Treatment of common dog bites: infection risk factors.

In a retrospective study of 106 patients with complete follow-up of dog bites treated in the emergency department the following factors greatly increased the risk of infection: age greater than 50 years, delay in seeking treatment, location on an upper extremity, and puncture wounds. Debridement and irrigation decreased the incidence of infection, and sutured wounds were not more likely to become infected than those left open. Prophylactic antibiotics provided no benefit in this series. In the literature, overall infection rates varied widely according to the various patient populations. Up to 50% of infections from dog bites are caused by pasturella multocida, and the remainder by a wide range of organisms, including streptococcus. Ninety-five percent of these organisms will be sensitive to penicillin.