Does a small dog bite from a vaccinated domestic dog require a tetanus (Td or Tdap) vaccine booster?

Tetanus Vaccination After Small Dog Bite from Vaccinated Dog

A small dog bite from a vaccinated domestic dog still requires tetanus prophylaxis based on YOUR vaccination history, not the dog's vaccination status—the dog's rabies vaccination is irrelevant to tetanus risk. 1, 2

Wound Classification

• Dog bites are classified as "non-clean wounds" or "contaminated wounds" that may be contaminated with dirt, saliva, or other materials, regardless of whether the dog is vaccinated. 2
• The vaccination status of the dog is irrelevant to tetanus prophylaxis decisions—tetanus comes from Clostridium tetani spores in the environment (soil, dirt, saliva), not from the dog's vaccination status. 1, 2
• This classification determines a critical 5-year interval (rather than 10-year) for booster administration. 1, 2

Vaccination Algorithm Based on Your Immunization History

If your last tetanus vaccine was <5 years ago:

• No tetanus toxoid-containing vaccine or TIG is needed. 1, 2

If your last tetanus vaccine was ≥5 years ago:

• Administer tetanus toxoid-containing vaccine (Tdap or Td) WITHOUT tetanus immune globulin (TIG). 1, 2
• Tdap is strongly preferred over Td if you have not previously received Tdap or your Tdap history is unknown, as this provides additional protection against pertussis. 1, 2
• For persons with documented previous Tdap vaccination, either Td or Tdap may be used. 3, 2

If you have <3 lifetime doses or unknown/uncertain vaccination history:

• Administer BOTH tetanus toxoid-containing vaccine AND TIG (250 units IM) immediately, using separate syringes at different anatomical sites. 1, 2
• Begin a complete 3-dose vaccination series. 1, 2

Critical Time Intervals

• For contaminated wounds (including dog bites): booster needed if ≥5 years since last dose. 1, 2
• For clean, minor wounds only: booster needed if ≥10 years since last dose. 1
• Do not confuse these intervals—this is the most common error in tetanus prophylaxis. 1

Special Populations

• Pregnant women: Use Tdap regardless of prior Tdap history if tetanus prophylaxis is indicated. 2
• Immunocompromised patients (HIV infection, severe immunodeficiency): Receive TIG regardless of tetanus immunization history. 1, 2
• History of Arthus reaction: Do not receive tetanus toxoid-containing vaccine until >10 years after the most recent dose, regardless of wound severity. 1, 2

Common Pitfalls to Avoid

• Do not assume a "small" bite from a "vaccinated" dog is a clean wound—all dog bites are contaminated wounds requiring the 5-year interval rule. 2
• The dog's vaccination status protects against rabies transmission, not tetanus—these are completely separate considerations. 2
• More frequent doses than recommended may be associated with increased incidence and severity of adverse reactions, including Arthus-type hypersensitivity reactions, but when clinically indicated for wound management, the benefits outweigh risks. 1