一、症状和诊断 发病后期区别明显,较易鉴别,而发病早期两者外观症状极为相似,病鱼体色发黑,体表轻微充血或出血,病鱼离群独游,游动缓慢,食欲减退,剖开鱼肚,两者均肠壁充血,不同之处,活检时,前者肠壁弹性较好,肠腔内 First, the symptoms and diagnosis of late onset significantly different, easier to identify, and early onset of the appearance of the two symptoms are very similar, diseased fish body color black, mild congestion or bleeding on the surface, disease fish outing tour, slow swimming, appetite Decreased, cut fish maw, both of the intestinal wall congestion, the difference between the biopsy, the former better wall elasticity, intestinal lumen