Hi,
I just wondered if anyone can help me. My black moor goldfish (well is actually now gold, has changed colour over time) has a growth/tumour on his side by the beginning of his end tailfin on the righthand side. Is there anything i can do to help my fish? The growth has been there for a very long time and didn't seem to be giving my fish any hassel so i left it alone. It's only till recently the growth/tumour has become very large and now looks like it has blood/redness inside it. My fish is constanly nose down with it's bum at the suface of the water and rests there most of the time. I haven't put anything in the tank to help as i didn't want to risk causing more damage. Any ideas? My fish is about 4 1/2 years old. I do keep my tank clean with regular water changes.

Many thanks xx

The growth probably is some sort of cyst or benign tumor if he's had it for a while. A fish vet could remove it but, otherwise, there's not really anything that you can do. If the tumor has grown, there could be a bacterial component (like fish tuberculosis) or even cancerous cells which are pretty rare in fish. Or, it could be a cyst swelling with fluid. The blood vessels would then become more evident.

Can you post a photo?

It's a concern if the fish can't swim right and lays around. Aside from keeping the tank clean and well aerated, I suggest adding some aquarium salt to the tank at a tablespoon per 5 gallons. Salt helps with general health and feeling for fish. It won't cure the fish but may make things a little easier on him.

Good luck!