Picture quality's not that good, but this is a good little 8-minute short from 1971:
http://archive.org/details/tobacco_krb77c00
As the webpage says,
"Narrated by Orson Welles, this documentary was presented by the Leo Burnett Advertising Agency to Philip Morris as a promotional piece for Marlboro cigarettes. It focuses on wild mustangs in the American West, particularly on their being killed for use as dog food."

