在池塘养鱼中,草鱼增肉倍数高,生长速度快,增产潜力大。但是草鱼抗病力弱,易患肠炎、烂鳃和赤皮病(简称“三病”).“三病”在我国许多养殖地区都有不同程度的流行,一般认为是不治之症。“三病”的症状表现为:腹部膨大,肠壁里红色,肛门外突红肿,轻压腹部有淡黄色粘液从肛门流出;鳃丝腐烂发白,残缺不全,有污泥,尖端软骨外露;体表腹部两侧大部分充血、发炎,鳞片脱落,鳍条末梢腐烂。这些均可确诊为典型的“三病”.草鱼“三病”是由病毒和细菌引起的, Fish in ponds, grass carp multiples high, fast growth, yield potential. However, grass carp disease resistance is weak, susceptible to enteritis, rotten gills and red-skin disease (referred to as “three diseases.)” Three diseases “in many aquaculture areas in our country have varying degrees of prevalence, is generally considered incurable. Symptoms of ”three diseases“ are as follows: the abdomen expands, the red in the intestine wall, the swelling in the outside of the anus, the pale yellow mucus in the abdomen gently flows out from the anus; the gill filament turns white and incomplete, there is sludge and the tip cartilage is exposed; Most of the surface of the abdomen on both sides of congestion, inflammation, scales off, fin distal decay. These can be diagnosed as a typical ”three disease.“ Grass carp ”three diseases" is caused by viruses and bacteria,