How should I manage a cat bite wound, including irrigation, debridement, tetanus prophylaxis, antibiotic therapy, and rabies post‑exposure prophylaxis?

Cat Bite Management

Cat bites require immediate medical evaluation, thorough irrigation with sterile saline, prophylactic antibiotics (particularly for hand wounds), tetanus prophylaxis, and rabies risk assessment—wounds should generally not be closed except on the face. 1

Immediate Wound Care

Irrigation is the single most critical intervention to prevent infection:

• Irrigate thoroughly with copious sterile normal saline or running tap water using a 20-mL or larger syringe to generate adequate pressure for bacterial removal 1, 2
• Continue irrigation until no visible debris or foreign matter remains in the wound 1
• Remove only superficial debris—avoid aggressive debridement that could enlarge the wound and impair closure 1
• Do not use povidone-iodine or antibiotic-containing solutions for routine wound cleansing, as they provide no additional benefit over saline irrigation 1

Explore the wound carefully for:

• Tendon involvement (particularly in hand bites) 2
• Bone or joint capsule penetration (pain disproportionate to injury suggests periosteal penetration) 1
• Foreign bodies including tooth fragments 2

Wound Closure Decisions

Primary closure is contraindicated for most cat bite wounds:

• Do not close cat bite wounds except facial wounds 1
• Infected wounds should never be closed 1
• Facial wounds are the exception: may be closed primarily after meticulous irrigation, cautious debridement, and administration of prophylactic antibiotics (preferably by a plastic surgeon for optimal cosmetic results) 1
• Non-facial wounds may be approximated with Steri-Strips, with subsequent closure by delayed primary or secondary intent 1
• Suturing within 8 hours of injury remains controversial with insufficient evidence to support routine closure 1

Antibiotic Prophylaxis

Prophylactic antibiotics should be administered to all cat bite patients regardless of wound appearance because cat bites carry exceptionally high infection risk, particularly to the hand 1, 3, 4:

First-line oral therapy:

• Amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days (provides coverage against Pasteurella multocida, anaerobes, and other oral flora) 1, 4, 5, 2

Alternative regimens for penicillin allergy:

• Doxycycline 100 mg twice daily 1
• Fluoroquinolone (ciprofloxacin, levofloxacin, or moxifloxacin) plus metronidazole 1, 5
• Moxifloxacin alone (provides adequate anaerobic coverage) 1, 5

Intravenous options for severe infections requiring hospitalization:

• Ampicillin-sulbactam 1
• Piperacillin-tazobactam 1
• Carbapenems (ertapenem, imipenem, or meropenem) 1

High-risk scenarios requiring prophylaxis include:

• Hand wounds (highest infection risk) 3, 4
• Immunocompromised patients 1
• Asplenic patients 1
• Advanced liver disease 1
• Pre-existing or resultant edema 1
• Moderate to severe injuries 1
• Wounds penetrating periosteum or joint capsule 1

Tetanus Prophylaxis

Verify and update tetanus immunization status:

• Administer tetanus toxoid (0.5 mL intramuscularly) if the patient has not received a booster within 10 years 1
• For contaminated wounds (all cat bites qualify), give tetanus toxoid if >5 years have elapsed since the last dose 1
• Prefer Tdap over Td if the patient has never previously received Tdap 1
• Patients without a documented primary vaccination series should complete the full series 1

Rabies Post-Exposure Prophylaxis

Rabies risk assessment is mandatory for all cat bites:

• Consult local health department immediately to determine rabies prevalence and need for prophylaxis 1
• Consider rabies prophylaxis for all feral and wild cat bites 1
• If the cat is healthy and available for observation, confine and observe for 10 days without initiating prophylaxis 1
• If the cat develops signs of rabies during observation, euthanize immediately and submit the head for testing while initiating prophylaxis 1
• If the cat is unavailable, stray, or cannot be observed, initiate rabies prophylaxis immediately 1

Complete rabies post-exposure prophylaxis regimen for previously unvaccinated persons:

• Human rabies immune globulin (HRIG) 20 IU/kg body weight on day 0, infiltrated around and into the wound(s) if anatomically feasible 1
• Rabies vaccine on days 0,3,7, and 14 at a site distant from HRIG administration 1
• Previously vaccinated persons receive only 2 doses of vaccine (days 0 and 3) without HRIG 1

Follow-Up and Monitoring

Close follow-up is essential due to high infection risk:

• Elevate the injured extremity using a sling (outpatients) or tubular stockinet with IV pole (inpatients) to reduce swelling 1
• Follow up within 24 hours by phone or office visit 1
• Monitor for signs of infection: increasing pain, redness, swelling, purulent drainage, or fever 1
• If infection progresses despite appropriate antimicrobial therapy, hospitalize immediately 1
• Consider a single initial dose of parenteral antimicrobial before starting oral therapy for high-risk wounds 1

Special Considerations for Hand Wounds

Cat bites to the hand require heightened vigilance:

• Hand wounds carry the highest infection risk and potential for serious complications 3, 4
• Pain disproportionate to injury near a bone or joint suggests periosteal or joint capsule penetration 1
• Complications include septic arthritis (requiring 4 weeks of antibiotics), osteomyelitis (requiring 6 weeks of antibiotics), tenosynovitis (requiring 3-4 weeks), abscess formation, and rarely bacteremia 1
• Non-infectious complications include nerve or tendon injury, compartment syndrome, post-traumatic arthritis, and functional impairment 1
• Prophylactic antibiotics are mandatory for all hand wounds 3, 4
• Intensive hand physiotherapy after a short period of immobilization is critical for optimal functional recovery 3

Common Pitfalls to Avoid

• Never close cat bite wounds (except facial wounds), as this dramatically increases infection risk 1
• Do not use antiseptic solutions for irrigation—they provide no benefit over saline and may damage tissue 1
• Do not perform aggressive debridement that enlarges the wound unnecessarily 1
• Never delay antibiotic prophylaxis for cat bites, particularly to the hand 3, 4
• Do not discharge patients without ensuring 24-hour follow-up is arranged 1
• Do not underestimate the infection risk—Pasteurella multocida is isolated in over 50% of cat bite wounds and can cause rapid, severe infection 4, 5