This chapter documents the logics underpinning farmers' management practices of an emerging disease. In the area of our survey, Vietnamese farmers, who are one of the front lines of the fight against H5N1, are called upon to collaborate to the international fight against the virus. Our study highlights that direct (poultry mortality) and indirect impacts (consequence of the measures imposed by the government to contain the virus, fluctuation of consumers' demand, etc.) tend to be relatively limited when compared to the permanent state of instability which characterises the context of poultry production in the surveyed village. This instability is mainly related to numerous and regular poultry infectious diseases and market fluctuations. If international community considers H5N1 as a zoonotic risk and a pandemic threat which asks for emergency tools, H5N1 is framed by the farmers of our study as an epizootic problem manageable through routinised measures. These measures aim at minimising the economic impact of the disease rather than preventing poultry and Human from the disease. Consequently, local management of the disease cannot fit with the precautionary approach promoted by the international community.