Symptoms: Among the first signs of dropsy is the lack of equillibrium in the puffer's swimming pattern.  Since puffers lack scales, there is no "pine cone" appearance to infected fish.  Look for prolonged swelling in the body cavity.  Don't be alarmed if your puffer looks "puffed", but do be concerned if it stays like that for a prolonged period of time. (long after whatever danger that made it puff is gone) There may be lesions or ulcers present as well. This disease must be caught early if your puffer is to survive.

Treatment: Anti-biotics geared towards gram-negative bacteria. ("Maracyn-Two" and the like)  Dead fish should be removed immediately, to prevent spread of the disease by cannibalism.

Background:  The bacterium that plays a role in dropsy are called Pseudomonas punctata, a small rod-shaped croorganism with one flagellum at the end of its body. It is not affected by either terramycin or aureomycin.  These bacteria infect the internal organs of the puffer, inflaming them.  Post mordem observations include inflammation of the intestines, discoloration of the liver, and other internal organs almost "growing together".  Puffers recovering from dropsy may experience deformities in fin and bone.   Dropsy may be due to a primary virus infection, which is complicated by an adjacent and secondary infection of Pseudomonas punctata; the bacterium in question.