One of my butterfly koi began to develop fin rot on tail and some ulcers after I found a fairly large piece of fin in bottom of pond. He would sit in one spot near the edge rocks away from the other fish. I had some large plastic flower pots upside down with arches cut for koi to hide - I suspect he got some damage when moving in and out of the pots so I removed the pots.
Followed advice on a koi site - anesthesized him with clove oil; and performed some cleanup using peroxide, iodine, denture powder, neosporin and liquid bandage. That was last week - he was getting around great and seemed back to normal activity wise. Eating as normal etc.
Went on vacation but prior I bumped salt to 1,500ppm and had a friend do double dose of metafix daily.
Looked at fish today and some of sores are healing it appeared. Also found another black looking ulcer in another koi.
Removed the initial sick koi today and attached pic. He has some additional rot on pec fins and ulcers are healing it appears but tail still looks bad. I also noticed these small yellow ish bumps on fins primarily. Rather than stress him further I removed a few of bumps with scissors and let him recover and back in pond.
Pic attached - I’m unsure if I should let him alone and see if things cure? Or if I should euthanize him - really prefer not.
Thoughts? Are the bumps koi pox or just healings from an infection or something else? Really don’t want any outbreak.
Did not remove the other fish with one ulcer.