What antibiotics are recommended for cat bites?

Antibiotic Treatment for Cat Bites

Amoxicillin-clavulanate is the first-line antibiotic treatment for cat bites, at a dose of 875/125 mg twice daily. 1

Microbiology and Infection Risk

• Cat bites have a high infection rate (20-80%) compared to dog bites (3-18%), making antibiotic treatment essential 2
• Cat bite wounds typically contain multiple bacterial species (average of 5 per wound), with Pasteurella multocida being the most common pathogen (found in approximately 75% of cat bites) 1
• Other common organisms include staphylococci, streptococci, anaerobes (Bacteroides, Fusobacterium, Porphyromonas species), and Capnocytophaga 3, 1
• Hand wounds from cat bites carry the highest risk of infection and require particularly aggressive management 1, 4

First-Line Antibiotic Treatment

• Amoxicillin-clavulanate (875/125 mg twice daily) is recommended as the first-line treatment by the Infectious Diseases Society of America 3, 1
• This antibiotic combination provides excellent coverage against P. multocida (100% susceptibility) and other common pathogens found in cat bite wounds 2
• Early antibiotic treatment is crucial due to the high infection rate, typically lasting 5-7 days for uncomplicated infections 1

Alternative Antibiotic Options

For patients with penicillin allergies, alternative options include:

• Doxycycline (100 mg twice daily) - excellent activity against P. multocida 3, 1
• Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) plus an anaerobic agent (metronidazole or clindamycin) 3, 1
• Trimethoprim-sulfamethoxazole plus metronidazole 1

Antibiotics to Avoid

• First-generation cephalosporins (e.g., cephalexin) - poor activity against P. multocida 1
• Penicillinase-resistant penicillins (e.g., dicloxacillin) alone - inadequate coverage 1
• Macrolides (e.g., erythromycin) - poor activity against P. multocida 1
• Clindamycin alone - misses P. multocida 3, 1

Special Considerations

• For complicated infections involving joints or bones, treatment duration may need to be extended to 3-4 weeks 1, 5
• For cat-scratch disease (caused by Bartonella henselae), azithromycin is recommended (500 mg on day 1, followed by 250 mg for 4 additional days in patients >45 kg) 1
• Intravenous antibiotics may be necessary for severe infections, with options including ampicillin-sulbactam, piperacillin-tazobactam, or carbapenems 3

Common Pitfalls to Avoid

• Delayed treatment - cat bite infections can develop rapidly (within 12-24 hours) 1
• Inadequate antibiotic coverage - using antibiotics with poor activity against P. multocida can lead to treatment failure 1
• Overlooking complications - watch for signs of deeper infection, especially with puncture wounds over joints or tendons 1, 5
• Insufficient wound care - proper cleansing with sterile normal saline is essential in addition to antibiotic therapy 1, 6

Remember that even small cat bite wounds can lead to serious infections due to the high prevalence of P. multocida in the feline oral cavity (approximately 90%), making prophylactic antibiotic treatment appropriate for virtually all cat bites 2.