What are the guidelines for categorizing and managing dog bites?

Guidelines for Categorizing and Managing Dog Bites

Dog bites should be categorized based on wound characteristics, infection risk, and managed with thorough wound cleansing, appropriate antibiotic therapy (amoxicillin-clavulanate as first-line), and consideration for tetanus and rabies prophylaxis. 1

Categorization of Dog Bites

Dog bites can be categorized based on several key factors:

1. Wound Type

• Nonpurulent wounds (30% of dog bites) 1
• Purulent wounds (58% of dog bites) 1
• Abscesses (12% of dog bites) 1

2. Risk Factors for Infection

• High-risk wounds:

  • Hand/finger wounds
  • Puncture wounds (especially deep)
  • Wounds with crush injury
  • Wounds presenting >8 hours after injury
  • Wounds in immunocompromised patients
  • Wounds near joints or tendons 1, 2

• Low-risk wounds:

  • Superficial wounds
  • Wounds presenting <8 hours after injury
  • Wounds in healthy, immunocompetent patients 1

Management Algorithm

Step 1: Initial Assessment

• Examine for neurovascular function (pulses, sensation)
• Check range of motion of adjacent joints
• Document wound characteristics (size, depth, location)
• Assess for foreign bodies or damage to underlying structures 2

Step 2: Wound Cleansing

• Irrigate thoroughly with sterile normal saline (not under pressure)
• Use 20-mL or larger syringe for irrigation
• Remove foreign bodies and debride necrotic tissue
• Do not use iodine or antibiotic-containing solutions 1, 2

Step 3: Wound Closure Decision

• Primary closure may be considered for:

  • Facial wounds (cosmetic concerns)
  • Fresh wounds (<8 hours)
  • Low infection risk wounds 2, 3

• Avoid primary closure for:

  • Infected wounds
  • Puncture wounds
  • Wounds >24 hours old
  • Hand wounds with high infection risk 1

Step 4: Antibiotic Therapy

Prophylactic Antibiotics

• Indications for prophylactic antibiotics:

  • Deep wounds
  • Hand/foot wounds
  • Wounds near joints
  • Facial or genital wounds
  • Immunocompromised patients
  • Wounds with crush injury 1

• First-line oral antibiotic:

  • Amoxicillin-clavulanate: 875/125 mg twice daily for 5-7 days 1, 2

• Alternative oral options (for penicillin allergy):

  • Doxycycline: 100 mg twice daily 4
  • Clindamycin (300-450 mg three times daily) plus TMP-SMX or fluoroquinolone 4

Established Infection Treatment

• For mild to moderate infections:

  • Same oral antibiotics as prophylaxis but for 7-10 days 1

• For severe infections (IV therapy):

  • Ampicillin-sulbactam, piperacillin-tazobactam, or a carbapenem 1
  • Consider MRSA coverage if suspected 4

Step 5: Tetanus Prophylaxis

• Administer tetanus toxoid if not vaccinated within 5 years 5
• For patients with unknown or incomplete tetanus vaccination history, administer tetanus immune globulin plus tetanus toxoid 2

Step 6: Rabies Assessment

• Evaluate need for rabies post-exposure prophylaxis
• Consider rabies immune globulin at presentation and vaccination on days 0,3,7, and 14 5
• Bites that don't break the skin generally don't require rabies prophylaxis 2

Special Considerations

Complications to Monitor

• Septic arthritis
• Osteomyelitis
• Subcutaneous abscess formation
• Tendonitis
• Bacteremia (rare) 1

Common Pathogens

• Pasteurella species (found in 50% of dog bite wounds)
• Staphylococci and streptococci (found in 40% of bites)
• Capnocytophaga canimorsus (especially dangerous in asplenic or hepatic disease patients)
• Anaerobes (Bacteroides, Fusobacterium, Porphyromonas species) 1

Follow-up

• Reassess within 48-72 hours for signs of infection
• Immediate return if increasing pain, redness, swelling, or systemic symptoms develop 2

Pitfalls to Avoid

• Don't use pressure irrigation as it may spread bacteria into deeper tissues 1
• Don't delay antibiotic therapy for high-risk wounds or immunocompromised patients 1
• Don't use first-generation cephalosporins alone as they have poor activity against Pasteurella multocida 1
• Don't forget to report animal bites as required by local laws 5

By following this structured approach to categorizing and managing dog bites, clinicians can optimize outcomes and minimize complications for patients with these common injuries.