What is the management approach for a patient with a cat bite, considering potential complications such as infection, tetanus, and rabies?

Cat Bite Management

All cat bite wounds should receive immediate thorough irrigation with sterile saline, prophylactic amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days (especially for hand wounds or wounds near joints/bones), tetanus prophylaxis if indicated, and should NOT be closed except for facial lacerations. 1

Immediate Wound Care

• Irrigate the wound immediately and thoroughly using a 20-mL or larger syringe with sterile normal saline or water to generate adequate pressure and reduce bacterial load 1
• Remove only superficial debris—avoid aggressive debridement that unnecessarily enlarges the wound 1
• Do NOT use iodine- or antibiotic-containing solutions for routine cleansing 1

Common pitfall: Over-aggressive debridement can worsen outcomes by creating larger wounds that are more prone to infection 1

Antibiotic Prophylaxis and Treatment

First-Line Therapy

• Amoxicillin-clavulanate 875/125 mg twice daily is the first-line antibiotic, providing essential coverage against Pasteurella multocida, which is isolated in over half of all cat bite wounds 1, 2
• Duration: 3-5 days for prophylaxis, 7-10 days for established infection 1

High-Risk Wounds Requiring Prophylaxis

• All hand wounds require prophylactic antibiotics due to high infection risk and potential penetration into synovium or bone 1
• Wounds near joints or bones require prophylactic antibiotics 1

Evidence note: While a Cochrane review found no overall benefit of prophylaxis for cat bites, hand bites specifically showed significant infection reduction (NNT=4) 3. The most recent guidelines prioritize hand wounds as high-risk 1.

Penicillin-Allergic Patients

• Doxycycline 100 mg twice daily is the recommended alternative 1
• Avoid first-generation cephalosporins, macrolides, or clindamycin alone due to poor activity against Pasteurella multocida 1

Severe Infections Requiring IV Therapy

• Use ampicillin-sulbactam, piperacillin-tazobactam, second-generation cephalosporins, or carbapenems 1
• Extended therapy: 3-4 weeks for septic arthritis, 4-6 weeks for osteomyelitis 1

Wound Closure Decisions

• Do NOT close cat bite wounds except for facial lacerations 1
• Facial wounds can be closed primarily ONLY after meticulous irrigation and debridement, with concurrent prophylactic antibiotics 1
• For non-facial clean wounds seen early, use Steri-Strips instead of sutures if approximation is needed 1
• Never close infected wounds showing purulent discharge, erythema, or signs of established infection 1

Critical distinction: Cat bites typically create deep puncture wounds that trap bacteria, making closure dangerous unlike dog bites which create lacerations 4, 2

Tetanus Prophylaxis

• Administer tetanus toxoid 0.5 mL intramuscularly if vaccination status is outdated or unknown 1
• All cat bites are considered dirty wounds: booster needed if >5 years since last dose 1
• For clean wounds (not applicable to cat bites): booster needed if >10 years since last dose 1

Rabies Prophylaxis

• Rabies prophylaxis is generally NOT required for domestic cat bites in the United States 1
• Small mammals including domestic cats are rarely infected with rabies 1
• Consider prophylaxis ONLY for feral or stray cat bites in high-prevalence areas after consultation with local health departments 1
• If indicated: administer both rabies immunoglobulin and vaccine to previously unvaccinated individuals 1

Special Populations

Immunocompromised and HIV-Infected Patients

• HIV-infected patients face increased risk of Bartonella infection (cat scratch disease) from cat bites and scratches 1
• Wash cat bite and scratch sites promptly 1
• Do NOT allow cats to lick open wounds 1
• Implement flea control to reduce Bartonella transmission risk 1
• Consider hospitalization if immunocompromised with signs of infection 1

Follow-Up and Monitoring

• Elevate the injured extremity to reduce swelling 1
• Follow-up within 24 hours by phone or office visit is mandatory for all outpatients 1
• Monitor for signs of infection: increasing pain, redness, swelling, purulent discharge 1
• Hospitalize if infection progresses despite appropriate antibiotics, deep tissue involvement is suspected, or patient is immunocompromised 1

Key monitoring point: Cat bite infections can progress rapidly to serious complications including septic shock, meningitis, and endocarditis, particularly with Capnocytophaga canimorsus and Pasteurella multocida 4