Tetanus occurs when a wound becomes infected with bacterial spores of Clostridium tetani. Spores are found in the soil. Once in the wound the spores germinate, multiply and produce a very powerful poison which affects the muscles. Some cases of tetanus occur from wounds that are so small they are not noticed. Horses are the most susceptible of all domestic animals to tetanus. An affected horse moves with a stiff-legged gait, often with the tail held out stiffly and the ears pricked. As the disease progresses the muscles become so rigid and stiff that the horse may fall and not be able to get up again. Convulsions may occur and death is caused by paralysis of the breathing muscles. Treatment is difficult, time consuming, very expensive and often unsuccessful. It involves the use of tetanus antitoxin to neutralise unbound circulating toxin, penicillin to prevent further growth of C. tetani, muscle relaxants to relax the rigid muscles, and supportive therapy until the toxin is eliminated or destroyed.

Vaccination is the only way to provide safe, effective long-term protection against tetanus. If an unvaccinated horse is injured, tetanus antitoxin should be administered to provide immediate but short-term (3 weeks) protection. At the same time a vaccination program should be commenced to develop long-lasting immunity.

The tetanus vaccine may be administered intramuscularly on one side of the neck, while the tetanus antitoxin is injected subcutaneously on the other side of the neck. A separate syringe and needle should be used for each product. This will result in both immediate and long lasting protection.

Vaccination is the only way to provide long term protection against tetanus. For all horses and foals, three months of age and above, the primary vaccination course consists of two injections four weeks apart, followed up by a booster dose one year later. Boosters after this are recommended every five years.


This is a highly contagious respiratory disease caused by the bacterium Streptoccocus equi that causes fever, swollen lymph nodes, thick nasal discharge and difficulty breathing and eating. Most cases heal with no complications but some animals become carriers and others can suffer joint, lung or heart damage and in some cases death. The bacterium can spread between horses sharing floats, yards and tack so competition horses are at greatest risk of catching the disease. Strangles can be prevented with vaccination, initially three vaccinations given 2 weeks apart, followed up with an annual booster. Tetanus vaccine can be given at the same time. As with most diseases prevention is the best was of managing strangles.