Probably due to internal inflammations most of us dont catch until too late, that is by the time fish shows external symptoms.
This could also been started external infection and progressed internally but my guess would be systemic (internal) problems.
I have brought back numerous fish when caught on early stages, by observing not just their swimming behaviors/eating habits but also their social behaviors.
Need to observe fish in many categories to suspect possible complications.
Key is how fast you can catch the problem thus requires close monitoring.
If memory serves, Kana can be absorbed thru skin from water. For more info, google novalek.com and click on Aquavet for more info.
Hope this helped.
This could also been started external infection and progressed internally but my guess would be systemic (internal) problems.
I have brought back numerous fish when caught on early stages, by observing not just their swimming behaviors/eating habits but also their social behaviors.
Need to observe fish in many categories to suspect possible complications.
Key is how fast you can catch the problem thus requires close monitoring.
If memory serves, Kana can be absorbed thru skin from water. For more info, google novalek.com and click on Aquavet for more info.
Hope this helped.