Dropsy is more a symptom then a real disease.A symptom of bacterial infection [internal].Usually kidney failure I believe which results in screwed up osmoregulation and the fish swelling from the organ failure.
Usually by the time you see the swelling and protruding scales it is too late.
Now having two fish with the same issue is trouble IMO.
Many lose one fish to 'dropsy' and never realize weeks down the road that the next death is really related.
Two so close merits a much closer look at the other fish and tank parameters.
I would not leave the fish in tank with others as when the fish dies and others pick on it is how the disease is most commonly spread.