Is a rabies vaccine on day 28 necessary for post-exposure prophylaxis (PEP) after a bite from a giant swamp rat?

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Last updated: January 12, 2026View editorial policy

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Rabies Vaccination After Giant Swamp Rat Bite: Day 28 Dose Not Necessary

You do not need rabies post-exposure prophylaxis (PEP) at all for a giant swamp rat bite, including the day 28 dose, because rodents are not rabies reservoirs and have never been documented to transmit rabies to humans. 1, 2

Why Rodents Don't Require Rabies PEP

  • Small rodents including rats are almost never infected with rabies and have not been documented to transmit rabies to humans in any reported case 1, 2

  • The CDC's Advisory Committee on Immunization Practices (ACIP) explicitly states that "rodents are not reservoirs of rabies virus" and that small rodents (including rats, mice, squirrels, chipmunks, hamsters, guinea pigs, and gerbils) "are rarely infected with rabies and have not been known to transmit rabies to humans" 1

  • During 1990-1996 surveillance in areas with endemic raccoon rabies, rats were not significantly represented in rabies cases among rodents—woodchucks accounted for 93% of the 371 rodent rabies cases reported to CDC 1, 2

What You Should Do Instead

  • Immediate wound care is critical: Thoroughly wash the bite wound with soap and water for 15 minutes, then apply a virucidal agent such as povidone-iodine solution 2, 1

  • Assess for bacterial infection risk: Rat bites carry a significant risk of bacterial infections, particularly rat bite fever, which is a more important concern than rabies 2

  • Update tetanus prophylaxis if needed and consider prophylactic antibiotics for bacterial infection control 2, 1

  • Consult local public health authorities before initiating any rabies PEP for rodent bites, as recommended by ACIP 1

Important Caveat

  • If the rat's behavior was highly unusual or abnormal, consultation with public health authorities is still warranted, though rabies transmission remains extremely unlikely even in these circumstances 2

  • The only rodent species that has shown any meaningful rabies prevalence is the woodchuck in raccoon rabies endemic areas, but even this represents a rare exception 1

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Rabies Post-Exposure Prophylaxis for Rodent Bites

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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