Canine and human factors related to dog bite injuries.

Objective: To identify physical traits of biting dogs and characteristics of injured persons and dog owners associated with bite situations for use in public health prevention activities.

Design: Retrospective cohort study.

Study Population: Licensed dog and dog bite report data from June 30, 2002, to July 1, 2003, that were obtained from Animal Control Services of Multnomah County, Oregon.

Procedures: To determine the canine and human factors associated with dog bite injuries, the number of bites, dog and injured person characteristics, and the overall canine population were evaluated. Dog owner characteristics at the block group level were defined by use of geographic information system software through 2000 census information based on place of residence.

Results: During the study period, 636 dog bites were reported to Animal Control Services, and 47,526 dogs were licensed in Multnomah County. Risk factors associated with biting dogs included breed (terrier, working, herding, and nonsporting breeds), being a sexually intact male, and purebred status. Male children aged 5 to 9 years had the highest rate of injury (178 bites/100,000 children). Biting dogs were more likely than nonbiting dogs to live in neighborhoods where the residents' median incomes were less than the county median income value ($41,278).

Conclusions And Clinical Relevance: Dog bites continue to be a source of preventable injury. Prevention programs should target owners of sexually intact male and purebred dogs and owners who live in lower income neighborhoods.