Tetanus is a very serious disease, frequently death for the mammals and humans. The cause is a toxin produced by the bacterium Clostridium tetani which normally lives in the soil where it can survive for many years. The organism can gain entry to the body via wounds, particularly small puncture wounds which may not be immediately noticeable. The animal loses the control of its nervous system, and it results in serious muscular contractions.
Equids are the animals which are the most sensitive to this very resistant bacillus which is everywhere in the environment - i.e. : ground, manure... Thus any wound, even tiny can be infected; it must be disinfected.

Contamination

The bacillus Clostridium tetani is of type anaérophobe, it can develops only in an environment without oxygen. This bacillus likes particularly the dead tissue where the blood circulation was stopped by a wound.
The bacillus tetanus is component normal of the intestinal flora of equids and other herbivores. When the bacilli are expelled from the body of equids (manure), the conditions of survival are degraded, and the bacillus is transformed into spore to resist its new environment and to wait better conditions of survival.
These spores are extremely resistant: they resist 15 minutes at 100°C, many disinfectants, and they can survive more than 30 years safe from the light.

When an donkey is wounded, the spores can return in contact with the wound, and the bacillus can then proliferate again. They are multiplying in the wound, it produces a toxin which is a million times more toxic than strychnin. This toxin will be fixed by a connection between the motor nerves and the muscles of the organism and thus will block the donkey of the nerve impulse by causing violent contractions.

Symptoms

In the donkey the causes of tetanus are multiple. Here, four principal sources:
- accidental tetanus after having a wound
- surgical tetanus after surgical operation
- tetanus obstetrical by the mare after foaling
- umbilical tetanus to the foal

The first symptoms generally appear after a few days (2-4 in the very vascularized zones, after a week elsewhere), but the bacillus can stay as spores in the organism for several months if the conditions for its growth are not optimal.
These symptoms start as stiffness causing the donkey to move reluctantly, head and ears are extended, there is evidence of muscular spasms affecting the muscles of mastication and making eating and drinking difficult. It becomes hypersensitive with the external stimuli (sounds, light, touch), and we can note a hypersalivation.
A common method to differentiate the disease of the other neurological diseases are to check the movement of the third eyelid in the corner of the eye when we clap our's hands: this one closes in an uncontrolled way.
The frequency and the power of the muscular spasms increase with the evolution of the disease, and a fatal outcome occurs when the spasms and the contractions reach the respiratory muscles.

Prevention - Treatment

There is no treatment to inhibit the toxin when this attacks the nerves, and the success of the treatment is function down to the sped of the prognosis. But in spite of powerful treatments, more than 50% of equids do not survive this disease.
On the other hand, vaccination against tetanic toxin ensures a quasi total protection.

The vaccination protocol recommended is the following:

On animals not vaccinated or whose last recall is up more than 3 years, if the animal has a wound or an operation, we practice the serovaccination. It will be followed by another injection 3 to 4 weeks later, then an annual recall.

The prevention of the umbilical tetanus can be done with the preventive serum injected during the first hours of the foal's life.