Wound infection following dog bite despite prophylactic penicillin

Dog bite wounds of 39 children (ages one to 16 years) were cultured and irrigated. Cultures showed various organisms but were of no predictive value for development of infection. By using a table of random numbers, patients were assigned to either oral penicillin V-K (100,000 U/kg/day every 6 h) or placebo for two days. All patients were seen in follow-up in three to four days and again at seven to 10 days or earlier if signs of inflammation occurred. The mean patient age, location and type of wound, and initial wound care were similar in the two treatment groups. Three of 39 (7.7%) children enrolled in the study developed infection at the bite site, including two of 19 in the penicillin group and one of 20 in the placebo group. In our study, prophylactic penicillin failed to prevent infection in dog bite wounds. Good local care on presentation seems to be the most important factor in determining future infection.