Strange internal growth

[spkennyva]

About 1 year ago we noticed a koi with a growth on the left side of its body (roughly across its body from the vent). This growth has gotten substantially larger, and is now very noticeable. Initially, I thought that it might be some type of cancer, as the fish is eating, but very emaciated. However, recently I noticed two other fish are now showing the exact same type of growth. As of now these two additional fish have not lost weight, but the growth does appear to be getting larger.

Any thoughts? Are there any type of internal parasites that effect koi and present this way?

[ademink]

Good morning - if you can provide photos, that would be very helpful.

[spkennyva]

Thank you for responding.

Pictures will be difficult at this time of year. My pond is covered with a net and getting good clear pictures might be a challenge. I'll try to describe what I see a bit better. The fish with the most advanced case presents with marble sized internal growths pushing out its skin. There are no external growths present. The growth looks like maybe 3 marbles clustered together on his left side, again just about the same position as the vent, but definitely on the lower side of the fish - not the bottom. This is very noticeable! The fish is Doitsu and I think is male and has lost a lot of weight, but still is actively eating. The two newer cases are smaller growths and as of now they appear as a single internal bump, but on the same side and position as the more advanced case. One of these is a scaled butterfly, female. The other is only 18 months old, scaled, and sex is unknown.

I'll attempt to get a picture, but I can't promise anything. I definitely appreciate any help you all can provide.

[RichToyBox]

To my knowledge there are no internal parasites that would be large enough to create a visible bump. Visible bumps like this are generally cancer, or in the case of some females, egg impaction, but that is generally an overall swelling, not marble sized bumps/lumps.

[spkennyva]

About 1 year ago we noticed a koi with a growth on the left side of its body (roughly across its body from the vent). This growth has gotten substantially larger, and is now very noticeable. Initially, I thought that it might be some type of cancer, as the fish is eating, but very emaciated. However, recently I noticed two other fish are now showing the exact same type of growth. As of now these two additional fish have not lost weight, but the growth does appear to be getting larger.

Any thoughts? Are there any type of internal parasites that effect koi and present this way?

I managed to get a couple pictures of the growth today.

[RichToyBox]

My guess would be a tumor. Gravid females and egg impactions would be general swelling over the abdomen, with some areas possibly showing increased bulge due to muscle tone of the abdomen.

[spkennyva]

My guess would be a tumor. Gravid females and egg impactions would be general swelling over the abdomen, with some areas possibly showing increased bulge due to muscle tone of the abdomen.

Thank you!