All varieties of koi carp are prone to this disease. The affected koi carps will lie at the bottom of the tank as if they are sleeping.
When u slightly knock the tank, all sleeping koi carps will wake up and swim in a random manner. During severe cases of this disease, mucus layer of fish will come out and water look like turbid.
Secondary bacterial and other parasitic infection is inevitable.
Treatement for this disease is very easy. Fish Dr.Anti Parasite is the medicine which effectively works against these blood sucking parasites.