Risk factors for dog bites to owners in a general veterinary caseload

A detailed telephone survey of dog owners was undertaken in 1996 to determine the risk factors for biting behaviour of dogs in a household setting. Individuals were selected from a cross-sectional population of veterinary clientele in the Canadian provinces of New Brunswick, Nova Scotia, and Prince Edward Island. Interviews were successfully completed with 515 of 640 individuals selected from a study population of 3226 dogs by a formal random process. For the risk factor analysis, 227 biting and 126 non-biting dogs were selected according to a strict criteria to evaluate the association of potential risk factors to biting behaviour. Biting behaviour was carefully defined in the telephone interview to avoid including activity associated with playful mouthing by the dog. All dogs were at least 6 months of age. Both the mean weight and age of biting dogs were significantly lower (P<0.05) than that of non-biting dogs. Significant risk factors for an outcome of biting were as follows: the dog being female (particularly if small), the presence of one or more teenage children in the home, a history of a pruritic or malodorous skin disorder which had received veterinary treatment, aggression over food in the first 2 months of ownership, the dog having slept on someone's bed in the first 2 months of ownership, and the dog having been given a significantly higher ranking for excitability based on its behaviour in the first 2 months of ownership. Small dogs were also determined to have a higher risk of biting than large dogs when exposed to certain lifestyle and health factors, suggesting a relationship between body size and reactivity, or possibly greater owner tolerance of aggression in smaller dogs. Biting dogs were more likely to have exhibited fear of children, men, and strangers. The risk factors identified provide a useful focus for the veterinarian in general practice when counselling owners in the prevention of canine aggression..