Colombo Lernex Pro is an improved version of Colombo Lernex, developed for the treatment against resistant flukes on ornamental fish. Lernex Pro is based on the most recent scientific knowledge and contains high quality antihelminthics like Nitroscanate and Flubendazole, against which no resistance has been built up yet. Therefore, Colombo Lernex Pro is effective against resistant skin flukes (Gyrodactylus) and gill flukes (Dactylogyrus). The presence of these parasites can only be determined with a microscope.