What are the current guidelines for animal bite treatment?

Animal Bite Treatment Guidelines

Immediate Wound Management

All animal bite wounds should be thoroughly irrigated with copious amounts of running tap water or sterile saline until no visible debris remains, and any wound contaminated with animal saliva must be evaluated at a medical facility as soon as possible. 1

• Irrigate using a 20-mL or larger syringe with normal saline to achieve adequate pressure for removing bacterial contamination 2
• Running tap water is as effective as sterile saline and superior to antiseptic agents like povidone-iodine for irrigation 1
• Explore the wound for tendon involvement, bone penetration, and foreign bodies 2
• Avoid aggressive debridement that causes additional tissue damage 3

Wound Closure Decisions

• Do not close infected wounds or wounds presenting >8 hours after injury 4
• Facial wounds are an exception and may be closed primarily after meticulous irrigation and prophylactic antibiotics 4
• For clean, early-presenting wounds (<8 hours), consider approximation with Steri-Strips rather than sutures 4
• Most bite wounds should be left open to heal by secondary intention 3

Antibiotic Prophylaxis and Treatment

Amoxicillin-clavulanate is the first-line antibiotic for both prophylaxis and treatment of dog and cat bites. 1, 4

High-Risk Wounds Requiring Antibiotics

Prophylactic antibiotics are indicated for: 1, 2

• Hand wounds (highest infection risk)
• Puncture wounds (especially cat bites)
• Cat bites in any location (75% harbor Pasteurella multocida)
• Wounds presenting >8 hours after injury
• Immunocompromised patients
• Wounds with crush injury or devitalized tissue

Oral Antibiotic Options

First-line: Amoxicillin-clavulanate 1, 4

Penicillin-allergic patients: 1, 4

• Doxycycline, OR
• Penicillin VK plus dicloxacillin, OR
• Fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) PLUS metronidazole or clindamycin

Avoid these agents (poor activity against P. multocida): 1

• First-generation cephalosporins (cephalexin)
• Penicillinase-resistant penicillins alone (dicloxacillin)
• Macrolides (erythromycin)
• Clindamycin monotherapy

Intravenous Antibiotic Options

For severe infections requiring hospitalization: 1, 4

• First-line: Ampicillin-sulbactam or piperacillin-tazobactam
• Alternatives: Cefoxitin (second-generation cephalosporin) or carbapenems (ertapenem, imipenem, meropenem)

Treatment Duration

• Standard infections: 5-7 days 1
• Osteomyelitis: 4-6 weeks 4
• Septic arthritis: 3-4 weeks 4

Tetanus Prophylaxis

Administer tetanus toxoid (0.5 mL intramuscularly) if vaccination status is outdated or unknown. 4, 3

• Give booster if >10 years since last dose for clean wounds 3
• Give booster if >5 years since last dose for contaminated wounds 3

Rabies Risk Assessment and Prophylaxis

When to Consider Rabies Prophylaxis

Rabies risk depends on: 2, 5

• Species of animal (carnivorous wild animals, bats, unvaccinated domestic animals are highest risk)
• Geographic location
• Circumstances of attack (unprovoked attacks are higher risk)
• Vaccination status of domestic animal

Rabies Prophylaxis Protocol

For previously unvaccinated persons with suspected rabies exposure: 4, 3

• Rabies immune globulin (HRIG) on day 0
• Rabies vaccine (HDCV or PCECV) on days 0,3,7,14, and 28
• Administer vaccine in deltoid area for adults, anterolateral thigh for children
• Never use gluteal area (causes vaccine failure due to lower antibody titers) 3

Begin vaccination immediately without waiting for animal observation results. 3

Special Considerations

Cat Bites

• Higher infection rate than dog bites (50% vs 15-20%) 1
• 75% harbor P. multocida vs 50% in dog bites 1
• Greater risk of osteomyelitis and septic arthritis due to deep puncture nature 1
• Lower threshold for antibiotic prophylaxis 2

Clenched-Fist Injuries (Human Bites)

These require immediate expert hand surgery evaluation due to high risk of joint capsule penetration, septic arthritis, and osteomyelitis. 4

• Same antibiotic regimen as animal bites (amoxicillin-clavulanate first-line) 4
• Higher risk of Staphylococcus and Streptococcus species 1

Hand Wounds

• Highest risk location for infection and complications 1, 2
• Always warrant antibiotic prophylaxis 2
• Require close follow-up within 24 hours 4

Wound Care and Follow-Up

• Cover clean wounds with occlusive dressing to promote healing 1
• Elevate injured extremity, especially if swollen 1, 4
• Follow up within 24 hours by phone or office visit 4
• Signs requiring immediate re-evaluation: redness, swelling, foul-smelling drainage, increased pain, or fever 1

Critical Pitfalls to Avoid

• Do not use antiseptic solutions for irrigation (no benefit over water/saline) 1
• Do not close wounds >8 hours old or contaminated wounds 4
• Do not delay medical evaluation for animal saliva-contaminated wounds 1
• Do not use antibiotics with poor Pasteurella coverage (cephalexin, macrolides, clindamycin alone) 1
• Do not administer rabies vaccine in gluteal area 3
• Do not wait for animal observation results before starting rabies prophylaxis 3