
Originally Posted by
Jacques
With breathing difficulties, give immediate aeration.
I would isolate this fish in a hospital tank, in case this is contagious.
Just looking in my "Manual of Fish Health", it may be fish pox (viral), nodular disease (microsporidian and myxosporidian parasites), a tumour, or lymphocystis (viral). For all of these conditions, the text says there are no reliable treatments, although fish pox is rarely fatal. It also says that surgical removal of tumours or lymphocystis growths, by a vet, may be successful.