Riverina Equine Vet



Tetanus Vaccination for Horses

Tetanus is a highly fatal bacterial disease in horses. The organism Clostridium tetani, which causes the disease, lives in soil and manure. It enters the body through wounds. The bacteria multiply only in sites where there is a poor oxygen supply, such as in deep wounds. The time from when the bacteria first begin producing toxins to the first signs of tetanus may be 1–3 weeks, typically 9–10 days. The bacteria produce a powerful nerve toxin, which causes a progressive contraction (cramp) of many muscles of the body. Death usually follows within a few days of the signs first appearing. 

Tetanus is readily prevented by vaccination. The Equivac 2-in-1 vaccine provides longer term immunity against tetanus (and strangles), and Equivac TAT is available for short term immediate protection (up to 2 weeks), however is it significantly more expensive.


Suggested vaccination protocol:



Adult horses

Pregnant mares

1st vaccination

12 weeks of age

Any age



2nd vaccination

14 weeks of age

(2 weeks later)

2 weeks later


3rd vaccination

16 weeks of age

(2 weeks later)

2 weeks later



16 months of age

(12 months later), then annually

12 months later, then annually

2-4 weeks prior to foaling









Traumatic injury

Any horse with a contaminated wound should ideally receive a tetanus anti-toxin (TAT) injection to provide added protection against tetanus, irrespective of vaccination history.


Newborn foals

At birth, foals should receive a tetanus anti-toxin (TAT) injection. The primary vaccination course should then be administered from 3 months of age.


Colt castration

Colts should ideally have received a primary vaccination course as a foal, however often this is not the case. As such, colts should receive a tetanus anti-toxin (TAT) injection at the time of castration and we recommend initiating a primary vaccination course for long term protection. To avoid the cost of the tetanus anti-toxin (TAT) injection, we recommend colts be fully vaccinated PRIOR to castration.