It is a newer med, but it is NOT an ick med...
(copied)
Amongst the newly discovered compounds that are "silver bullets" in ridding certain pet-fish diseases, Metronidazole, aka Flagyl is a shining star. With careful use it can quickly eradicate some of the deadly and debilitating protozoan complaints of freshwater and marine fishes. Particularly useful for hexamitosis (the causative organism in many cases of Head and Lateral Line (Neuromast) Erosion, or corrosive syndrome, and many gut infestations, Metronidazole does have a definite downside. It's prolonged or too-repeated use results in the death of stock from renal (kidney) failure.
Scientific Designation:
1-(2-hydroxyethyl)-2-nitromidazole
Uses/Symptoms:
Principally for internal (lumen) protozoans and the flagellate commonly associated with HLLE (Hexamita, Octomita), though is promoted for use against other protozoans (Cryptocaryon, Ichthyophthirius). These last are better treated in other ways. Some groups of marine and freshwater fishes might/should be treated prophylactically... coming either directly from wild-environs or culture facilities known to harbor standing parasite fauna. Signs of neuromast destruction (HLLE) are open-pitting of the head and lateral line pores of fishes... Internal flagellate complaints manifest themselves in lethargic behavior, sitting on the bottom, bloating, slow, labored breathing, a lack of feeding...
