This is how i understand dropsy: (there is a lot of good literature on the net) Dropsy is a symptom, not a disease in itself. It indicates internal bacteria, and causes the fish to swell as it cannot expell the excess fluid building up inside them. Often the swelling causes internal injuries and therefore the fish cannot recover (hence the rarity that dropsy is curable). I had one fish that got dropsy, I treated it in a separate tank with an airsotne and melafix and tonic salt (although its recommended against using this type of salt because of the contents are of that which the fish already cannot expell)- Epsom salts are recommened.A nd he fot better and is fine now! Furan 2 has been suggested if it's mild dropsy. Dropsy can be curable but it is rare. Make sure if you have a fish with dropsy to isolate it, as if the fish dies in the tank with other fish the internal fluids will ooze and be contagious to other fish. if teh dropsy is quite bad, then it's best to euthanise the fish as it suffers and may even internally explode. DROPSY IS CAUSED BY: Poor water conditions and /or stress. Poor water conditions is the main culprit. Are you doing water changes and siphoning the gravel? You need to have had your tank cycled too - you can find info on here to do this. Good luck!! I hope this has helped