1发病池塘现场调查这是诊断各种疾病都需要做的第一步,主要内容包括:①调查有关的环境因子,包括了解水源中有没有污染源,池塘的水质情况,周围农田、工厂有无污水废水排入等情况,池塘中是否有作为某种寄生虫的中间寄主,周围是否有作为某种鱼类寄生虫的终末寄主等;②调查饲养管理 This is the first step in the diagnosis of various diseases. The main contents include: (1) Investigating relevant environmental factors, including understanding whether there is any pollution source in the water source, the water quality of the pond, the surrounding farmland and the factory whether there is any sewage Wastewater discharge and so on, whether there is an intermediate host in the pond as a host of parasites, whether there is a terminal host around as a fish parasite, etc .; and ② investigation of feeding and management