tiger barb

Question
Hi,  I have a well established 30 gal tank with 1 pleco, 2 angel fish, and three tiger barbs.  I've had my barbs for over 8 months with no problems but today I noticed one of them was really bloated with it's scales sticking out and its eyes were popped out and it was breathing really fast.  I immediately seperated this fish into my hospital tank and it ended up dying within just a few minutes of being in the hospital tank.  My hospital tank is a 5 gal tank and I just took 5 gal from my main tank so I wouldn't have to worry about the water content.  I keep up on my main tank daily ensuring adequate ph and etc.  So I can't figure out what the barb died from.  I read that these signs may also be due to pregnancy of the fish, and I am just worried that I may have shocked her when I moved her....I know it sounds silly but I really love my tank and my fish.  Niether of my other barbs or other fish are showing any of the same signs and I did a 25% water change on my main tank immediately after.  What do you think this was?  Is there any way to distinguish between a pregnant fish and a sick-bloated fish?

Answer
Hi David,
Sorry for your loss. The symptoms you were describing defiantly sounds like Dropsy. It is uncertain what causes this disease and precise treatment can be difficult. The best thing to do is remove the affected fish into a separate tank and give them the best possible food, great water quality conditions, etc. If their condition does not improve, treat with a broad-spectrum antibiotic. Dropsy is difficult to treat, so unfortunately there are no guarantees. When fish are pregnant, they seem to just get "fatter". There scales do not stick out like a pinecone or display popping eyes. In your case, I believe your fish died from Dropsy.