Tetanus is a bacterial disease caused by Clostridium tetani. The bacteria produce spores that can survive for many years, living in faeces, soil and the environment. When they enter the horse’s body, generally via a wound, they wake up and become harmful bacteria.
The bacteria proliferate in tissue and this produces the toxin tetanospasmin, which attacks the nervous system. In a nutshell, it’s the spores, bacteria and then the neurotoxin which attack the nervous system in the body and cause the outward symptoms that we can see. I’ve never seen a case of tetanus in an adult horse, but I have experienced it in foals, who are more susceptible (see Facts panel, right).
Foals are particularly prone to tetanus