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Anna, Pet Expert/Biologist
Category: Pet
Satisfied Customers: 11513
Experience:  40 yrs.: herps, pocket pets, rabbits, poultry, dogs, horses. Biology degree. Vet assistant.
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Ive got a Goldfish problem: (Our 10 yr old pond holds about

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I've got a Goldfish problem: (Our 10 yr old pond holds about 530 gal; pH and ammonia have always been spot on.) Our 7-8 yr old comet - she's about 10-12 inches in length - has a large pink spongy tumor-like mass on one of her gills; located just behind the operculum, I can't tell if it's attached to the gill, the operculum, or both. The mass is wide enough to prevent the gill from closing completely. I removed her to a hospital tank and began treating with Melafix and Pimafix as well as an elevated salt level. No other fish are displaying any symptoms. My Question: If it's not contagious, I'd like to return her to the pond. How can I rule out bacterial or viral? And, if it's a genetic or non-bacterial/viral tumor what can be done?


I'm sorry to hear your fish is having a problem. Some additional information will help me to answer your question.

Is the fish eating and behaving normally?

Does the mass seem to bother her - does she rub on things or swim lopsided?

does she gasp for air at the water surface?

Thank you.

Customer: replied 4 years ago.

She is eating and defecating normally. Doesn't seem to bother her - she's not rubbing etc.
She's not gasping at the surface.
Did the photo get attached?
I have a high res. photo on Flickr:

Thank you for getting back to me. Yes, the picture did attach, but I also looked at the one on Flickr. There's no way to be certain without having an aquatic vet examine and perhaps biopsy the growth, but it looks most like an actual tumor to me. If it were caused by gill parasites, Orca would be rubbling on things and probably having difficulty taking in enough oxygen.

If it's bacterial, the treatment you are now providing would help, but it doesn't look like anything bacterial I've seen, plus most bacterial infections cause other symptoms. Viral is a possibility. the most common virus in goldfish is carp pox. But carp pox growths are usually waxy and this doesn't look waxy in the photo. If it is viral, there is absolutely nothing you can do about it. However, your other fish would have already been exposed. Actually, most goldfish have been exposed to carp pox, but many ahve developed immunity. If that's what it is, most fish live healthy lives with it, unless the growths reach the point that they interfere with movement or breathing.

A tumor can be removed by an aquatic vet if it begins to bother Orca. This link will take you to a directory of fish vets if you decide to go that route:

Many goldfish live for years with benign tumors. If it's cancerous, surgical removal wouldn't offer a permanent solution.

Only you can make the decision about what to do, but I'll give you my input. If this were my fish, I'd continue the full course of treatment with Melafix, Pimafix and salt. If the growth doesn't change during that time, and Orca develops no more symptoms, it's probably safe to put her back in the pond. Of course, there are no guarantees because nothing is ever certain with any living creature, but I'm inclined to think this is a tumor. If she is a very special fish to you, you may want to consult a vet.

If you have more questions, let me know by clicking on REPLY. I hope the growth will not cause any problems.

Anna and other Pet Specialists are ready to help you
Customer: replied 4 years ago.


Thanks for that input. I'll continue as you suggest and get her back in the pond ASAP. She has had enough trauma.



You're welcome, Dennis. I hope all goes well.

Thank you!