Infection rate of dog bite wounds with primary closure vs. delayed closure or non-closure
Date First Published:
January 18, 2025
Last Updated:
January 18, 2025
Report by:
Kylie Cheung , Emergency Medicine Resident (Queen Mary Hospital )
Search checked by:
Pubmed, Queen Mary Hospital
Three-Part Question:
In [patients with dog bite wounds requiring sutures], does [primary closure of the wound with sutures] [increase rate of infection] compared to delayed closure or non-closure?
Clinical Scenario:
A 60 year old man presented to the A&E with a ~4cm dog bite laceration on the posterior thigh. He has already received all 3 doses of tetanus vaccine. It has been confirmed that the dog is up to date on rabies vaccination. The laceration is deep and requires sutures. Should you do primary closure of the wound?
Search Strategy:
PubMed
Search Details:
PubMed using keywords: dog bite, infection, primary closure
Outcome:
47 papers were found on PubMed, 4 papers were relevant and of sufficient quality for inclusion, 7 papers were not reflective of the outcome in question or of insufficient quality for inclusion, and 36 papers were irrelevant. The relevant papers are listed below.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Dog-bite lacerations: a controlled trial of primary wound closure C Maimaris 1988 September United Kingdom | 96 patients of all ages presenting to the A&E with dog bite lacerations | Prospective, randomised trial Between September 1987 and January 1988, 96 patients entered the trial with 169 wounds: 57 were male and 39 female. The age range was 2-83 years old with 60% of the patients being less then 30 years of age. After randomization, 92 wounds were sutured and 77 were left open. Statistical analysis was carried out comparing the results in the two groups. |
Infection rate | A total of 13 wounds developed infection: seven sutured and six unsutured wounds (not statistically significant). There was no significant difference of infection between the groups. It was concluded that dog-bite wounds should receive thorough surgical treatment and can be safely sutured at presentation. | Small sample size |
| Comparison of primary and delayed wound closure of dog-bite wounds Z Xiaowei Mar-13 China | 120 patients with dog bite wounds | All patients with bite wounds were treated with oral antibiotic medications. We adopted a randomized cohort study, dividing the patients who needed wound closure into two groups: 60 patients for primary closure, and 60 patients for delayed closure, and compared the infection rate and wound cosmetic appearance scores. | Infection rate | In the primary closure group, four people (6.7%) developed a wound infection without systemic infection. In the delayed closure group, three people (5%) developed a wound infection (p = 0.093), but there were not any patients that developed a systemic infection. Primary wound closure for dog bites may be associated with a higher infection rate. | Small sample size |
| Primary closure versus non-closure of dog bite wounds. a randomised controlled trial Nikolaos K Paschos 2014 January Greece | 168 patients with dog bite injuries | The wounds were allocated randomly in two treatment approaches: Group 1, consisting of eighty-two patients, had their wound sutured, whilst Group 2, consisting of eighty-six patients, did not have their wounds sutured. All wounds were cleansed using high-pressure irrigation and povidone iodine. All patients received the same type of antibiotic treatment. | Infection rate | The overall infection rate was 8.3%. No difference in the infection rate between primary suturing and non-suturing group was detected. Primary suturing of wounds caused by dog bites resulted in similar infection rate compared to non-suturing. | small sample size |
| Emergency treatment on facial laceration of dog bite wounds with immediate primary closure: a prospective randomized trial study Chen Rui-feng 2013 July China | 600 patients with facial lacerations caused by dog bite, no prophylactic antibiotics given. | Randomised controlled trial | Infection rate | The infection rate of group A and B was 8.3% and 6.3% respectively (P>0.05). There is no potentiality of increasing infection incidence and infection speed, compared immediate primary closure with the wounds left open. | only studied facial lacerations single center |
Author Commentary:
Three of the papers concluded that there were no significant difference of infection rate between primary closure compared to delayed or non-closure of dog bite wounds, and recommends primary closure. One of the papers concluded that primary wound closure for dog bites may be associated with a higher infection rate, but their conclusion still recommended primary closure due to better cosmetic outcome.
Bottom Line:
Dog bite wounds can be safely sutured at presentation in the emergency department without risk of increased rate of infection. Primary closure of dog bite wounds is recommended due to better cosmetic outcome.
References:
- C Maimaris. Dog-bite lacerations: a controlled trial of primary wound closure
- Z Xiaowei. Comparison of primary and delayed wound closure of dog-bite wounds
- Nikolaos K Paschos. Primary closure versus non-closure of dog bite wounds. a randomised controlled trial
- Chen Rui-feng. Emergency treatment on facial laceration of dog bite wounds with immediate primary closure: a prospective randomized trial study