Aspects of animal welfare and food safety in case of feed incrimination with selenium in a fattening pig farm

Objective: In this study, we highlight the aspects of animal welfare and food safety that have to be considered, if fattening pigs have been exposed to mixed feed containing an extensive overdose of selenium. Material and methods: After assessing a thorough anamnesis, clinical symptoms mainly neurological disorders and spontaneous deaths were recorded among affected pigs. In order to rule out notifiable diseases and to confirm the presumptive diagnosis "selenium toxicosis", the examination was extended to further samples. Animals were then selected for pathomorphological and histological examination, and blood, tissue and feed samples were submitted to laboratory testing to determine the selenium concentration. Results: Overall, 751 growing and finishing pigs were exposed to the feed containing an accidental overdose of selenium. Assuming the selenium was brought into the mixed feed only by the mineral supplement, it was calculated that this was loaded with 2.5 g/kg dry matter. Nearly all pigs either showed clinical symptoms or died spontaneously within 72 hours following exposure. Taking this and further aspects of animal welfare and food safety into account, decision was made to cull all pigs that were still alive. Conclusion: This case report highlights the welfare issues and aspects of food safety that should be considered by the attending veterinarian, when severe outbreaks of diseases like toxicosis are not managed by authorities.