Bewitched S01 E03 It Shouldn't Happen to a Dog

"Witches are people too!"

When Darrin's alcoholic and lecherous client Rex Barker makes a pass at Samantha, she decides to teach him a lesson by turning him into a dog. The dog runs away, but Samantha eventually gets him back. When Rex makes another pass at her, Darrin knocks him cold. Rex does wind up giving Darrin his account.