What is the appropriate treatment for a red dog scratch?

Treatment for a Red Dog Scratch

For a red dog scratch, provide thorough wound care with cleaning and irrigation, ensure tetanus prophylaxis is up to date, and consider prophylactic antibiotics with amoxicillin-clavulanate 875/125 mg twice daily only if the wound is high-risk (puncture-type, on hand/face/foot, or in immunocompromised patients). 1

Risk Stratification

The decision to use antibiotics hinges on wound characteristics and patient factors:

Low-Risk Wounds (Antibiotics Generally NOT Needed)

• Superficial scratches without puncture
• Not involving hand, face, or foot
• Immunocompetent patient
• Presenting within 12-24 hours
• Infection rate only 2.6% without antibiotics 2

High-Risk Wounds (Strongly Consider Antibiotics)

• Puncture-type wounds (4.1 times higher infection risk) 2
• Hand, face, or foot involvement 1
• Wounds requiring closure (3.1 times higher infection risk) 2
• Immunocompromised patients
• Delayed presentation (>12-24 hours)

Antibiotic Selection

First-line: Amoxicillin-clavulanate 875/125 mg twice daily 1

This covers the polymicrobial flora from dog scratches/bites, including:

• Pasteurella multocida (common in dog/cat wounds)
• Streptococcus species (including S. canis, a zoonotic pathogen from dogs) 3
• Staphylococcus aureus
• Anaerobes

Alternative Regimens (if penicillin allergy):

• Doxycycline 100 mg twice daily - excellent against Pasteurella, though some streptococci resistant 1
• Moxifloxacin 400 mg daily - monotherapy with anaerobic coverage 1
• Ciprofloxacin 500-750 mg twice daily PLUS metronidazole - covers aerobes and anaerobes 1

Essential Wound Management

1. Irrigate thoroughly with warm water or normal saline 4
2. Remove devitalized tissue and foreign bodies 4
3. Assess neurovascular status - check pulses, sensation, range of motion 4
4. Avoid primary closure in high-risk wounds (puncture wounds, hand injuries) - closure increases infection risk 3-fold 2

Tetanus Prophylaxis

Administer tetanus toxoid if not vaccinated within 10 years - preferably Tdap over Td if not previously given 1

Critical Pitfalls to Avoid

• Don't dismiss simple scratches in immunocompromised patients - they warrant prophylactic antibiotics regardless of appearance 1
• Don't close puncture wounds - this dramatically increases infection risk 2
• Don't use clindamycin alone - it misses Pasteurella multocida, a key dog wound pathogen 1
• Don't forget cat scratch disease - if lymphadenopathy develops 3 weeks later, treat with azithromycin 500 mg day 1, then 250 mg for 4 days 1

When to Escalate

Watch for signs requiring IV antibiotics or surgical consultation:

• Rapidly spreading erythema (necrotizing infection possible with Group A Streptococcus) 5
• Systemic symptoms (fever, hypotension)
• Deep tissue involvement
• Joint or bone involvement 6
• Failure to improve on oral antibiotics within 48-72 hours

The evidence shows that while overall infection rates from dog bites/scratches are relatively low (5.2% in recent studies 2, 16% in meta-analysis 1), targeted prophylaxis for high-risk wounds provides meaningful benefit without overtreating low-risk injuries.