Tetanus, or lockjaw, is a non-contagious neurological disease that results from a bacterial infection. Horses are particularly vulnerable to tetanus, with individuals of all ages and breeds affected worldwide.

Tetanus spores are particularly dangerous for horses as they survive for long periods and can be found everywhere in the environment, including in soil, dust, manure and even the digestive tract. [1][2][3]

The smallest wound can make a horse susceptible to tetanus once these spores enter the body. Fortunately, tetanus is entirely preventable with regular immunization and other protective measures. [4]

Treatment of tetanus involves the administration of antibiotics, antitoxins, tranquillizers or other medications to minimize clinical signs and make the horse more comfortable. [3]

The prognosis for affected horses is generally very poor, often resulting in death or euthanasia. However, the outcome depends on individual factors, including vaccination status and the supportive care provided. [5]

Tetanus in Horses

Tetanus is a bacterial disease that is frequently fatal in horses and humans without quick medical intervention. Horses are more sensitive to tetanus infection than most other animals including cattle, dogs and humans. [2]

The infection is caused by the spores of the Clostridium tetani bacterium, which can be found throughout the environment. All soils worldwide are presumed to be contaminated with C. tetani to some degree. [5]

These spores enter the horse’s body through deep wounds, although horses with superficial wounds are also at risk of infection. Horses with ulcers or wounds in the gastrointestinal tract can be infected after ingesting infected feces. [3]

Under anaerobic (low oxygen) conditions, as found in wounds, these spores create a potent neurotoxin called tetanospasmin (TeNT) and a hemolysin called tetanolysin.

TeNT causes uncontrollable muscle contractions and spasming in the body by blocking neurotransmission. Tetanolysin causes tissue necrosis (death), which ensures anaerobic conditions and proper breeding grounds for bacteria. [1][5]

Gastrointestinal Tract

C. tetani spores can be found in the horse’s gastrointestinal tract, where they can survive undetected for long periods of time without causing infection or clinical signs in the horse. These spores can spread between animals through feces. [3]

If a horse with gastric or intestinal ulcers ingests C. tetani from another horse’s feces, bacteria can enter circulation in the body through these wounds. It has been suggested that 10-20% of horses have C. tetani in their feces. [6]

Maintaining a healthy gastrointestinal tract and preventing ulcers may help ward off tetanus infection by limiting entry sites into the circulatory system.

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