What is the recommended treatment for a dog bite, considering risk of infection, rabies, and tetanus?

Dog Bite Management

Immediately irrigate the wound thoroughly with soap and water for 15 minutes, administer prophylactic amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days for high-risk wounds, update tetanus if needed, and confine a healthy dog for 10-day observation rather than starting rabies prophylaxis. 1, 2

Immediate Wound Care

Copious irrigation with soap and water is the single most critical intervention that markedly reduces both rabies transmission and bacterial infection risk in animal studies. 3, 1 Use a 20-mL or larger syringe with sterile normal saline to mechanically flush out bacteria and debris. 2

• Debride devitalized tissue carefully, particularly for facial wounds where cosmetic outcomes matter. 2
• Avoid primary closure for most wounds—leave them open to drain or loosely approximate them at most. 3, 1 The only exception is facial wounds, which should receive copious irrigation, cautious debridement, preemptive antibiotics, and primary closure for optimal cosmetic results. 3, 1
• Never suture hand wounds or heavily contaminated wounds, as these carry significantly higher infection rates. 3, 1

Antibiotic Prophylaxis

Administer amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days for patients with: 1, 2

• Hand injuries
• Moderate-to-severe injuries
• Wounds that may have penetrated periosteum or joint capsule
• Immunocompromised status, asplenia, or advanced liver disease
• Edema of the affected area

Amoxicillin-clavulanate is first-line because dog bite wounds contain an average of 5 bacterial species, with 60% having mixed aerobic-anaerobic flora including Pasteurella (50% of cases), streptococci, staphylococci, Eikenella corrodens, and anaerobes (Fusobacterium, Bacteroides, Porphyromonas). 3, 1, 4

Alternative regimens for penicillin-allergic patients: 3

• Doxycycline (excellent Pasteurella coverage)
• Fluoroquinolone (ciprofloxacin or levofloxacin) plus metronidazole
• Moxifloxacin as monotherapy

For established infections requiring treatment (not prophylaxis): 1, 2

• Uncomplicated soft tissue infection: 7-10 days
• Septic arthritis: 4 weeks
• Osteomyelitis: 6 weeks

Tetanus Prophylaxis

Administer tetanus toxoid if the patient has not been vaccinated within 10 years. 3, 1, 2 For dirty wounds, give a booster if >5 years have elapsed; for clean wounds, if >10 years. 3

Tdap is preferred over Td if the patient has not previously received Tdap. 3, 1, 2

Rabies Risk Assessment and Management

For a healthy domestic dog that can be confined and observed: 3, 1, 2

• Do NOT initiate rabies vaccination immediately
• Confine and observe the dog daily for 10 days without administering rabies vaccine during this period
• A healthy dog that remains alive and healthy for 10 days would not have been shedding rabies virus at the time of the bite
• Only begin post-exposure prophylaxis if the dog develops signs of rabies during observation (behavioral changes, paralysis, excessive salivation, aggression, neurological signs)

If the dog develops signs suggestive of rabies: 3, 1

• Euthanize the animal immediately
• Submit the head under refrigeration for laboratory examination
• Simultaneously initiate rabies PEP in the exposed person

For stray, unwanted, or unavailable dogs: 3, 1

• The dog may be euthanized immediately and the head submitted for rabies examination
• Initiate rabies PEP immediately if the dog cannot be observed

Complete rabies PEP regimen (if indicated): 3, 1

• For previously unvaccinated individuals: Human rabies immune globulin (HRIG) 20 IU/kg on day 0 PLUS 4-dose vaccine series on days 0,3,7, and 14
• Infiltrate the full HRIG dose around and into the wound(s) if anatomically feasible, with remaining volume injected IM at a site distant from vaccine administration
• Never administer HRIG in the same syringe or at the same anatomical site as the vaccine
• For previously vaccinated individuals: Only 2 vaccine doses on days 0 and 3—do NOT give HRIG as it will suppress the anamnestic response

Critical pitfall: Do not withhold PEP while waiting for observation to complete if the dog is unavailable or shows any signs of illness. 1 Consult local health officials for regional rabies epidemiology assessment. 1

Mandatory Follow-Up

Schedule follow-up within 48-72 hours to assess for signs of infection (cellulitis, abscess formation, increasing pain, erythema, purulent drainage) and evaluate wound healing progress. 1, 2 Hand wounds and deep wounds near joints or bones require particularly close monitoring for septic arthritis, osteomyelitis, or neurovascular injury. 1