診(zhen)斷銀(yin)(yin)(yin)魚病應采取由表及里的方法，即先檢(jian)查銀(yin)(yin)(yin)魚體外部，再檢(jian)查銀(yin)(yin)(yin)魚體內(nei)部；每一部位的檢(jian)查，都是先用(yong)肉眼檢(jian)查（簡(jian)稱目檢(jian)），然后用(yong)顯微鏡檢(jian)查（簡(jian)稱鏡檢(jian)）。著重檢(jian)查病銀(yin)(yin)(yin)魚的體表、鰓、腸(chang)道，這就是“三(san)查”。  

查體(ti)(ti)表　據一(yi)般(ban)經驗，病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚體(ti)(ti)表充(chong)血(xue)(xue)(xue)、發(fa)炎(yan)、鱗片(pian)脫落是(shi)(shi)赤皮(pi)病(bing)(bing)(bing)(bing)(bing)；若病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚鰓(sai)蓋(gai)或鰭基部(bu)(bu)充(chong)血(xue)(xue)(xue)，表皮(pi)充(chong)血(xue)(xue)(xue)不明顯，肌(ji)肉呈(cheng)點(dian)(dian)狀(zhuang)(zhuang)(zhuang)充(chong)血(xue)(xue)(xue)或塊(kuai)狀(zhuang)(zhuang)(zhuang)淤血(xue)(xue)(xue)是(shi)(shi)出(chu)血(xue)(xue)(xue)病(bing)(bing)(bing)(bing)(bing)；病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚腹(fu)部(bu)(bu)膨大，肛門(men)紅(hong)(hong)腫呈(cheng)紫紅(hong)(hong)色(se)(se)(se)，輕壓腹(fu)部(bu)(bu)有(you)(you)乳黃色(se)(se)(se)液體(ti)(ti)流出(chu)是(shi)(shi)腸(chang)炎(yan)病(bing)(bing)(bing)(bing)(bing)；尾柄及(ji)腹(fu)部(bu)(bu)兩(liang)側有(you)(you)火烙(luo)樣(yang)的(de)(de)紅(hong)(hong)斑或表皮(pi)腐爛是(shi)(shi)打印病(bing)(bing)(bing)(bing)(bing)；生(sheng)有(you)(you)棉絮狀(zhuang)(zhuang)(zhuang)的(de)(de)白(bai)(bai)色(se)(se)(se)物(wu)是(shi)(shi)水(shui)霉(mei)病(bing)(bing)(bing)(bing)(bing)；體(ti)(ti)表黏(nian)液較多(duo)并有(you)(you)小米(mi)粒大小、形似臭蟲(chong)(chong)(chong)的(de)(de)蟲(chong)(chong)(chong)體(ti)(ti)是(shi)(shi)銀(yin)(yin)(yin)(yin)魚虱病(bing)(bing)(bing)(bing)(bing)；體(ti)(ti)表有(you)(you)白(bai)(bai)色(se)(se)(se)亮點(dian)(dian)，離水(shui)2小時亮點(dian)(dian)消失是(shi)(shi)小瓜蟲(chong)(chong)(chong)病(bing)(bing)(bing)(bing)(bing)；體(ti)(ti)表有(you)(you)白(bai)(bai)色(se)(se)(se)斑點(dian)(dian)，白(bai)(bai)點(dian)(dian)之間有(you)(you)出(chu)血(xue)(xue)(xue)或紅(hong)(hong)色(se)(se)(se)斑點(dian)(dian)是(shi)(shi)卵甲藻病(bing)(bing)(bing)(bing)(bing)；部(bu)(bu)分鱗片(pian)處發(fa)炎(yan)紅(hong)(hong)腫，有(you)(you)紅(hong)(hong)點(dian)(dian)并伴有(you)(you)針狀(zhuang)(zhuang)(zhuang)蟲(chong)(chong)(chong)體(ti)(ti)寄生(sheng)是(shi)(shi)錨頭(tou)銀(yin)(yin)(yin)(yin)魚蚤病(bing)(bing)(bing)(bing)(bing)；銀(yin)(yin)(yin)(yin)魚成群在(zai)池(chi)(chi)水(shui)表面(mian)或池(chi)(chi)塘周邊狂游(you)，且(qie)(qie)頭(tou)部(bu)(bu)充(chong)血(xue)(xue)(xue)呈(cheng)紅(hong)(hong)色(se)(se)(se)，死亡(wang)多(duo)且(qie)(qie)迅速，一(yi)般(ban)是(shi)(shi)車(che)輪蟲(chong)(chong)(chong)病(bing)(bing)(bing)(bing)(bing)；病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚尾柄表皮(pi)發(fa)白(bai)(bai)是(shi)(shi)白(bai)(bai)皮(pi)病(bing)(bing)(bing)(bing)(bing)；病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚在(zai)水(shui)中頭(tou)部(bu)(bu)或嘴部(bu)(bu)明顯發(fa)白(bai)(bai)，離水(shui)后不明顯是(shi)(shi)白(bai)(bai)嘴病(bing)(bing)(bing)(bing)(bing)；銀(yin)(yin)(yin)(yin)魚下唇突出(chu)呈(cheng)簸箕(ji)口狀(zhuang)(zhuang)(zhuang)，則是(shi)(shi)因時常(chang)缺氧浮頭(tou)引起；病(bing)(bing)(bing)(bing)(bing)銀(yin)(yin)(yin)(yin)魚眼球(qiu)突出(chu)、脫落，且(qie)(qie)鱗片(pian)松(song)立，一(yi)般(ban)為池(chi)(chi)水(shui)有(you)(you)毒所(suo)致；銀(yin)(yin)(yin)(yin)魚體(ti)(ti)呈(cheng)彎曲(qu)狀(zhuang)(zhuang)(zhuang)是(shi)(shi)池(chi)(chi)水(shui)中重金(jin)屬(shu)離子含量較高或有(you)(you)機磷(lin)中毒所(suo)致。  

查(cha)鰓(sai)(sai)(sai)(sai) 打(da)開(kai)銀(yin)魚鰓(sai)(sai)(sai)(sai)蓋，檢查(cha)鰓(sai)(sai)(sai)(sai)有(you)無(wu)異樣，正(zheng)常(chang)的鰓(sai)(sai)(sai)(sai)絲(si)整齊、緊密(mi)，呈(cheng)(cheng)鮮紅(hong)色。鰓(sai)(sai)(sai)(sai)絲(si)腐爛發白(bai)，尖端軟骨外露，并有(you)污泥和黏液是(shi)爛鰓(sai)(sai)(sai)(sai)病；鰓(sai)(sai)(sai)(sai)絲(si)發白(bai)呈(cheng)(cheng)貧血狀，很可能是(shi)鰓(sai)(sai)(sai)(sai)霉病或球(qiu)蟲(chong)病；鰓(sai)(sai)(sai)(sai)絲(si)末端掛著像蠅(ying)蛆一樣的白(bai)色小蟲(chong)是(shi)中(zhong)華銀(yin)魚蚤病；鰓(sai)(sai)(sai)(sai)部(bu)浮(fu)腫，鰓(sai)(sai)(sai)(sai)蓋張開(kai)不(bu)能閉合，鰓(sai)(sai)(sai)(sai)絲(si)呈(cheng)(cheng)暗(an)淡色是(shi)指環蟲(chong)病；鰓(sai)(sai)(sai)(sai)絲(si)呈(cheng)(cheng)紫紅(hong)色并伴有(you)大量黏液多為(wei)有(you)機氯(lv)中(zhong)毒(du)所致(zhi)；鰓(sai)(sai)(sai)(sai)絲(si)呈(cheng)(cheng)紫紅(hong)色，黏液較少則(ze)為(wei)經常(chang)缺氧浮(fu)頭所致(zhi)。  

查腸(chang)道 打開病銀(yin)(yin)魚(yu)腹部(bu)(bu)，正常的銀(yin)(yin)魚(yu)腸(chang)管中充滿了食(shi)物或糞便，腸(chang)壁(bi)呈鮮紅(hong)色。腸(chang)管全部(bu)(bu)或部(bu)(bu)分充血呈紅(hong)色，腸(chang)壁(bi)不發炎(yan)(yan)是出血病；充血發炎(yan)(yan)且伴有(you)大(da)量乳黃色黏液是腸(chang)炎(yan)(yan)病；腸(chang)道呈白(bai)色且前段腫大(da)，腸(chang)內壁(bi)有(you)許(xu)多白(bai)色絮狀(zhuang)小(xiao)結節為球蟲病或黏孢子蟲病。  

根據“三查”所掌(zhang)握的(de)有(you)關情況，再結合發病(bing)季節進行綜合分析，就可以比較準確地診(zhen)斷(duan)銀魚病(bing)，從而做到(dao)對癥下(xia)藥(yao)，收到(dao)藥(yao)到(dao)病(bing)除的(de)效果。