ABSTRACT
Tetanus is a disease characterized by prolonged muscle contraction (either focal or generalized). It is caused by production of the neurotoxin tetanospasmin, usually within an anaerobic wound. There are marked differences in species susceptibility, with the horse being highly susceptible, while the dog is much less susceptible (around 600 times less susceptible) and the cat even less so. Tetanospasmin (tetanus toxin) is produced by the gram-positive, obligate anaerobic bacterium Clostridium tetani. The toxin binds irreversibly to presynaptic sites of inhibitory neurons and recovery from the clinical signs of tetanus requires the formation of new axonal terminals. The toxin is usually degraded within the gastrointestinal tract if ingested orally.
