What is the first line treatment for a dog bite?

First-Line Treatment for Dog Bites

The first-line treatment for dog bites is immediate and thorough irrigation of the wound with copious amounts of water or sterile saline to minimize the risk of bacterial and rabies infections. 1

Initial Wound Management

1. Wound Cleansing:

   • Immediately clean the wound with soap and water or sterile normal saline 1
   • Use copious irrigation with a 20-mL or larger syringe or a 20-gauge catheter 2
   • Avoid iodine or antibiotic-containing solutions for initial cleaning 1
   • Remove superficial debris but avoid deep debridement unless necessary 1

2. Wound Assessment:

   • Examine for:
     • Tendon or bone involvement
     • Neurovascular function (pulses, sensation)
     • Range of movement of adjacent joints
     • Possible foreign bodies 3
   • Document the wound with photographs when appropriate 4

3. Tetanus Prophylaxis:

   • Administer tetanus toxoid (0.5 mL intramuscularly) if vaccination status is outdated or unknown 1

Antibiotic Therapy

Amoxicillin-clavulanate is the first-line prophylactic antibiotic for dog bites 5, 2, 3

• Alternative oral options for penicillin-allergic patients:

  • Doxycycline
  • Clindamycin plus a fluoroquinolone 1, 5

• Intravenous options (for severe infections):

  • β-lactam/β-lactamase combinations (ampicillin-sulbactam)
  • Piperacillin/tazobactam
  • Second-generation cephalosporins (cefoxitin)
  • Carbapenems 1

• Avoid first-generation cephalosporins, penicillinase-resistant penicillins, macrolides, and clindamycin alone due to poor activity against Pasteurella multocida 1

Wound Closure Considerations

• Primary closure may be considered for:

  • Facial wounds (cosmetic considerations)
  • Gaping wounds 2
  • Wounds seen within 8 hours of injury 1

• Avoid suturing:

  • Infected wounds
  • Wounds older than 8-12 hours
  • Hand wounds (higher infection risk) 1

Rabies Prophylaxis Assessment

For suspected rabid animal exposure:

1. Wound treatment as described above
2. Human Rabies Immune Globulin (HRIG) administered once at the beginning of prophylaxis
3. Rabies vaccine administered in a regimen of five doses on days 0,3,7,14, and 28 1

• Consult local health department regarding rabies risk in your area 1
• Bites that don't break the skin generally don't require rabies prophylaxis 3

Special Considerations

• Hand wounds require special attention as they have higher risk of complications including:

  • Septic arthritis
  • Osteomyelitis
  • Tenosynovitis 1

• Children most often present with bites to the head and neck region, requiring careful assessment 3

• Elevation of the injured body part, especially if swollen, accelerates healing 1

Common Pitfalls to Avoid

1. Inadequate irrigation - Thorough wound cleansing alone can markedly reduce infection risk 1

2. Inappropriate antibiotic selection - First-generation cephalosporins and penicillinase-resistant penicillins have poor activity against Pasteurella multocida 1

3. Delayed treatment - Patients presenting >8-12 hours after injury typically have established infection 1

4. Overlooking deep structure damage - Always assess for tendon, nerve, or bone involvement 2

5. Neglecting tetanus or rabies prophylaxis - These should be considered for all animal bites 2

Dog bites are polymicrobial infections commonly involving Pasteurella, streptococci, staphylococci, and anaerobes such as Fusobacterium, Bacteroides, and Porphyromonas species 5. This bacterial profile guides the choice of broad-spectrum antibiotics that cover both aerobic and anaerobic organisms.