Recommended Antibiotic Treatment for Cat Bites
Amoxicillin-clavulanate (875/125 mg twice daily) is the recommended first-line antibiotic therapy for cat bite infections due to its excellent coverage of the polymicrobial nature of these wounds, particularly Pasteurella multocida which is present in 75% of cat bites. 1, 2
Microbiology of Cat Bite Wounds
- Cat bites contain an average of 5 different bacterial species per wound, including both aerobic and anaerobic bacteria 1
- Pasteurella multocida is found in approximately 75% of cat bite wounds and is the predominant pathogen requiring targeted antibiotic coverage 3, 2
- Staphylococci and streptococci are present in approximately 40% of cat bite wounds 1, 2
- Anaerobic bacteria, including Bacteroides species, fusobacteria, Porphyromonas species, and peptostreptococci, are present in 65% of cat bites 3, 2
First-Line Oral Antibiotic Options
- Amoxicillin-clavulanate (875/125 mg twice daily) is the recommended first-line therapy based on clinical studies and guidelines 1, 2
- This combination provides excellent coverage against P. multocida while also addressing other common pathogens in cat bites 4
- Studies have demonstrated 100% susceptibility of P. multocida isolates to amoxicillin-clavulanate 4
Alternative Oral Antibiotic Options (for penicillin-allergic patients)
- Doxycycline (100 mg twice daily) is an excellent alternative with good activity against P. multocida, though some streptococci may be resistant 3, 1
- Penicillin VK plus dicloxacillin (500 mg four times daily for each) is another alternative oral option 1
- Fluoroquinolones (ciprofloxacin 500-750 mg twice daily, levofloxacin 750 mg daily, or moxifloxacin 400 mg daily) can be considered but may not adequately cover MRSA and some anaerobes 3
Antibiotics to Avoid for Cat Bites
- First-generation cephalosporins (e.g., cephalexin) should be avoided due to poor activity against P. multocida 3, 1, 2
- Penicillinase-resistant penicillins (e.g., dicloxacillin) alone should be avoided 1, 2
- Macrolides (e.g., erythromycin) should be avoided due to poor activity against P. multocida 3, 1
- Clindamycin alone should be avoided as it misses P. multocida 1, 2
Intravenous Treatment Options (for severe infections)
- Ampicillin-sulbactam (1.5-3.0 g every 6-8 hours) is a recommended intravenous treatment option 3, 1
- Piperacillin-tazobactam (3.37 g every 6-8 hours) is another recommended intravenous option 3, 1
- Second-generation cephalosporins (e.g., cefoxitin 1 g every 6-8 hours) are effective intravenous options 3, 1
- Carbapenems (e.g., ertapenem, imipenem, meropenem) can be used for severe infections 1
Indications for Hospitalization and IV Antibiotics
- Evidence of systemic infection or sepsis 3, 2
- Rapidly progressing infection despite oral antibiotics 3, 2
- Deep tissue involvement (tendonitis, septic arthritis, osteomyelitis) 3, 1
- Immunocompromised hosts 3, 2
- Need for surgical intervention 3
Treatment Duration
- Standard uncomplicated infections: 5-7 days 2
- Osteomyelitis requires 4-6 weeks of antibiotic therapy 1
- Septic arthritis/synovitis requires 3-4 weeks of antibiotic therapy 1
Important Clinical Considerations
- Cat bite wounds have a higher infection rate (20-80%) than dog bites (3-18%) 4
- Hand bites are at particularly high risk for infection and complications, with evidence supporting prophylactic antibiotics for these wounds 5
- Wounds should be thoroughly cleansed with sterile normal saline and superficial debris removed 1, 2
- Infected wounds should not be closed 1, 2
- Tetanus prophylaxis should be administered if vaccination status is outdated or unknown 1, 2, 6
- Outpatients should be followed up within 24 hours either by phone or during an office visit 1, 2