Duncan never struck Rinty to get him to perform for cameras or audience, never gave him treats, but only held up his old squeaky toy, and then let the dog touch it after he had finished a given task.

FORBES: Booked Review: "Rin Tin Tin: The Life and the Legend"

The object of reward, with which Lee trained Rinty and prompted him to perform his amazing physical feats, was a small squeaky toy the dog had been given as a puppy.

FORBES: Booked Review: "Rin Tin Tin: The Life and the Legend"