From the Guidelines
For prophylaxis after a dog bite, amoxicillin-clavulanate (Augmentin) is the first-line antibiotic treatment, typically prescribed as 875/125 mg twice daily for 3-5 days in adults or 45 mg/kg/day divided twice daily for children, as recommended by the Infectious Diseases Society of America 1. This combination is effective against the polymicrobial nature of dog bite infections, including Pasteurella species, streptococci, staphylococci, and anaerobes commonly found in canine oral flora. Some key points to consider when deciding on prophylactic antibiotics for dog bites include:
- Wound severity and host immune competence, as noted in the guidelines 2
- The risk of infection, which is higher in certain types of wounds, such as those on the hand, face, or genitals; deep puncture wounds; wounds requiring surgical repair; immunocompromised patients; or those with prosthetic joints
- The importance of thorough wound cleaning with soap and water, tetanus prophylaxis if needed, and evaluation for rabies risk based on the circumstances of the bite For patients with penicillin allergies, alternatives include:
- Doxycycline 100 mg twice daily
- A combination of clindamycin (300 mg three times daily) plus either trimethoprim-sulfamethoxazole or a fluoroquinolone like ciprofloxacin, as outlined in the guidelines 1, 3 It's essential to weigh the benefits and risks of prophylactic antibiotics, considering the potential for marginal benefit in low-risk wounds, as discussed in the evidence summary 2.
From the Research
Antibiotic Prophylaxis for Dog Bites
- The use of antibiotics as prophylaxis for dog bites is a common practice to prevent infection.
- According to a study published in 2021 4, amoxicillin-clavulanic acid is an appropriate empirical antimicrobial choice for moderate dog bite wounds.
- Another study from 2022 5 found that amoxicillin-clavulanic acid was the most commonly prescribed antimicrobial for dog bite wounds, and its use was associated with reduced wound severity.
- A randomized controlled trial published in 2010 6 compared the infection rates of dog bite wounds in patients given amoxicillin-clavulanic acid versus placebo, and found that prophylactic antibiotics were cost-effective if the risk of wound infection was greater than 5%.
- The choice of antibiotic should be based on the severity of the wound and the risk of infection, as well as the potential for antibiotic resistance.
Commonly Used Antibiotics
- Amoxicillin-clavulanic acid is a commonly used antibiotic for dog bite wounds, due to its broad-spectrum activity and effectiveness against beta-lactamase-producing organisms 4, 5, 7.
- First-generation cephalosporins are also used, although they may not be as effective against certain types of bacteria 5.
- The use of higher-importance antimicrobials, such as enrofloxacin, may be associated with increased wound severity and antimicrobial polytherapy 5.
Considerations for Antibiotic Use
- The decision to use antibiotics as prophylaxis for dog bites should be based on the individual patient's risk factors and the severity of the wound 6.
- The use of antibiotics should be guided by culture and susceptibility testing, although this is not always performed in practice 5.
- The potential for antibiotic resistance should be considered when selecting an antibiotic, and efforts should be made to promote antimicrobial stewardship 4, 5.