There are two diseases caused by bacteria that have severe effects in horses.
This disease is caused by a neurotoxin that is released by the bacteria Clostridium tetani. These bacteria are always present in the horse's environment as spores that persist for many years. These spores gain entry into the horse’s body via a wound and symptoms occur 4-21 days after the initial infection. These symptoms include stiffness and cramping of body muscles resulting in extreme stiffness and eventually death. Treatment is expensive, time consuming and generally unsuccessful. Fortunately, the vaccine is very effective if used appropriately.
This disease is caused by the bacteria Streptococcus equi. Strangles is highly infectious and is introduced into the horse’s environment via a carrier animal. The bacteria cause an upper respiratory tract infection and the formation of abscesses around the throat area.
Vaccinations are a reliable, effective and simple aid in the prevention and control of tetanus and strangles. The cost and effort of vaccination is small compared with the probable expense of treatment.
Tetanus toxoid is the vaccination against tetanus and vaccinations are usually started at about 3 months of age. The program involves 2 vaccinations performed 4-6 weeks apart followed by a booster vaccination 12 months later. To ensure lasting immunity, horses should be vaccinated every 3-5 years or at the time of injury. Vaccinating mares and giving them a booster 2-4 weeks prior to foaling will protect foals younger than 3 months old.
The strangles vaccination involves an initial course of three doses administered 2 weeks apart, followed by a booster every 12 months. All horses should be vaccinated, especially those that frequently come in contact with other horses (i.e. at stud, events, shows or at races). Foals can be vaccinated at 3 months of age and younger foals can be protected by vaccinating the mare two weeks before foaling.
The tetanus and strangles vaccinations exists as 2 separate vaccinations or as one combined dose which is equally effective.
At the time of injury tetanus toxoid is not an effective protection for unvaccinated horses. These horses should receive a tetanus anti-toxin as well as tetanus toxoid at the time of injury. The anti-toxin gives protection that will last 3 weeks and the toxoid will help to develop a long lasting immunity to disease.