Tetanus Prophylaxis for Cat Scratches
A tetanus toxoid-containing vaccine is indicated for cat scratches if more than 5 years have passed since the last tetanus toxoid-containing vaccine dose, as cat scratches are considered "other wounds" that may be contaminated with dirt, feces, soil, or saliva. 1
Classification of Cat Scratches and Tetanus Risk
- Cat scratches are classified as "other wounds" (non-clean wounds) that may be contaminated with dirt, feces, soil, or saliva, similar to puncture wounds and avulsions 1
- Cats are coprophagic (feces-eating) animals, which increases the potential risk of tetanus transmission through their scratches 1
- While no recent cases of tetanus from cat scratches have been specifically reported, the risk cannot be dismissed due to the nature of the wound 1
Tetanus Prophylaxis Guidelines Based on Immunization Status
For Persons with Complete Primary Vaccination Series (≥3 doses):
- If last tetanus toxoid-containing vaccine was <5 years ago: No tetanus toxoid-containing vaccine or TIG needed 1
- If last tetanus toxoid-containing vaccine was ≥5 years ago: Administer tetanus toxoid-containing vaccine without TIG 1
- For persons aged ≥11 years: Tdap is preferred if the person has not previously received Tdap or has unknown Tdap history 1
- For persons with documented previous Tdap: Either Td or Tdap may be used 1
For Persons with Unknown or Incomplete Vaccination History (<3 doses):
- Administer tetanus toxoid-containing vaccine AND tetanus immune globulin (TIG) 1
- Persons with unknown or uncertain previous tetanus vaccination histories should be considered to have had no previous tetanus toxoid-containing vaccine 1
- For persons aged ≥7 years who are not fully immunized against tetanus, Tdap should be given as the first dose in the catch-up series 1
Special Considerations
- For pregnant women requiring tetanus prophylaxis, Tdap should be used regardless of prior Tdap history 1
- Persons with HIV infection or severe immunodeficiency who have contaminated wounds should receive TIG regardless of their tetanus immunization history 1
- Persons with a history of an Arthus reaction following a previous tetanus toxoid-containing vaccine should not receive a tetanus toxoid-containing vaccine until >10 years after the most recent dose, regardless of wound condition 1
Clinical Pearls and Pitfalls
- Do not assume cat scratches are "clean wounds" - they should be treated as contaminated wounds requiring appropriate tetanus prophylaxis 1
- When both TIG and tetanus toxoid-containing vaccine are indicated, administer using separate syringes at different anatomical sites 1
- There is a documented case report of tetanus developing after cat scratches and bites in a previously immunized patient, highlighting the importance of appropriate tetanus prophylaxis even in vaccinated individuals 2
- Unnecessary tetanus vaccinations are common in emergency departments - ensure proper documentation of vaccination history when possible 3
- In addition to tetanus prophylaxis, consider antibiotic therapy for cat scratches if there are signs of infection, as cat scratches can lead to cat-scratch disease caused by Bartonella henselae 4, 5
Remember to thoroughly clean and disinfect all cat scratch wounds in addition to providing appropriate tetanus prophylaxis 5.