Goldfish side swollen

[Kaykay101]

One of my goldfish that I've had since at least June of 2018 (and was in a pond before that) has developed a swollen side in the last month or so. I'm feeding Cobalt Goldfish Color sinking pellets and besides one of the other goldfish having some tumors my others show no signs of anything. It's a 75 gallon tank with a Seachem tidal 110 and Fluval fx4 running on it. Parameters are Ammonia .25 Nitrite 0 Nitrate 80.

 

[Kaykay101]

Forgot to add I do about a 50% water change every Tuesday and Thursday haven’t done today’s yet though.

 

[Kaykay101]

Picture of whole tank just completed water change.

 

[j.w]

@Kaykay101
Could be a tumor or could be dropsy if you notice it looking like a pinecone. I don't see that tho. Nothing much to do if it is a tumor. If tumor I usually just let the fish be and hope they live a good life the way they are and not in pain.

 

[Kaykay101]

View attachment 140699@Kaykay101
Could be a tumor or could be dropsy if you notice it looking like a pinecone. I don't see that tho. Nothing much to do if it is a tumor. If tumor I usually just let the fish be and hope they live a good life the way they are and not in pain.

Definitely not dropsy I've had bettas and livebearers with it. Thought it could have been a tumor, but was hoping it was something curable.

 

[WaterGardener]

I have one in my pond that looked like that. I thought it was a tumor. It stayed that way for several months, maybe a year, but that swelling somehow disappeared. It looks perfectly normal now. I have no idea what it was. Maybe eggbound?