What is the best treatment for a cat bite?

Best Treatment for Cat Bite Wounds

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

Microbiology of Cat Bite Wounds

Cat bites have a high infection rate (30-50%) compared to dog bites (5-25%) and require prompt treatment due to their potential severity. 1, 2

• Cat bite wounds contain an average of 5 different bacterial species per wound, with Pasteurella multocida being the predominant pathogen (isolated in 75% of cat bite wounds) 1, 3
• Other common pathogens include Staphylococcus aureus, Streptococcus species, anaerobes (Bacteroides, Fusobacterium, Porphyromonas species), and Capnocytophaga canimorsus 1, 2
• Pasteurella infections can develop rapidly, with symptoms appearing as early as 3 hours after the bite 4

Initial Management

• Thorough wound cleansing with sterile normal saline to remove debris is essential 1
• Debridement of necrotic tissue should be performed if present 1
• Wounds should not be irrigated under pressure as this may spread bacteria into deeper tissue layers 1
• Elevation of the injured body part, especially if swollen, accelerates healing 1

Antibiotic Treatment

First-line Oral Therapy:

• Amoxicillin-clavulanate: 875/125 mg twice daily for adults or 25 mg/kg/day of the amoxicillin component in 2 divided doses for children 1
• Treatment duration is typically 3-5 days for uncomplicated infections, longer for complicated cases 1

Alternative Oral Options (for penicillin-allergic patients):

• Doxycycline: 100 mg twice daily 1
• Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) plus metronidazole or clindamycin for anaerobic coverage 1
• Trimethoprim-sulfamethoxazole plus anaerobic coverage 1

Intravenous Options (for severe infections):

• Ampicillin-sulbactam, piperacillin-tazobactam, second-generation cephalosporins (cefoxitin), or carbapenems (ertapenem, imipenem, meropenem) 1

Antibiotics to Avoid:

• First-generation cephalosporins (cephalexin), penicillinase-resistant penicillins (dicloxacillin), macrolides (erythromycin), and clindamycin alone have poor activity against P. multocida and should be avoided 1

Special Considerations

• Hand Injuries: Cat bites to the hand carry the highest risk of infection and complications, including osteomyelitis and septic arthritis 1, 5
• Immunocompromised Patients: More aggressive treatment may be needed, especially due to risk of Capnocytophaga canimorsus infection, which can cause sepsis 2
• Complications: Watch for signs of tendonitis, septic arthritis, osteomyelitis, or abscess formation, which require longer treatment courses (3-6 weeks) 1
• Tetanus Prophylaxis: Should be administered if vaccination is not current 5

When to Consider Inpatient Treatment

• Severe infection with systemic symptoms
• Deep wounds, especially those near joints or tendons
• Immunocompromised patients
• Wounds requiring surgical intervention
• Failure to respond to oral antibiotics 1

Common Pitfalls to Avoid

• Delaying antibiotic treatment for cat bites, especially hand wounds
• Using antibiotics with poor activity against Pasteurella multocida
• Failing to recognize deep structure involvement (tendons, joints, bones)
• Inadequate wound cleansing and debridement
• Not considering tetanus prophylaxis 1, 4