What is the treatment for post-exposure dog bites in the United States (US)?

Post-Exposure Management of Dog Bites in the United States

For dog bites in the US, immediately wash the wound thoroughly with soap and water for 15 minutes, assess the need for rabies post-exposure prophylaxis based on whether the dog can be observed for 10 days, administer amoxicillin-clavulanate for prophylaxis (especially for hand wounds or wounds near bones/tendons), and ensure tetanus immunization is current. 1, 2, 3

Immediate Wound Care (First and Most Critical Step)

• Wash all bite wounds immediately and thoroughly with soap and water for approximately 15 minutes - this is the single most effective measure for reducing both infection risk and potential rabies transmission 1, 3
• After soap and water cleansing, irrigate with povidone-iodine solution 3
• Examine wounds carefully for tendon or bone involvement, joint penetration, or pain disproportionate to the injury near bones or joints 1
• Consider wound closure for facial wounds if seen early and properly cleaned, balancing cosmetic factors against infection risk 1

Rabies Post-Exposure Prophylaxis Decision Algorithm

Step 1: Determine if the Dog Can Be Observed

For healthy domestic dogs in the US, confine and observe the animal for 10 days - dogs that remain healthy during this period were not shedding rabies virus at the time of the bite 4, 2, 3

• If the dog remains healthy for the full 10 days, no rabies prophylaxis is needed 4, 3
• The observation period must be prospective (the dog must be alive and healthy throughout the entire 10 days) 2

Step 2: Initiate Immediate Rabies PEP If:

• The dog is stray or unwanted - kill immediately and submit the head for rabies testing 4, 3
• The dog cannot be confined for observation 3
• The dog dies or develops illness before completing the 10-day observation period - start PEP immediately 2
• The dog shows signs suggestive of rabies during observation - humanely kill and test the brain 4

Step 3: Complete Rabies PEP Regimen (If Indicated)

For individuals never previously vaccinated against rabies:

• Human Rabies Immune Globulin (HRIG): 20 IU/kg body weight given once on day 0 - infiltrate as much as possible around the wound, inject remaining volume intramuscularly at a site distant from vaccine 4, 2, 3
• Rabies vaccine: 5 doses on days 0,3,7,14, and 28 4, 2, 3
• Administer vaccine intramuscularly in the deltoid area for adults; anterolateral thigh is acceptable for children 4
• Never use the gluteal area - this results in lower neutralizing antibody titers 4

For individuals with documented prior complete rabies vaccination:

• Vaccine only (no HRIG): 2 doses on days 0 and 3 3

Critical Timing Considerations:

• Begin treatment within 24 hours when possible 4
• PEP should be administered regardless of delay, even if months have passed, as long as the person shows no clinical signs of rabies 2
• Rabies incubation periods exceeding 1 year have been documented 2
• PEP is a "medical urgency, not a medical emergency" 2

Antibiotic Prophylaxis

Administer amoxicillin-clavulanate as first-line prophylactic antibiotic 1

• Antibiotic prophylaxis is particularly important for:
  • Hand wounds 1
  • Wounds over tendons or bones 1
  • Immunocompromised patients 1

For penicillin-allergic patients, alternatives include:

• Doxycycline 1
• Fluoroquinolone plus an agent active against anaerobes 1
• Clindamycin plus a fluoroquinolone 1

Tetanus Prophylaxis

• Assess tetanus immunization status and administer tetanus prophylaxis as indicated 1, 3
• Give tetanus toxoid to patients with unknown or incomplete tetanus immunization 1

Factors Influencing Rabies Risk Assessment

Vaccination Status of the Dog:

• A fully vaccinated dog is unlikely to become infected with rabies, though rare cases have been reported 4, 3
• In a 1988 nationwide study, vaccine failures only occurred in animals receiving single doses; no failures occurred with two or more vaccinations 4

Circumstances of the Bite:

• Unprovoked attacks are more likely to indicate rabies than provoked attacks 4, 3
• Bites inflicted while attempting to feed or handle an apparently healthy animal should be regarded as provoked 4

Geographic Considerations:

• In the continental US, canine rabies is reported most commonly along the US-Mexico border and sporadically in areas with enzootic wildlife rabies 4
• More cats than dogs were reported rabid in the US during the 1980s-2000s, primarily due to lower vaccination rates and exposure to wildlife reservoirs 4, 3

Potential Complications to Monitor

• Infectious complications include septic arthritis, osteomyelitis, subcutaneous abscess, tendonitis, and bacteremia 1
• Causative organisms include Pasteurella species, Staphylococci, and anaerobes 1
• Capnocytophaga canimorsus can cause fatal sepsis, especially in patients with asplenia or underlying hepatic disease 1

Critical Pitfalls to Avoid

• Never delay wound cleansing - this is your first and most important intervention 3
• Do not initiate unnecessary PEP for healthy domestic dogs that can be observed for 10 days 3
• Do not exceed the recommended HRIG dose - excess HRIG can suppress active antibody production 3
• Do not administer HRIG and vaccine at the same anatomical site 3
• Do not assume vaccination status alone eliminates risk, though vaccinated dogs rarely develop rabies 3
• Consult local or state health departments for region-specific rabies epidemiology and guidance 3
• If the dog tests negative for rabies by laboratory testing, discontinue PEP immediately 3