What is the appropriate treatment for a patient with a dog bite, assuming they are up-to-date on their tetanus vaccination and have no known allergies or immunocompromised status?

Dog Bite Management

For a dog bite in an immunocompetent patient with up-to-date tetanus vaccination, immediately irrigate the wound copiously with sterile normal saline, consider antibiotic prophylaxis with amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days (especially for high-risk wounds), avoid primary closure except for facial wounds, and assess rabies risk based on the dog's observability. 1, 2, 3

Immediate Wound Management

Thorough wound cleansing is the single most critical intervention to prevent infection and potential rabies transmission. 3

• Immediately wash the wound with soap and water for approximately 15 minutes 3, 4
• Follow with copious irrigation using sterile normal saline through a 20-mL or larger syringe or 20-gauge catheter 5, 6
• Consider adding povidone-iodine solution to the irrigation for additional virucidal effect 3
• Carefully explore the wound for tendon or bone involvement, periosteal penetration, joint capsule penetration, and foreign bodies 3, 4

Antibiotic Prophylaxis Decision

Amoxicillin-clavulanate 875/125 mg twice daily for 3-5 days is the first-line antibiotic choice. 1, 2, 3

High-Risk Wounds Requiring Prophylaxis:

• Hand injuries (higher infection risk) 3, 6
• Wounds with crushed tissue 3
• Puncture wounds 2, 6
• Wounds potentially penetrating periosteum or joint capsule 2
• Wounds with edema of the affected area 2
• Moderate to severe injuries 2
• Delayed presentation (>8 hours after injury) 3

Why Amoxicillin-Clavulanate:

• Covers Pasteurella multocida (found in 50% of dog bites) 3
• Provides coverage against staphylococci, streptococci, Eikenella corrodens, and multiple anaerobes including Fusobacterium, Prevotella, and Porphyromonas species 1

Alternative Regimens for β-Lactam Allergy:

• Doxycycline 100 mg twice daily (excellent activity against Pasteurella, staphylococci, and anaerobes) 1
• Fluoroquinolone (ciprofloxacin or levofloxacin) plus metronidazole 1
• Moxifloxacin as a single agent 1

Critical Pitfall: Do not use first-generation cephalosporins, macrolides, clindamycin, or aminoglycosides alone, as Eikenella corrodens is resistant to these agents. 1, 3

Wound Closure Guidelines

Primary closure is generally NOT recommended for dog bite wounds, with the important exception of facial wounds. 1, 2

Facial Wounds:

• May be closed primarily after copious irrigation, cautious debridement, and initiation of preemptive antibiotics for optimal cosmetic outcomes 1, 2, 3

Non-Facial Wounds:

• Should not be closed primarily 1, 3
• May be approximated (edges brought together without full closure) 1, 2
• Hand wounds carry particularly high infection risk when closed 1, 3

Critical Pitfall: Closing non-facial wounds, especially hand wounds and puncture wounds, significantly increases infection risk. 1, 3

Tetanus Prophylaxis

Since the patient is up-to-date on tetanus vaccination (within 10 years), no tetanus prophylaxis is needed for this clean wound. 1

• For reference: Tetanus toxoid would be indicated if >10 years since last dose for clean wounds, or >5 years for dirty wounds 1
• Tdap is preferred over Td if the patient has never received Tdap 1

Rabies Risk Assessment

If the dog is healthy and domestic, confine and observe for 10 days without initiating rabies prophylaxis. 2, 3

Observation Protocol:

• A healthy domestic dog that remains alive and healthy for 10 days after biting would not have been shedding rabies virus at the time of the bite 2
• Do not administer rabies vaccine during the observation period 2
• Only initiate post-exposure prophylaxis if the dog develops signs of rabies (behavioral changes, paralysis, excessive salivation, aggression, neurological signs) during observation 2

Immediate Rabies PEP Indicated If:

• The dog is stray, unwanted, or cannot be observed 2, 3
• The dog shows any signs of illness during observation 2

Complete PEP Regimen (if indicated):

• Human rabies immune globulin (HRIG) 20 IU/kg infiltrated around/into the wound on day 0 2, 4
• Rabies vaccine on days 0,3,7, and 14 2, 3, 4
• Never administer HRIG in the same syringe or site as the vaccine 2

Critical Pitfall: Consult local health officials for regional rabies epidemiology, as risk varies significantly by location. 2

Follow-Up Care

All patients must be seen within 48-72 hours to assess for signs of infection and evaluate wound healing. 2, 3, 4

Signs of Infection to Monitor:

• Cellulitis 2, 4
• Abscess formation 2, 4
• Septic arthritis 2, 4
• Osteomyelitis 2, 4
• Tendonitis 2, 4
• Bacteremia or sepsis (rare) 3, 4

Special Attention for Hand Wounds:

• Higher risk of infection and functional complications 2
• Deep wounds near joints or bones require evaluation for periosteal or joint capsule penetration 2, 4

Critical Pitfall: If infection progresses despite appropriate antimicrobial therapy, hospitalization should be considered. 2