What is the best antibiotic for a cat bite?

Best Antibiotic for Cat Bite Infections

Amoxicillin-clavulanate 875/125 mg twice daily is the first-line antibiotic treatment for cat bite infections due to its excellent coverage against common pathogens including Pasteurella multocida, Staphylococci, Streptococci, and anaerobic bacteria. 1

Rationale for Amoxicillin-Clavulanate

• Cat bites have a high infection rate (20-80%) compared to dog bites (3-18%) 2
• Pasteurella multocida is isolated in over 50% of cat bite wounds 3
• Amoxicillin-clavulanate provides:
  • Coverage against both aerobic and anaerobic bacteria commonly found in cat bites 1
  • 100% susceptibility against Pasteurella multocida 2
  • Protection of amoxicillin from degradation by beta-lactamases 4
  • Effective treatment against other common pathogens including Staphylococcus aureus, Streptococcus species, and anaerobic bacteria 4

Treatment Protocol

1. Initial wound management:

   • Immediate gentle irrigation with water or dilute povidone-iodine solution
   • Thorough cleansing without damaging surrounding tissues 1
   • Avoid suturing when possible to reduce infection risk 1

2. Antibiotic regimen:

   • First-line: Amoxicillin-clavulanate 875/125 mg twice daily 1
   • Duration: Typically 5-7 days for uncomplicated infections 1
   • For cat bites to the hand or deep puncture wounds: Consider extending treatment duration 1

3. Alternative antibiotics (for penicillin-allergic patients):

   • Fluoroquinolones (ciprofloxacin or levofloxacin) plus metronidazole 1
   • Second/third-generation cephalosporins with anaerobic coverage 1
   • Doxycycline (avoid in pregnancy) 1

Special Considerations

• Cat bites to the hand require special attention due to higher risk of treatment failure and may require:

  • More aggressive treatment
  • Possible hospitalization
  • Surgical consultation 1

• High-risk patients requiring broader spectrum antibiotics and closer monitoring:

  • Immunocompromised individuals
  • Elderly patients
  • Patients with cirrhosis or asplenia
  • Those with severe comorbidities 1

Follow-up Recommendations

• Assess response to treatment within 24-48 hours 1
• Monitor for signs of worsening infection (increasing pain, erythema, swelling, purulent drainage) 1
• Consider extending treatment if no improvement after 5 days 1
• Obtain wound cultures if infection is not responding to initial therapy 1, 5

Indications for Hospitalization

• Severe infections with systemic symptoms
• Deep infections involving tendons or joints
• Hand infections not responding to oral therapy
• Immunocompromised patients with moderate to severe infections 1

Common Pitfalls to Avoid

1. Underestimating cat bites: Even small puncture wounds from cats can lead to serious infections due to their sharp teeth introducing bacteria deep into tissues
2. Delayed treatment: Cat bites should receive prompt antibiotic prophylaxis due to high infection risk
3. Inadequate spectrum coverage: Failing to cover both aerobic and anaerobic bacteria
4. Forgetting tetanus prophylaxis: Administer tetanus toxoid if vaccination status is outdated or unknown 1
5. Missing deep structure involvement: Always evaluate for tendon, joint, or bone involvement

Remember that cat bites, particularly to the hand, carry a high risk of infection and should be taken seriously with appropriate antibiotic coverage and close follow-up.