What lab work is needed for a patient with a facial dog bite and unknown vaccine status?

Laboratory Work Required for Facial Dog Bite with Unknown Vaccine Status

For a patient with a facial dog bite and unknown vaccine status, essential laboratory work includes tetanus antibody titers, complete blood count (CBC), and rabies virus testing of the dog if available, with immediate initiation of rabies post-exposure prophylaxis if the dog cannot be observed for 10 days. 1, 2

Initial Assessment and Laboratory Tests

Essential Laboratory Tests:

• Tetanus antibody titers or verification of tetanus immunization status
• Complete blood count (CBC) to assess for infection and baseline status
• Basic metabolic panel to assess overall health status before potential treatments
• Blood type and screen if significant blood loss or potential for surgical intervention

Dog-Related Testing:

• Rabies testing of the dog if euthanized or deceased
• Dog observation documentation if the dog is available for 10-day monitoring

Rabies Risk Assessment and Management

Determining Need for Rabies Prophylaxis:

• Dog vaccination status: Unknown vaccination status increases risk 1
• Dog availability for observation: If unavailable, immediate prophylaxis is indicated 2
• Bite circumstances: Unprovoked bites carry higher rabies risk than provoked bites 2
• Facial location: Facial bites warrant more aggressive management due to shorter incubation period and proximity to brain 1

Testing Algorithm:

1. If dog is available and appears healthy:

   • Observe for 10 days
   • No immediate rabies testing needed unless dog develops symptoms 2

2. If dog is unavailable, stray, or showing signs of illness:

   • Immediate rabies post-exposure prophylaxis indicated
   • No waiting for laboratory confirmation 1, 2

3. If dog is euthanized:

   • Direct fluorescent antibody test on brain tissue is the gold standard 2, 3

Infection Risk Assessment

Bacterial Culture and Sensitivity:

• Wound culture if signs of infection are present
• Blood cultures if systemic infection is suspected

Monitoring for Infection:

• C-reactive protein and erythrocyte sedimentation rate to monitor inflammatory response
• Follow-up CBC to assess response to antibiotics if prescribed 4

Special Considerations for Facial Bites

• Facial bites require more aggressive management due to:
  • Cosmetic concerns
  • Rich vascular supply increasing infection risk
  • Proximity to brain for rabies transmission 1, 5
  • Higher risk of complications including nerve damage

Common Pitfalls to Avoid

1. Delaying rabies prophylaxis while waiting for dog testing results when the dog is unavailable for observation 2
2. Overlooking tetanus status in the urgency to address rabies risk 1
3. Failing to document dog information including owner contact details, vaccination history, and behavior at time of bite
4. Not reporting the bite to local public health authorities, which is required in most jurisdictions 1
5. Underestimating the severity of facial bites, which can lead to life-threatening complications 5

Follow-up Laboratory Testing

• Rabies antibody titers after completion of vaccination series to confirm adequate immune response in high-risk cases
• Follow-up CBC and inflammatory markers if infection was present
• Wound healing assessment with documentation of cosmetic and functional outcomes

Remember that facial dog bites represent a medical emergency requiring prompt assessment and management, with laboratory testing focused on preventing rabies, tetanus, and bacterial infections while optimizing cosmetic and functional outcomes.