Antibiotic Treatment for Animal Bites

First-Line Therapy

The American College of Physicians and Infectious Diseases Society of America recommends amoxicillin-clavulanate 875/125 mg twice daily as the first-line treatment for animal bites, due to its superior coverage of polymicrobial flora, including Pasteurella multocida, Staphylococcus aureus, and anaerobes 1
The standard dose of amoxicillin-clavulanate for dog and cat bites is 875/125 mg twice daily 1
For severe infections requiring intravenous therapy, the Infectious Diseases Society of America recommends ampicillin-sulbactam 1.5-3.0 g every 6-8 hours 1

Doxycycline 100 mg twice daily is an acceptable alternative oral agent for animal bites, particularly useful in penicillin-allergic patients, with excellent activity against Pasteurella multocida 1
However, doxycycline has limited activity against some streptococci, which are commonly present in bite wounds, highlighting an important limitation of its use 1

The Centers for Disease Control and Prevention recommend tetanus prophylaxis be updated if not current within 10 years, with Tdap preferred over Td if not previously given 1
Thorough wound irrigation and debridement are critical first steps before antibiotic therapy, as emphasized by the Infectious Diseases Society of America 2
Prophylactic antibiotics show marginal benefit for low-risk dog bites presenting within 12-24 hours, but are recommended for high-risk wounds, such as hand injuries, puncture wounds, or immunocompromised hosts 1

Doxycycline monotherapy may not be sufficient for bites with a high risk of MRSA or anaerobic infections, and combination therapy with metronidazole may be necessary 1
For human bites, doxycycline is acceptable but must cover Eikenella corrodens, staphylococci, and anaerobes 1