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 of choice 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, 3
• Pasteurella multocida is isolated in over 50% of cat bite wounds 4, 2
• Amoxicillin-clavulanate provides protection against beta-lactamase enzymes that might otherwise degrade amoxicillin 5
• Studies show 100% susceptibility of P. multocida to amoxicillin-clavulanate 2
• The Infectious Diseases Society of America and American College of Physicians strongly support this recommendation 1

Treatment Algorithm

1. Initial Assessment:

   • Evaluate wound location (hand bites warrant special attention due to higher risk of treatment failure) 1
   • Assess depth and type of wound (puncture vs. laceration)
   • Check for involvement of deep structures (tendons, joints, bones)

2. Wound Management:

   • Immediate gentle irrigation with water or dilute povidone-iodine solution 1
   • Avoid suturing when possible (increases infection risk) 1
   • Consider Steri-Strips for wounds seen within 8 hours 1
   • Consider delayed primary closure for wounds >8 hours old 1

3. Antibiotic Selection:

   • First-line: Amoxicillin-clavulanate 875/125 mg twice daily 1
   • Alternative options (for penicillin-allergic patients):
     • Fluoroquinolones (ciprofloxacin or levofloxacin) plus metronidazole 1
     • Second/third-generation cephalosporins with anaerobic coverage 1
     • Doxycycline (avoid in pregnancy) 1

4. Treatment Duration:

   • Typically 5-7 days for uncomplicated infections 1
   • May extend if no improvement is seen 1

5. Follow-up:

   • Assess response within 24-48 hours 1
   • Monitor for signs of worsening infection 1

Special Considerations

• Cat bites to the hand require special attention and possibly more aggressive treatment due to higher risk of treatment failure 1
• High-risk patients (immunocompromised, elderly, those with cirrhosis or asplenia) may require broader spectrum antibiotics and closer monitoring 1
• Deep puncture wounds are common with cat bites and may require more aggressive treatment 1
• Consider hospitalization for severe infections with systemic symptoms, deep infections involving tendons or joints, hand infections, or immunocompromised patients with moderate to severe infections 1

Common Pitfalls to Avoid

1. Underestimating cat bites: Despite their small size, cat bites have higher infection rates than dog bites due to their puncture-type wounds and high carriage rate of P. multocida (approximately 90%) 2

2. Delayed treatment: Cat bite wounds can appear trivial initially but can rapidly progress to serious infections if not managed appropriately 4

3. Inadequate coverage: Using antibiotics without coverage for P. multocida (such as dicloxacillin or cephalexin alone) may lead to treatment failure

4. Neglecting tetanus status: Always assess tetanus immunization status and provide prophylaxis if vaccination is outdated or unknown 1, 6

5. Overlooking rabies risk: Consider rabies prophylaxis, especially for feral cat bites 1