What antibiotic is recommended for a cat bite?

Antibiotic Treatment for Cat Bites

Amoxicillin-clavulanate is the first-line antibiotic treatment recommended for cat bites due to its excellent coverage against Pasteurella multocida and other common pathogens found in cat bite wounds. 1

Microbiology of Cat Bite Wounds

• Cat bites have a high infection rate (20-80%) compared to dog bites (3-18%) 2
• Pasteurella multocida is found in approximately 75% of cat bite wounds and is the predominant pathogen 1, 2
• Cat bites contain an average of 5 different bacterial species per wound, including both aerobic and anaerobic bacteria 1
• Common organisms include:
  • Pasteurella multocida (found in ~90% of domestic cats' oral cavities) 2
  • Staphylococci and streptococci (found in ~40% of bites) 1
  • Anaerobes (present in 65% of cat bites) including Bacteroides species, fusobacteria, Porphyromonas species, and peptostreptococci 1

First-Line Oral Treatment Options

• Amoxicillin-clavulanate (875/125 mg twice daily) - recommended as first-line therapy based on clinical studies and guidelines 1
• Alternative oral options when amoxicillin-clavulanate cannot be used:
  • Doxycycline (100 mg twice daily) - excellent activity against P. multocida, though some streptococci may be resistant 1
  • Penicillin VK plus dicloxacillin (500 mg four times daily for each) 1

Medications to Avoid for Cat Bites

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

These medications have poor activity against P. multocida and should be avoided as monotherapy for cat bites 1.

Intravenous Treatment Options (for severe infections)

• Ampicillin-sulbactam (1.5-3.0 g every 6-8 hours) 1
• Piperacillin-tazobactam (3.37 g every 6-8 hours) 1
• Second-generation cephalosporins (e.g., cefoxitin 1 g every 6-8 hours) 1
• Carbapenems (e.g., ertapenem, imipenem, meropenem) 1

Special Considerations

• Cat bites have a higher risk of infection than dog bites 2
• Hand wounds from cat bites are particularly concerning and have the highest risk of infection 3
• Infections can progress rapidly, with symptoms appearing within 12-24 hours after the bite 4
• Cat bites can lead to serious complications including:
  • Cellulitis and lymphangitis 4
  • Septic arthritis and osteomyelitis 1
  • Tendonitis 1
  • Rarely, bacteremia and sepsis 5

Treatment Duration

• For uncomplicated infections: 5-7 days of antibiotic therapy 6
• For complicated infections:
  • Osteomyelitis: 4-6 weeks 1
  • Septic arthritis/synovitis: 3-4 weeks 1

Wound Management

• Wounds should be thoroughly cleansed with sterile normal saline 1
• Superficial debris should be removed 1
• Infected wounds should not be closed 1
• Elevation of the injured body part, especially if swollen, accelerates healing 1
• Tetanus prophylaxis should be administered if vaccination status is outdated or unknown 1

Follow-Up

• Outpatients should be followed up within 24 hours either by phone or during an office visit 1
• If infection progresses despite appropriate therapy, hospitalization should be considered 1

Remember that early and appropriate antibiotic therapy is crucial for preventing serious complications from cat bites, particularly for bites to the hand or in immunocompromised patients 6.