Parasite, tumor, or normal?

[cmotaval]

I have a 4,000 gallon pond with about 50 fish. The fish are all acting normal but I noticed these bumps on one of the fish. I am not sure when they developed, but it must be within the last few months. I recently built a sand filter and had to perform multiple water changes while it was being built. I am hoping someone could tell me if this is a sign of parasitic infection, a stress reaction due to the water changes, or if this is something normal.
Thanks in advance.

 

[WaterGardener]

Those look like tumors to me. Some of my fish have them to different degrees. They don't seem to bother the fish, or at least they don't for years.

I had one fish that had them for several years, and was fine. He eventually stopped eating and seemed generally unwell and was euthanized. I have no idea if the tumors were a factor, or if the cause of his illness was something entirely different. There were no other apparent symptoms.

I don't consider them normal, but they aren't that unusual either with goldfish.

 

[Lisak1]

We've had several fish with the same warty, lumpy, growths. One developed a very large single tumor - it eventually ruptured and the fish died. The other one is still living happily in our pond. The guy we bought some of our fish from said the same thing - sometimes it happens, no idea why.

 

[j.w]

Mine too have gotten these bumps and I just leave them be and let them live out their lives. They can go for years like that acting perfectly normal.

 

[cmotaval]

Thanks everyone. Happy I don't have a parasite issue going on.

 

[Goldfishpond]

My Shubunkin fish had tumors all over we named her Cheeto she was almost 6 years old and finally died. They were also on her head & her eye covering her whole body she finally died. She couldn’t see and I think had one too close to brain or something. She lived happily until death.