About 1 1/2 weeks ago we had one of our koi babies taken from us by a heron. It was devastating but amazingly enough we only lost one. A few of the gold fish and one other koi has a scrape on it. Everyone is healing well. Yesterday I noticed one of our butterfly koi, Falcore, had white weird stuff going on with his tail. Otherwise was acting normal. Today he is a little lethargic but when food is thrown in he eats. It seems the white has advanced today to the top fin and further up the tail. I cant tell if it is residual from injury or tail rot. With no one else exhibiting signs of disease and even one koi healing beautifully from a skimmer incident I am surprised if it would be rot. Any thoughts? Not sure if I should take him out and treat him in quarantine. Side note, we added 5 new koi withing the past month.
Sorry about picture quality. He is the all white genetically mutant butterfly.lol