Treatment for Cat Bite Infections

Microbiology and Treatment

Cat bite wounds have a higher infection rate than dog bites and typically contain mixed aerobic and anaerobic bacteria, with Pasteurella multocida isolated from 75% of cat bite wounds 2
The American College of Physicians recommends considering alternative antibiotics for cat bite infections that do not respond to initial treatment, such as doxycycline 100 mg twice daily, which has excellent activity against P. multocida 1, 2
Anaerobic bacteria are present in 65% of cat bite infections, often concurrently with P. multocida, and may require additional antibiotic coverage 4
The Infectious Diseases Society of America recommends avoiding first-generation cephalosporins, penicillinase-resistant penicillins, macrolides, and clindamycin as monotherapy due to poor activity against P. multocida 3

Doxycycline 100 mg twice daily is a recommended first-line alternative oral therapy, with excellent activity against P. multocida, although some streptococci may be resistant 1, 2
Fluoroquinolones, such as ciprofloxacin 500-750 mg twice daily, levofloxacin 750 mg daily, and moxifloxacin 400 mg daily, are alternative oral options with good activity against P. multocida, but may not cover MRSA and some anaerobes 1, 2

For severe infections requiring IV therapy, ampicillin-sulbactam 1.5-3.0 g every 6-8 hours, piperacillin-tazobactam 3.37 g every 6-8 hours, and second-generation cephalosporins like cefoxitin 1 g every 6-8 hours are recommended options 1, 2
Hospitalization should be considered for patients with evidence of systemic infection, rapidly progressing infection despite oral antibiotics, deep tissue involvement, immunocompromised hosts, or need for surgical intervention 3, 4, 6