To work properly, the ManePoints website requires that you use a javascript-enabled browser. Please turn on your javascript, or upgrade to javascript-enhanced browser. More information . D.V.M. The disease usually occurs following a deep, penetrating wound such as a hoof puncture from a nail or sharp object. It may also occur following castration or umbilical infections in foals where necrotic tissue is present.
Horses top the list of mammals most susceptible to the causative bacterium.
Tetanus is caused by Clostridium tetani, a bacterium whose spores are capable of surviving in the soil for many years. Additionally, the organism is considered a normal inhabitant of the horse's gastrointestinal tract. As a result, horses are frequently exposed to the organism in the barnyard or pasture. When anaerobic conditions are met, the bacterium releases a potent toxin that is transported in the blood to the central nervous system where it wreaks havoc and ultimately causes paralysis and death. The incubation period for tetanus is anywhere from several days to a month or more, depending on the wound environment and the proximity of the wound to the central nervous system.