dropsy is a symptom of a disease and not a disease in itself. The last stage is when they start to pinecone,where the scales stand out, and if they reach this stage then theres really not much else you can do.
dropsy comes from a bacterial infection and if you can seperate the fish then this would be best.
raise the temperature to 80f and this will help the fish's immune system to work better.
keep the water in really good condition with thorough gravel vacs as well.
add 1/8th teaspoon of epsom salt per 5 gallons u.s or 3 gallons u.k. feed the fish with medicated food if your u.s but in the u.k there really isnt any medicated food, so feed the best food you can, usually gelled foods.
with a bit of luck this may work, but most dropsied fish dont make it i'm afraid.
on my own fish, i used internal meds for dropsy alongside the salt and though the dropsy went, she went blind and had to be euthenised.
good luck and keep us posted.
