Infections are major factors affecting fishes in the pond, most especially the juvenile fishes, which could be a serious issue in the pond.
Most infections such as viral infections (virulent herpesvirus infection), bacterial infections (such as Pseudomonas fluorescens) which could lead to fin rot and fish dropsy, fungal infections, water mould infections, metazoan parasites, unicellular parasites, parasites such as Helminths, etc, could cause fish diseases, which usually leads to mass die off of the fishes in the pond.

How to Prevent Diseases

Full post here

https://medium.com.ng/best-method-to-prevent-diseases-from-fish/

Thanks for the info