 The dog in the movie is a Sealyham Terrier named "Johnnie" and  Alfred Hitchcock (I) (qv)s own dog. The main male character is  also named "Johnnie" and this name was Hitchs original idea for the  movie title. Alfred Hitchcock (I) (qv) kept Sealyhams for many  years. In his movie _Birds, The (1963)_ (qv), Hitch walks out of the  pet store with Sealyhams on a lead.