Goldfish with swollen belly..!

[AshBee]

For the last few months my goldfish's belly has been swelling up, it wasn't really noticable at first but now it looks like its going to explode!
I've done a little research and most people seem to think its dropsy but the scales are not sticking out, and anti-internal bacteria medication hasn't worked.
He is on his own in a tank (although there is no filter, we do the 25% water change every week) and his faeces is bright red.

Does anyone know what this could be, and how to treat it? It must be very uncomfortable for the poor fish!
Thanks

[divegirl]

Hi, firstly, a goldfish really can not be kept in a tank without a filter, they are one of the messiest fish there is!
It could be constipated, if so then feeding a small piece of pea can get the bowel moving. Take one frozen pea and drop it into a cup of boiling water, leave it for a minute or two then peel it, crush it and feed it to the fish! Starve for two days then repeat.
As for the colour of his poop. what are you feeding him?

TBH sounds like the start of dropsy and he will 'cone' eventually.

How big is the tank, water stats and how old is the fish?

Lisa x