), teenagers (13-18), and children (<13), adults were reported to be the most common victims of dog bites; 73.5% of the biting dogs had bitten an adult, 17.9% had bitten a teen, and 21.5% had bitten a child. This is in contrast to the clinical reports that generally identify children as being the most likely victims (Sacks et al., 1996). This may be attributable to children being more likely to be treated for a dog bite but not necessarily more likely to be bitten, or to the exclusion of bites other than those to family members. However, it is impossible to ignore the possibility of this study as presenting a more accurate victim demographic as it does not suffer from the usual bite reporting self-selection bias, although the authors do acknowledge that it does not capture dogs whose owners never present them for veterinary care.