Oral pharmacological treatments for parasitic diseases of rainbow trout Oncorhynchus mykiss. I: Hexamita salmonis.

Various drugs were evaluated as regards efficacy for the treatment of Hexamita salmonis infection in rainbow trout. The results confirm the efficacy of nitroimidazoles: infection was completely eradicated not only by metronidazole (which has been recommended previously for the treatment of hexamitosis), but also by benznidazole, ronidazole and secnidazole, which have not been assayed previously. The non-nitroimidazoles albendazole, aminosidine, diethylcarbamazine and nitroscanate also completely eliminated infection. The remaining non-nitroimidazoles tested (amprolium, bithionol, febantel, flubendazole, levamisole, netobimin, niclosamide, nitroxynil, oxibendazole, parbendazole, piperazine, praziquentel, tetramisole, thiophanate, toltrazuril, trichlorfon and triclabendazole) were not effective.