Michigan Department of Conservation
Institute for Fisheries Research Report No.1751, 1968
Investigations on Fish Parasite Control: I. Di-n -butyl Tin Oxide as a Vermifuge on Eubothrium crassum (Bloch, 1779) in Rainbow Trout

John G. Hnath

Abstract.-Rainbow trout (Salmo gairdneri) at the Harrietta State Fish Hatchery have, for a number of years, been infested with the tapeworm Eubothrium crassum. Di-n-butyl tin oxide was tested as an anthelmintic on this intestinal tapeworm, both in the laboratory and in a raceway. The drug was found to be 100 percent effective in removal of the worms, when mixed with a commercial pelleted diet. The total dose level was 500 milligrams per kilogram of body weight of fish; it was fed over a three-day period (one-third of the total dose, per day).