[Listeriosis of lambs, its occurrence in a large sheep flock and experiences with a possible immunization]

There are regional differences in the aetiology of the CNS form of listeriosis; whereas in some flocks it is predominantly the adult animals which are affected, other units encounter substantial lamb losses with only small numbers of diseased ewes. Attempts at treatment are only likely to be successful with the septicaemic form of the disease. The evaluation of a vaccine to reduce lamb losses caused by listeriosis is problematic. The fact that the live vaccine which is usually tested is a highly virulent vaccine, which may under certain circumstances cause listeriosis in lambs, makes its further use indefensible in our opinion.