My Adolfoi Catfish Dying

[Marisa_allen]

Help my Adolfoi is dying and there are no signs of disease apart from rapid breathing. What is the best course of action? I had 3, one died about a month ago, its belly had a red tinge to it, almost as if it were bleeding internally. This one has no signs apart from rapid breathing.

I have removed it from the tank and added a little sea salt as I heard sometimes this can help revive fish (desperate attempt here).

Is this common with Adolfoi to die mysteriously?

any help will be appreciated.

Thanks

 

[WILDER]

Red patches on the belly is septicemia and hard to cure once it has progressed, corys are very prone to bacterial infections, sounds like this cory has a bacterial infection too, once they labour breath like it doing they don't make it sorry, has the cory darkened in colour.