Tetanus

Clostridium tetani is a bacterium that produces a deadly toxin. It can live in soil as highly resistant spores for several years. It causes disease in horses when it gains entry to a wound in eather the skin or the bowel lining and starts to multiply and produce toxin.
The toxins cause a type of paralysis in which the muscles become stiff and hard, unable to relax or contract.

Cause
Tetanus spores prefer an environment with no oxygen in it. So when they establish themselves in a deep wound such as that caused by a nail in the foot or a stab wound caused by a branch, or under a burn scab, they start to multiply and produce toxin, which travels along nerves to the spinal cord and then to the brain.

Symptoms
Holding the horse´s head up characteristically causes a muscle spam to pull the third eyelid across the eye.
The ears remain pricked because the muscles at their base become paralysed. The gait becomes slightly tilted at this stage as the main muscles of locomation are affected.
If the muscles involved in breathing become affected, then the condition becomes fatal.

Treatment
Penicillin kills the clostridium, but large dosis of antitoxin are then needed to counter the toxin already produced. Intensive nursing, usually in quiet, dark surroundings to avoid stimuli, is needed to keep the horse alive whilst recuperation takes place. Although many other species of animal are affected with tetanus, horses are particularly susceptible to it. Tetanus is a highly distressing disease for both horse and owner, and it is so much better to plan ahead and avoid the risk altogether by instigating a vaccination policy.