鱼类暴发性出血病是近１０年来在我国淡水养鱼区的主要流行病之一,特别是最近几年病情持续,病势凶猛,且用常规药物防治往往难以收效,有时还致病情恶化加重。据调查,其发病原因为:①养殖水环境的污染程度已普遍较以前加重;②感染该病的主要病原体如气单胞杆菌产生变异,其内毒素的毒力增强;③病原体 The outbreak of fish fulminant hemorrhagic disease is one of the major epidemics in the freshwater fish-farming area of ​​our country in recent 10 years. Especially in recent years, the condition is fierce, and the treatment with conventional drugs is often difficult to be effective and sometimes aggravating. . According to the survey, the causes of the disease are as follows: (1) The pollution degree of the aquaculture water environment has generally been aggravated compared with the previous ones; (2) the main pathogens infected with the disease, such as Aeromonas spp., Have been mutated and their endotoxin toxicity has been enhanced; (3)