Tetanus Prophylaxis for Infant Dog Bite: Dosing Recommendation
No, do not administer 1500 units of tetanus immunoglobulin (TIG) to an infant—the correct dose is 250 units intramuscularly regardless of age, as recommended by the CDC. 1
Correct Dosing for All Pediatric Patients
- The standard prophylactic TIG dose is 250 units IM for both adult and pediatric patients, including infants, when passive immunization is indicated for tetanus-prone wounds 1
- The 1500-unit dose you mentioned is incorrect and represents a six-fold overdose that could cause unnecessary adverse effects and waste of limited TIG supplies 1
When TIG is Indicated for an Infant Dog Bite
Dog bites are classified as tetanus-prone/contaminated wounds because they may be contaminated with dirt, saliva, and other debris 2, 3
Vaccination History Assessment Algorithm:
- If the infant has received <3 doses of DTaP OR vaccination history is unknown: Administer BOTH DTaP vaccine AND TIG (250 units IM) 1, 2
- If the infant has received ≥3 doses of DTaP and last dose was <5 years ago: No TIG or additional vaccine needed 2
- If the infant has received ≥3 doses of DTaP and last dose was ≥5 years ago: Administer DTaP vaccine WITHOUT TIG 2
Critical Administration Details
- When both DTaP and TIG are given concurrently, use separate syringes at different anatomical sites to prevent interference with active immunization 1
- For infants, appropriate injection sites must be selected based on muscle mass availability 1
Special Immunocompromised Considerations
- Infants with HIV infection or severe immunodeficiency should receive TIG (250 units) regardless of their tetanus immunization history when they have contaminated wounds like dog bites 1, 2, 4
Primary Series Completion
- Infants requiring TIG must complete the full 3-dose primary DTaP series: doses at 2,4, and 6 months of age, with subsequent boosters at 15-18 months and 4-6 years 1, 5
- The accelerated schedule can begin as early as 6 weeks of age if indicated, with doses separated by at least 4 weeks 1
Additional Wound Management
- Thorough wound cleaning and debridement are essential first steps in tetanus prevention, as proper wound care removes debris that might harbor Clostridium tetani spores 5, 6
- Prophylactic antibiotics (amoxicillin-clavulanate) are indicated for dog bite wounds, particularly puncture wounds, to prevent infection with Pasteurella multocida and other pathogens 3, 6
Common Pitfall to Avoid
Never confuse adult dosing with pediatric dosing for TIG—the 250-unit dose is standardized across all ages and should never be weight-based or arbitrarily increased 1