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Whirling disease of trout, caused by Myxosoma cerebralis, was diagnosed in 1966 for the first time in rainbow trout (Salmo gairdneri) from California and Nevada hatcheries. In 1969 the first incidence of this disease in cutthroat trout (S. clarki) was reported in Nevada. To date these have been the only confirmed cases of whirling disease in western United States.
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Yasutake et al. (1970) studied this question.
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