Billy Ray Cyrus was not on Dr. Quinn Medicine Woman. It's Joe Lando who, during the heyday of the series, somewhat looks like Billy Ray Cyrus.
via kwout
On a side note, Billy Ray played the role of Dr Quint in the 2014 TV movie, Sharknado 2: The Second One.
See a comprehensive list of Billy Ray's acting credits in television and in movies on IMDb.
Dr. Quinn Medicine Woman depicts the trials and adventures of a female doctor in a small wild west town. Starring Jane Seymour, the program also featured Chad Allen, Erika Flores, Jessica Bowman and Shawn Toovey.
See Dr. Quinn Medicine Woman full cast and crew here.