Tetanus is a nervous system disease that a horse usually contracts through an infected puncture wound. The most common symptom is stiffness and lockjaw, as well as fever. Tetanus is diagnosed through a physical examination and sometimes a blood test to identify the presence of the Clostridium tetani toxin. Treatment usually involves antibiotics and antitoxins, but the prognosis is generally poor. Tetanus is best prevented through regular vaccination and maintaining a clean and safe stall for your horse.
What Is Tetanus?
Tetanus is a potentially fatal nervous system disease caused by the bacteria toxin Clostridium tetani. Tetanus is commonly known as lockjaw and leads to muscle spasms, particularly in the jaw and neck. The toxin multiplies rapidly and does not need oxygen to live. The toxin can survive for a long time and usually enters the body through a puncture wound, but can also be ingested. Horses are particularly susceptible to tetanus and will often procure wounds on the sole of the foot.
Symptoms of Tetanus in Horses
It may take ten days to two weeks for symptoms of tetanus to appear. Once you notice symptoms, visit your veterinarian immediately.
The most common symptom of a tetanus infection is stiffness in the head and neck, but the hindquarters and wound site may be affected first. The stiffness will spread to the jaw, making it difficult or impossible for a horse to open its mouth. The nostrils may be flared as well. As tetanus progresses, violent spasms will become more intense and easily triggered and your horse will become increasingly agitated. As the days go on, the horse will become stiffer, taking on a ‘“sawhorse” stance with its head and tail arched downward. Fever will then develop, accompanied by sweating, increased pulse, heightened respiration rate, and congestion.
Causes of Tetanus
Horses can contract tetanus in two ways.
- Puncture wounds: Tetanus-causing bacteria lives in soil, dust, and manure and typically enter the body through an open wound. This often happens through wounds in the foot, when a horse steps on a sharp object, and then on soil containing the bacteria. Once the bacteria enter the wound, it multiplies and blocks nerve messages, causing the muscles to tense up.
- Ingested bacteria: In addition to puncture wounds, horses can contract tetanus by ingesting bacteria. If a horse eats contaminated soil, dust, or manure, it can enter the body and cause infection. Eating manure is uncommon in horses, so this usually occurs when a horse eats contaminated feed.
Diagnosing Tetanus in Horses
A vet will diagnose tetanus in a horse by examining physical symptoms, medical history, and sometimes with a blood test to confirm the presence of the tetanus-causing toxin. A vet can usually make a diagnosis if your horse is exhibiting distinctive signs of tetanus, such as a locked jaw, in conjunction with a puncture wound.
Treatment of tetanus in horses begins with thoroughly cleaning the wound and surrounding area. Your vet will prescribe large amounts of antibiotics and antitoxins to stop the bacteria from multiplying further. If a horse has already been vaccinated against tetanus, your vet may administer an additional dose.
After the tetanus infection has been treated, your vet will advise palliative care methods. For horses still able to eat, You should place food and water at a height that is easy for the horse to reach, and you should keep your horse in a secluded, dark stall to avoid over-stimulation in its already agitated state. If the horse cannot stand, it may be put in a sling to keep it on its feet. Your vet may also prescribe muscle relaxants, sedatives, and IV fluids.
Prognosis for Horses With Tetanus
The prognosis for horses with tetanus is poor, and most will die or be euthanized. When detected early, treatment can be effective, but in many cases, by the time the horse receives a diagnosis, it's too late. The prognosis is more optimistic for horses who can still stand, and they will improve within two to six weeks, but 80% of horses will die.
How to Prevent Tetanus
Tetanus is easily prevented in horses. Your horse should be vaccinated against tetanus every two years, but most horse-owners vaccinate yearly. Foals need to be vaccinated after about four months, and if the mare is vaccinated, the foal will receive some protection from the colostrum. In addition to vaccinations, you should make sure your horse's living space is clean and keep sharp objects off of the ground.
Is tetanus fatal?
Tetanus in horses is often fatal due to late detection. If you notice any symptoms of stiffness in your horse, visit the vet right away.
Is there a vaccine for tetanus in horses?
There is a very effective vaccine for tetanus in horses that is included in its general inoculations as a foal. The vaccine should be re-administered every other year.
My horse is stiff but doesn't have a puncture wound. Could it still be tetanus?
Your horse can contract tetanus through ingesting the bacteria in contaminated soil, manure, or dust. A puncture wound is not necessary to the development of the infection.
Tetanus. UC Davis Center for Equine Health.