Infection in fish pond differs, it could be viral infection, fungi infection, bacterial infection, parasites infection etc, but symptoms you should watch out for includes:
Protruding body (swollen body).
Fin rot (decay fin).
Floating upside down.
The fishes will start turning white.
Small white spots on their body.
Inactive (struggling to swim).
Loss of colour.
Red vein on the body.
The infected fish will find it difficult to breath and scratching.
They loss appetite (inability to feed properly).
Swollen head and bulging eyes.
Once you discover any of these symptoms on any fish, isolate the fish immediately from the pond to avoid mass die off of the fishes in the pond, because if left alone the infection will spread to other fishes in the pond, change water immediately, avoid contaminated water and chemicals into the pond, avoid overcrowding of the pond.
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