What is the management for animal bites?

Animal Bite Management

Immediate Wound Care

All animal bite wounds require immediate copious irrigation with sterile normal saline or soap and water, followed by careful debridement of devitalized tissue—this is the single most effective measure for preventing both infection and rabies transmission. 1, 2, 3

• Use gentle irrigation technique with a 20-mL or larger syringe; avoid high-pressure irrigation as it may force bacteria deeper into tissue planes 1, 3
• Thoroughly explore wounds for tendon or nerve laceration, bone involvement, and foreign bodies 1, 3
• Avoid primary closure of most bite wounds as closure increases infection risk—the major exception is facial wounds, which should be closed after meticulous irrigation and prophylactic antibiotics for optimal cosmetic results 4, 1, 3
• Non-facial wounds may be approximated with Steri-Strips rather than sutured 5

Antibiotic Prophylaxis

Amoxicillin-clavulanate is the first-line antibiotic for animal bite prophylaxis and treatment, providing essential coverage against Pasteurella multocida, Staphylococcus, Streptococcus, and anaerobes. 4, 1, 3

Indications for 3-5 Days of Prophylactic Antibiotics:

• Hand, foot, face, or genital location wounds 1
• Deep wounds or puncture wounds 1, 6
• Wounds near joints or bones (risk of septic arthritis/osteomyelitis) 4, 1
• Immunocompromised, asplenic, or advanced liver disease patients 4, 1
• Wounds with significant edema 4
• Cat bites (higher infection risk than dog bites) 3

Antibiotic Regimens:

• Oral first-line: Amoxicillin-clavulanate 875/125 mg twice daily 4, 1
• Oral alternatives for penicillin allergy: Doxycycline 100 mg twice daily (excellent Pasteurella coverage) OR fluoroquinolone (ciprofloxacin, levofloxacin, moxifloxacin) plus metronidazole or clindamycin 5, 4, 1
• IV therapy: Ampicillin-sulbactam, piperacillin-tazobactam, second-generation cephalosporins (cefoxitin), or carbapenems 5, 4
• For established infections: 4 weeks for septic arthritis, 6 weeks for osteomyelitis 4

Tetanus Prophylaxis

• Administer tetanus toxoid (0.5 mL intramuscularly) if not vaccinated within the past 5-10 years 5, 1
• Tdap is preferred over Td if the patient has not previously received pertussis vaccination 4, 1

Rabies Risk Assessment and Prophylaxis

Dog and Cat Bites:

A healthy dog or cat that bites should be confined and observed daily for 10 days without administering rabies vaccine during the observation period. 7, 4, 2

• Do NOT start rabies prophylaxis if the animal can be observed 4, 2
• If the animal develops signs of rabies during observation, immediately euthanize and submit the head for brain examination 7, 4, 2
• Any stray or unwanted dog/cat that bites may be euthanized immediately and the head submitted for rabies examination 7, 4, 2
• If the animal cannot be confined or observed, initiate rabies post-exposure prophylaxis (PEP) immediately 4

Wild Animal Bites (Skunk, Bat, Fox, Coyote, Raccoon, Bobcat):

Regard as rabid unless proven negative by laboratory testing and initiate rabies PEP immediately. 2

Bat Exposure Special Consideration:

Rabies PEP should be considered for any physical contact with bats when bite or mucous membrane contact cannot be excluded, as bat bites may be less severe and go completely undetected. 2

Rabies Exposure Definition:

• Bite exposure: Any penetration of skin by teeth (bites to face and hands carry highest risk) 2
• Non-bite exposure: Scratches, abrasions, open wounds, or mucous membranes contaminated with saliva or brain tissue from a rabid animal 2
• NOT exposures: Casual contact (petting), contact with blood/urine/feces, or contact with dry material (virus is noninfectious when dry) 2
• Intact skin exposure to saliva does NOT warrant rabies PEP 4, 2

Rabies Post-Exposure Prophylaxis Regimen:

For previously unvaccinated persons, administer both rabies immune globulin (RIGH) and rabies vaccine on days 0,3,7, and 14. 1, 2, 3

• Rabies immune globulin should be infiltrated around the wound if anatomically feasible 2
• RIGH can be administered through day 7 after the first vaccine dose; beyond day 7, it is not indicated as antibody response is presumed 2
• Begin PEP as soon as possible after exposure (within 24 hours), but it remains indicated even with late presentation as incubation periods exceeding 1 year have been documented 4, 2
• Previously vaccinated persons with documented adequate antibody titer should receive vaccine only (no immune globulin) 2

Follow-Up Care

All patients must be evaluated within 24-72 hours to assess for signs of infection and wound healing progress. 5, 4, 1

• Hand wounds require particularly close monitoring due to highest infection risk and complication rates 4, 1
• Elevate injured extremities to reduce swelling and accelerate healing 5, 1
• If infection progresses despite appropriate antimicrobial therapy, hospitalization should be considered 4

High-Risk Scenarios Requiring Aggressive Management

Clenched-Fist Injuries (Human Bites):

Require expert hand evaluation for potential penetration into synovium, joint capsule, or bone—these carry the highest risk of septic arthritis and osteomyelitis. 5

Hand Wounds:

• Have the highest infection risk of all bite locations 4, 1
• May require 4-6 weeks of antibiotics if complications develop 4, 1
• Pain disproportionate to injury severity suggests periosteal penetration or deep infection 1

Immunocompromised/Asplenic/Advanced Liver Disease:

These patients are at risk for Capnocytophaga canimorsus sepsis from dog bites and require immediate broad-spectrum antibiotics. 1

Common Pitfalls to Avoid

• Do not close infected wounds or most non-facial bite wounds primarily 5, 1
• Do not administer rabies vaccine to the biting animal during the 10-day observation period 7, 4
• Do not delay rabies PEP for wild animal bites while awaiting animal capture 2
• Do not dismiss bat exposure without visible bite—treat any physical contact with bats as potential exposure 2
• Do not use high-pressure irrigation—this forces bacteria deeper 1