What is the proper treatment for a dog bite?

Dog Bite Treatment

For dog bite wounds, immediately irrigate thoroughly with soap and water for 15 minutes, then prescribe amoxicillin-clavulanate 875/125 mg twice daily for prophylaxis (especially for high-risk wounds), update tetanus if needed, and assess rabies risk based on the animal's vaccination status and ability to observe for 10 days. 1, 2

Immediate Wound Management

All dog bite wounds require aggressive irrigation as the single most critical intervention to prevent infection and rabies transmission. 2

• Wash the wound immediately with soap and water for approximately 15 minutes, followed by copious irrigation with sterile normal saline or dilute povidone-iodine solution. 3, 2, 4
• Use a 20-mL or larger syringe (or 20-gauge catheter attached to syringe) for gentle but thorough irrigation to adequately cleanse without damaging tissue. 2, 5
• Perform careful debridement of devitalized tissue while preserving viable tissue, especially for facial wounds. 2
• Explore the wound for tendon, bone, or joint involvement - pain disproportionate to injury severity near a bone or joint suggests periosteal penetration and indicates higher complication risk. 1, 5

Wound Closure Decisions

• Facial lacerations should receive primary closure after thorough cleaning due to rich vascular supply and cosmetic importance, preferably by a plastic surgeon if available. 1, 2
• Non-facial wounds, especially hand wounds, should generally NOT be closed primarily - instead approximate margins with Steri-Strips and allow delayed primary or secondary closure. 1
• Infected wounds should never be closed. 1
• Early suturing (<8 hours after injury) remains controversial for non-facial wounds. 1

Antibiotic Prophylaxis

Amoxicillin-clavulanate 875/125 mg twice daily is the first-line antibiotic for dog bite wounds, providing essential coverage against Pasteurella multocida (present in 50% of dog bites), staphylococci, streptococci, and anaerobes. 1, 2

High-Risk Wounds Requiring Prophylaxis

• All hand or foot wounds (hand wounds are particularly serious due to proximity to tendons, joints, and bones). 1, 2
• All facial wounds. 2
• Puncture wounds. 5
• Wounds presenting >8-12 hours after injury. 1
• Immunocompromised patients, including those with asplenia or advanced liver disease (at higher risk for Capnocytophaga canimorsus bacteremia and fatal sepsis). 1, 2

Alternative Antibiotic Regimens

• For penicillin-allergic patients: doxycycline OR a fluoroquinolone (ciprofloxacin, levofloxacin, moxifloxacin) plus metronidazole or clindamycin for anaerobic coverage. 1, 3
• Avoid these agents as they have poor activity against P. multocida: first-generation cephalosporins (cephalexin), penicillinase-resistant penicillins (dicloxacillin), macrolides (erythromycin), and clindamycin alone. 1, 3

Intravenous Options for Severe Infections

For hospitalized patients or severe infections: ampicillin-sulbactam, piperacillin-tazobactam, cefoxitin, or carbapenems (ertapenem, imipenem, meropenem). 1, 3

Tetanus Prophylaxis

Administer tetanus toxoid (0.5 mL intramuscularly) if vaccination is not current within the past 5 years or if immunization status is unknown. 1, 2, 4

Rabies Assessment and Prophylaxis

The decision for rabies prophylaxis depends on three critical factors: 4

1. Animal Type and Vaccination Status

• If the dog is healthy, domestic, and available: confine and observe for 10 days without starting rabies prophylaxis. 2, 4
• Begin prophylaxis immediately at first sign of rabies during the observation period. 4
• If the dog cannot be observed, is stray, shows concerning behavior, or escapes: initiate rabies post-exposure prophylaxis immediately. 2, 4

2. Circumstances of the Bite

• Unprovoked attacks are more likely to indicate rabies than provoked attacks (e.g., attempting to feed or handle the animal). 4
• Consult local or state health department to determine best course based on regional rabies epidemiology. 4

3. Rabies Post-Exposure Prophylaxis Protocol

For previously unvaccinated persons exposed to suspected rabid animal: 4, 5

• Administer rabies immune globulin (RIG) at presentation (infiltrate around wound if anatomically feasible, give remainder intramuscularly at distant site). 4
• Administer rabies vaccine series on days 0,3,7, and 14 (some protocols include day 28). 2, 4, 5
• For previously vaccinated persons: vaccine alone (no RIG needed), given on days 0 and 3. 4

Bacteriology and Infection Risk

Dog bite wounds yield an average of 5 bacterial species per wound, with approximately 60% containing mixed aerobic and anaerobic bacteria: 1

• Pasteurella multocida: 50% of dog bites. 1
• Staphylococci and streptococci: ~40% of bites. 1
• Capnocytophaga canimorsus: can cause fatal sepsis, especially in asplenic or liver disease patients. 1
• Anaerobes: Bacteroides species, fusobacteria, Porphyromonas species, Prevotella heparinolytica, peptostreptococci (present in 50% of dog bites). 1

Follow-Up and Complications Monitoring

• Elevate the injured body part during the first few days after injury to accelerate healing. 1
• All patients must be seen within 24-48 hours (by phone or office visit) to assess for infection signs. 1, 2
• Monitor for increasing pain, redness, swelling, or purulent discharge. 2

Serious Complications Requiring Prolonged Therapy

• Septic arthritis: requires 3-4 weeks of antibiotics. 1
• Osteomyelitis: requires 4-6 weeks of antibiotics. 1
• Other complications include subcutaneous abscess, tendonitis, bacteremia, nerve or tendon injury, compartment syndromes, and fractures. 1, 2

Common Pitfalls to Avoid

• Do not close hand wounds or infected wounds primarily - this significantly increases infection risk. 1
• Do not use inadequate irrigation - thorough 15-minute washing is the most important intervention. 3, 2, 4
• Do not prescribe cephalexin, dicloxacillin, or macrolides alone - these lack adequate Pasteurella coverage. 1, 3
• Do not delay rabies prophylaxis if the dog cannot be observed or shows concerning behavior. 2, 4
• Do not underestimate hand wounds - these have higher complication rates and always warrant prophylactic antibiotics. 1, 2