Last Updated on March 15, 2022 by Allison Price

It is caused by Clostridium Tetanii , a bacterium that is an anaerobic (doesn’t require oxygen). It can survive in soil and droplets for long periods of times.

It can enter the body through wounds. The most dangerous are puncture wounds and foot penetration wounds. However, gastric ulcers can also cause tetanus in people who eat droppings or soil that is highly contaminated.

In contaminated wounds, the tetanus bacteriaium can multiply quickly. The toxin responsible for the symptoms is the bacterium that is produced.

Clinical signs

The nerve system is affected by the toxin, which attacks the nerves controlling the muscles. If your horse is affected by the poison, you will see these symptoms:

  • Third eyelid protruding (membrane in the inner corner).
  • Extension and stiffness in the limb.
  • Spasm of jaw muscles (lock Jaw) resulting in a common expression known as sardonic smile.


Although tetanus can sometimes be treated, most horses die from it due to the inability to diagnose the problem early. Horses that are diagnosed early can receive large doses intravenously of tetanus-antitoxin via a lumbosacral perfusion.


Tetanus can be prevented by keeping your horses covered with tetanustoxoid. A primary course of vaccination includes two injections, four to six weeks apart.

The horse must be vaccinated every two years after the completion of the primary course.

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!