Yellow goldfish with fin problem!

[catalina76]

My daughter's favorite goldfish is dying... or so I think it is.

It was swimming in a weird way tonight and its upper fin is completly down (not like him usually).

I took a picture (quickly since DD was sleeping) and you can clearly see his upper fin is down.

Is where anything I can do to help the little one?? We lost another goldfish (a chubby one) 3 days ago (it got caught in the aspiration)....

 

[mshill90]

We need to know much more in order to help...

What are the water parameters?
Water Temp?
Tank Size?

What are you feeding, and how often?

What is your upkeep on this tank?

Tankmates?