What TV show starred a series of six female impersonators during its 17 year run?

Lassie.

The screen Lassie was not only a superbly trained animal actor but a skillful female impersonator as well. Some may be scandalized that the original Lassie was actually a clever male collie named Pal. Under trainer Rudd Weatherwax, Pal beat out 300 curs to star in MGM's screen version of "Lassie Come Home" (1943).

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