Within a case-control-study influencing factors and typical symptoms were identified in order to detect and reduce the risk of this livestock disease. For these purposes a questionnaire was developed, which included three points of interests, livestock management, feed assessment and animal health with livestock diagnostics. For the detection of C. botulinum specific PCR methods were developed and optimized. Furthermore a mouse bioassay for the detection of BoNTs and an ELISA for the investigation of antibody titer against BoNT/A, B, C and D were used. It was shown that the high performance dairy cows had a critical metabolism status in case as well as in control farms. The grass silage of low-grade quality as the suspected main cause didn’t have an extraordinary effect to the disease in the case farms. Instead of it floods of the green land, the fertilisation with liquid manure of sick animals and the feeding with own crop were evaluated as risk factors, which could lead to enhancement of the sickness by a circle of re-infection. Beside different neuro-motorical dysfunctions also clinical symptoms as a bad up to very bad habitus, ataxia, an untypical leg position, low ruminal contraction, laminitis, atrophy of the gluteal musculature were determined as characteristic for the disease pattern of visceral botulism. Due to successful detection of C. botulinum and its toxins in animal faeces those could be examined as the cause of the multifarious deficiencies and were the crucial factors for the disease pattern of visceral botulism.