Freshwater Flukes are very wide-spread across the globe and are a common parasite of many species of fishes, including koi. They appear as both a body parasite and a gill parasite and are one of the main causes of fish ulcers. Unfortunately, gill flukes and body flukes are microscopic and not visible to the naked eye. Flukes attach to the skin or gills and feed on mucus or blood found in these areas of the host. Through the miniscule puncture marks from these feeding parasites Aeronomes and Pseudomonas can find their way in and effect the fishes skin causing sores or ulcers.
Flukes are commonly treated by the use of Praziquantel and ProForm-C.