Tetanus is caused by the bacterium Clostridium tetani which produces toxins that affect the central nervous system. The organism, which can form spores, lives in the large intestines and faeces of many mammals, including pigs and in certain soils. It must enter through a dirty abrasion or a cut. In the sucking pig the most common source is castration. Tetanus spores are found in the soil and this disease can be a problem in outdoor pigs. The incubation period is from 1 to 10 weeks. It would be uncommon to see disease in the sucking piglet under 2 weeks of age. The affected piglet is hypersensitive, shows stiffness of legs and muscles, an erect tail and muscular spasms of the ears and face. A multivalent clostridium vaccine containing tetanus toxoid is highly efficient in preventing disease and could be used in pregnant sows if a herd has a problem. Castration techniques should also be checked because unhygienic methods can lead to infection and tetanus 2-8 weeks later.