Koi

[The Willows]

Hi everyone
I have a problem with my koi. It appears to have raised white blisters on it's back.
Can anyone tell me what it is and how to treat it.
Thank you

 

[j.w]

@The Willows
Looks like a fungus to me but I am no fish doctor.

 

[Mmathis]

Hello and welcome!

Sorry you koi has a problem! I don’t know anything about fishy diseases, so take my “diagnosis“ with a grain of salt (not literally — I’m not recommending adding salt, oh my!). My goldfish get something like this and it’s a “carp pox,” a viral infection related to herpes. There is no cure for it, and other than aesthetics, it isn’t harmful. Also, with good water quality, it also isn’t contagious.

NOW, if it isn’t carp pox, there are others things to look for. If you give us a description of your pond, gallons, water parameters per testing, filtration, number of fish, any changes recently made to the pond, and other symptoms or behaviors that you have noticed...this kind of information can be helpful in pinning it down.

 

[The Willows]

Hi I did a 90% water change and cleaned all the filters. I have a UV light and the pond is approx 3000 gallons. Approx 20 fish. 5 koi and the rest goldfish.