Tetanus in Horses: Lockjaw Prevention
Tetanus is almost always fatal in horses. Vaccination is cheap insurance against this devastating disease.
Tetanus is caused by the bacterium Clostridium tetani, which produces a potent neurotoxin. The toxin attacks the nervous system, causing rigid paralysis. Horses are the most susceptible domestic animal, and the disease is nearly always fatal without intensive treatment. Prevention through vaccination is simple, inexpensive, and highly effective.
Key Points
- Horses are the most susceptible domestic animal to tetanus
- The bacterium enters through wounds, especially deep punctures or necrotic tissue
- Signs include stiffness, muscle spasms, 'sawhorse' stance, and third eyelid prolapse
- Treatment requires antitoxin, antibiotics, muscle relaxants, and intensive nursing
- Even with treatment, mortality rates exceed 75%
- Vaccination with toxoid is highly effective; boosters are needed annually or after wounds
How Tetanus Develops
Clostridium tetani is an anaerobic bacterium found in soil and feces. It enters through wounds — especially deep punctures, lacerations, or areas with dead tissue where oxygen is low. The bacterium isn't invasive; it stays at the wound site and produces tetanospasmin, one of the most potent toxins known. The toxin travels up nerves to the spinal cord and brain, blocking inhibitory neurotransmitters. This causes uncontrolled muscle contraction and spastic paralysis.
Prevention Through Vaccination
Vaccination with tetanus toxoid is highly effective. Primary series: two doses 4-6 weeks apart. Annual boosters maintain immunity. Give a booster at the time of any wound if vaccination status is uncertain. Foals receive primary series starting at 3-4 months. Pregnant mares are vaccinated 4-6 weeks before foaling to pass immunity to the foal via colostrum. Tetanus toxoid is one of the safest and most effective vaccines available.
When to See a Vet Immediately
- Your horse shows stiffness, muscle spasms, or a sawhorse stance
- The third eyelid is prolapsed across the eye
- The jaw is locked and the horse cannot eat or drink
- There's a recent wound, especially a deep puncture
- The horse is unvaccinated or vaccination status is unknown
How RVC Can Help
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.