Odd article explaining all of the tricks and techniques used by trainers to get their animals to perform in movies without using vocal commands.
Mechanical Cues DIRECT Animals in the “BARKIES”
by WALTER A. RASCHICK
When the talkies came in, directors of animal pictures faced a new problem. Before the super-sensitive mike, vocal commands were impossible, so other means of giving “stars” their cues had to be devised. In this unusual article you are taken behind the scenes and shown how directors utilize ingenious mechanical gadgets to make animals perform with keen intelligence before the camera.