一是观察体表．病鱼身体两侧肌肉、鳍基部充血，有时眼睛也充血，剥开皮肤时，肌肉呈不同程度的点状充血，病情严重的，全身肌肉呈深红色，则为出血病，病鱼体表局部发炎、充血、鳞片脱落，鳍条末端腐烂，鳍条裂开，则为赤皮病；肛门红肿、发炎充血的为肠炎病；病鱼尾柄及腹部 First, observe the body surface. Sick fish on both sides of the body muscles, the base of the fin congestion, sometimes the eyes are also hyperemia, peel the skin, the muscle showed varying degrees of punctate congestion, a serious condition, the whole body was dark red muscle, then hemorrhagic disease fish body surface local Inflammation, congestion, scaling off, the end of the fin decay, ray split, then the red-skin disease; anal swelling, inflamed red intestine inflammation;