Sorry for my bad english in advance
When i looked out the window i saw my grey koi fish ( ghost koi ) i call it the one on thelast 3 slides dead in my pond so i picked it out and these marks were on his body, i am not a expert i just find koi beautifull so i am looking for some advice, the white one on the first 3 slides has had that orange mark for a long time but it has always been a orange bump so i thought that it was koi pox or carp pox but now when i took it out the pond and had a closer look i saw that the bump was gone and it has become a hole, when i took a sample under the microscope i didnt see anything move like a parasite but it was just a sky with stars, just shining small sprinkles, i dont really now what i gotta do now or what it is, because my fish have always been super healthy, especially the white one, very active and could eat very well, sorry for my bad english i am dutch but i cant really find a good reddit in dutch, if you want videos dm me, i would really appreciate if someone could help me, thank you