The scales show a lifting of partial or whole scales and they become raised like pine cones. If these scales are pushed, pus will ooze out and, as the disease progresses, the eyes will protrude. It is known to be caused by bacteria in the blood vessels or organs. Occurring mainly in the spring season, it can be caused by feeding oxidized high protein old food, plus a contaminated pond.

It is very difficult to treat a Koi with a full blown infection, but, if treated early enough, it can be saved with antibiotic injections.

*Information on this page is an excerpt from "KOI" by Grant Fujita, available at the AKCA online bookstore.