Demographic and aggressive characteristics of dogs in a general veterinary caseload

A retrospective cross-sectional survey of dog-owning veterinary clients was undertaken in 1996 in the three Canadian provinces of New Brunswick, Nova Scotia, and Prince Edward Island, to generate a population of dogs for future use in a more detailed survey on canine behaviour. The questionnaire was designed to detect which dogs had or had not bitten a person living in the same household, and included both demographic and behaviour questions. Twenty veterinary clinics were enlisted to administer the questionnaire to their clientele. Data was collected on 3226 dogs, a response rate of 81.4%. Dogs were predominantly purebred (60.1%) and neutered (71.6%). The Labrador Retriever was the most commonly reported of 110 breeds. There were slightly more female than male dogs, and significantly more female dogs were neutered (P < 0.001). Questions elicited information about three forms of aggression: growling, possessive aggression, and biting. The reported frequencies of aggression problems were significantly associated with age, gender, neuter status, and breed. Biting behaviour was reported for 15.6% of all dogs. The highest frequency of biting was reported for dogs less than 1 year of age. Relative to intact female dogs of at least I year of age, the odds ratio for having bitten a member of the household was highest for neutered male dogs (OR: 3.23; 95% CI: 1.83-5.71), followed by neutered female dogs (OR: 2.13; 95% CI: 1.21-3.75). Similar trends were seen for growling and possessive aggression. Our results indicate that excellent response rates can be achieved in behavioural research by utilising general veterinary practices and their clientele, that canine aggression in a household setting is a frequent problem, and that the relationship between neutering and behaviour warrants further investigation. (C) 2001 Elsevier Science B.V. All rights reserved.