Outcomes After Primary Closure of Animal Bite Wounds

Introduction: Most animal bites heal without difficulty. However, some animal bite wounds lead to infection, and whether animal bite wounds should be left open or sutured remains controversial. This study aimed to evaluate the risk factors for bite-wound infection, and whether primary closure interfered with wound infection.Methods: This was a single-center, retrospective cohort study. The following information was extracted: date of treatment, age, sex, location of the injury, severity of injuries, surgical procedure, the interval between injuries, and primary treatment.Results: A total of 535 patients presented with dog- or cat-bite wounds. Primary closure was performed in 89 patients (17.0%); 73 patients had wound infections (14%). There were no significant differences between infection and age, sex, animal species, wound location, or severity (P = 0.46, 0.35, and 0.30, respectively). However, occurrence of wound infections after primary wound closure increased significantly (P < 0.05). More infections in the head, neck, and lower extremities occurred particularly in the primary closure group than in the open wound group (P < 0.05).Head and neck bite wounds generally exhibit low infection rates owing to the rich blood supply to the area. However, our study showed that the infection rates of head and neck bite injuries were similar to those of the upper and lower extremities.Conclusion: There were many cases of infection after primary suturing, even in the head and neck regions. Therefore, careful follow-up after primary care of bite wounds is required.