A descriptive retrospective study was undertaken to evaluate 250 records of dog bites collected by the Guelph Health Unit during 1986 and 1987. The average reported dog bit rate was 160/100,000 people per year. The lower extremities were bitten in 31.3% of cases, hands 26.5%, face 19.7%, torso 10.4%, and arms received 8.4% of bites. Owners of biting dogs were located 97.6% of the time, and 70% of these dogs were vaccinated for rabies. Incidents occurred 60.1% of the time within the dog's home territory, 14.4% on the street, 13% on a neighboring property, 6.3% in parks, 2.4% around schools, 1.4% at stores, and 2.4% others. Forty-one percent of attacks were unprovoked, but most attacks could be explained by the classifications of canine aggression. Although several breeds had high bite rates, only mixed and German Shepherd breeds had a population attributable fraction in excess of two percent.