Mass on side of 2 Koi

[Mark Michaud]

Any clue what this is? Large mass on 2 fish. Otherwise healthy appearing. Thx

 

[Gemma]

Well if it's just a single pimple I don't think it's Pox, and because you have 2 fish with it, my guess is some sort of bacterial infection...not an expert though so lets see what the other members say

 

[Mark Michaud]

Thank you. It's fairly large. About 1-1.5 cm in diameter.