Tetanus (lockjaw) is a highly fatal disease, caused by a potent neurotoxin elaborated by the anaerobic, spore-forming bacterium Clostridium tetani. These organisms are present in the intestinal tract and feces of horses, other animals, and humans and are ubiquitous in soil, especially soils that are heavily contaminated by fecal matter.
Transmission: The most frequent sites of infection in horses are soft tissue-injuries (including surgery) and puncture wounds to the foot.
Incubation Period: The incubation period is typically 1 to 3 weeks but can take up to several months.
The severity of the symptoms and rate of the progression of the disease depends on the age and size of the horse and the dose of toxin. Tetanus is expensive to treat and has a high mortality rate; therefore all horses should be actively immunized using tetanus toxoid as part of the core vaccination program.