severely bloated goldfish

Question
QUESTION: I have never even been aware of any disease about bloating goldfish until today. I have a 1000 gallon pond with about 12- 15 fish. I do not use any chemicals. The pond is 8 years old & this is my first fish. For a few years this fish has been bloated but has maintained the same size for 2 or 3 years until recently the bloat has more than doubled! It's shocking! Is there anything I can do to actually try and save this fish?

ANSWER: Are each of the fish's scales raised, almost resembling a pine-cone?  What is sounds like you are describing is dropsy.  This often points toward liver failure and other internal atrophy.  Unfortunately, this is not very treatable, as the bloating is a very late symptom signifying that the fish has already sustained a substantial amount of damage.  I am sorry if this is the case.  The best thing you can do is a partial water change, perhaps 200 gallons.  This will really only help if there is a high concentration of ammonia or nitrate in the water, but it is never a bad thing to do a water change.

There is also a slight possibility of the fish being a female and being pregnant.

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QUESTION: Only 1 fish has the problem. I read about putting the bloated fish in another container with Epsom salts. What exactly does this do? I have a 100 gal container (livestock water bowl) %26 for 5 years I brought the fish in for the winter %26 this was the winter home, last 3 years I left them in the pond. I do not believe that this fish is pregnant because the look is totally unnatural. Like I said I have had her for 8 years. How does this happen %26 will the other fish be affected? Thank you for your time, awaiting your reply....Mary

Answer
A salt bath, as it is often called, is meant to kill any external parasites the fish may have.  It is a good idea for the other fish (and for the infected fish if it is being picked on) to separate it from the others.  However, this water will quickly become ammonia-laden because of the lack of a strong biological filter.  Some fish are more susceptible to certain diseases than others, and dropsy is one disease that typically only affects one or very few fish at a time.