Would you consider administering a rabies vaccine (Rabies Immunoglobulin) to a patient with a cat bite in an unknown location, with unknown vaccination history and unknown medical history?

Rabies Post-Exposure Prophylaxis for Cat Bite

Direct Recommendation

For a cat bite with unknown vaccination status and unknown location, you should immediately initiate rabies post-exposure prophylaxis (PEP) with both rabies immune globulin (RIG) and rabies vaccine unless the cat is healthy, available, and can be confined for 10-day observation. 1, 2, 3

Decision Algorithm

If the Cat is Available and Appears Healthy:

• Confine and observe the cat for 10 days without initiating prophylaxis 4, 2
• The cat should be evaluated by a veterinarian at the first sign of illness during confinement 4
• Begin prophylaxis immediately if the animal develops any signs suggestive of rabies during the observation period 3
• If the cat remains healthy for 10 days, no prophylaxis is needed 2

If the Cat is Stray, Unwanted, or Unavailable for Observation:

• Initiate immediate rabies PEP without waiting 1, 2, 3
• The cat may be euthanized immediately and the head submitted for rabies examination 4
• Do not delay prophylaxis waiting for laboratory results if the animal is unavailable 1

Rabies PEP Regimen for Previously Unvaccinated Patients

Immediate Wound Care (Critical First Step):

• Thoroughly wash and flush the wound with soap and water for 15 minutes - this is the single most important intervention to reduce rabies transmission 1, 2, 3
• Irrigate with povidone-iodine solution after soap and water cleansing, as this is virucidal 1, 2
• Avoid suturing cat bite wounds when possible, as puncture wounds and cat bites have high infection risk 1

Rabies Immune Globulin (RIG):

• Administer 20 IU/kg body weight on day 0 1, 3
• Infiltrate the full dose around and into the wound if anatomically feasible 1, 3
• Inject any remaining volume intramuscularly at a site distant from the vaccine 1, 3
• Never administer RIG in the same syringe or same anatomical site as the vaccine 3

Rabies Vaccine:

• Administer simultaneously with RIG on day 0 at a different anatomical site 1, 3
• Complete the 5-dose series on days 0,3,7,14, and 28 1

Tetanus Prophylaxis:

• Assess tetanus immunization status and administer booster if indicated 1, 2, 3

Risk Assessment Factors

Higher Risk Scenarios (Favor Immediate Prophylaxis):

• Unprovoked attacks are more likely to indicate rabies than provoked attacks 2
• More cats than dogs are reported rabid in the United States, particularly in areas with raccoon rabies epizootics 2
• Unknown vaccination status of the cat increases risk 3

Critical Pitfalls to Avoid

1. Never delay rabies prophylaxis waiting for animal testing results if the cat is high-risk or unavailable 1
2. Never administer RIG after day 7 of the vaccine series - it interferes with active immunity 1
3. Never exceed the recommended RIG dose of 20 IU/kg - excess suppresses vaccine response 1, 3
4. Never delay wound cleansing - thorough wound cleansing alone markedly reduces rabies likelihood 2
5. Do not suture cat bite wounds - this increases infection risk from Pasteurella and other bacteria 1

When Prophylaxis Can Be Discontinued

• Only if laboratory testing (direct fluorescent antibody test) confirms the animal was not rabid 1, 3
• If the cat remains healthy throughout the entire 10-day observation period 2, 3

Timing Considerations

• RIG can be given up to day 7 if not administered initially, but never after day 7 1
• Do not withhold prophylaxis based on time elapsed since exposure unless clinical rabies is already present 1
• The incubation period in cats averages 2 months but can range from 2 weeks to several months or even years 5