The main constraint to the aquaculture development is the disease, which hampers the production and economic cycle very badly. A variety of pathogenic organisms produce infectious disease in fish and the diseases occur frequently in nursery, rearing and grow-out ponds causing serious concern to aquaculturits. Initiation of disease in fish is a complex process interacting set of circle of the host, pathogen, and environment creating a conducive condition for an outbreak of disease. The impact of various abiotic and biotic factors on the prevelance/occurrence of the disease in coldwater fishes has not been studied well. Also the fish diseases prevalent in Wular lake (Asia?s largest freshwater lake) was completely unexplored till the present research was carried out. The results of the work can be practically applied in farms for prevention of the outbreak of the disease in coldwater areas.