I've just moved the fish into a wee breading tank to keep away from the other fish, and one of the red spots has by the looks of things busted and is sticking out!!!
By the looks of things its the fishes belly, pretty ugly i know and really don't no what to do!!! Its still in the wee tank alive but douth the well part!!!
There were only three red spots on its belly before they burst!!
It REALLY sounds like dropsy to me. Try using marycin, but it may be too late.
Make sure the water is clean because one of the causes is poor water conditions.
Good luck, hope it helps.