Its not contagious, but its generally poor water quality that causes it so I'd recommend changing about 60-70 percent of the water so your other fishes wouldn't catch dropsy for the same reason.
From what they called 'Dropsy' what we know of today as Edema. A painful accumulation of fluid that causes severe swelling.
To my knowedge there is no proven cure for dropsy. Some pet shops carry medications that 'claim' to cure almost every disease and problem including dropsy but I have never heard of them working successfully on dropsy. I would euthanase the fish.
Dropsy is the former name for oedema
In a fish, dropsy is fluid buildup. This fluid retention can be a symptom of a serious problem, such as a type of infection.
Most types of fish can get dropsy, although in my experience, it is more common in live bearers and tetras.
Dropsy
Dropsy
swelling or edema
Jean Baptiste Emile Dropsy was an Art Nuveau jewely engraver....died in 1928. His work was exquiste!
Dropsy isn't a disease in itself. It is a symptom of another problem. The only thing you can do for dropsy is treat with a strong medication. I would use Maracyn I and Maracyn II in combination and keep the water very clean. That is your best bet.
Paul Dropsy has written: 'Mon village dans la tourmente' -- subject(s): World War, 1939-1945, History