When Benjamin Browning (Chevy Chase) reaches Heaven, he is sent back to Earth as a dog by a man named Mr. Higgins. Higgins was the original name of the dog (1957-1975) who later became Benji. In this movie, the dog is played by Benji, the daughter of the original Benji.
The female dog Benji was apparently the only actress to ever refuse to do a scene with Omar Sharif, according to the official "Benji" website. It states: "Omar's acting style is so intense, Director (Joe) Camp reports, that Benji could feel his intensity, and freaked out every time Omar touched him. This broke Omar's heart, and he was afraid the dog hated him, which was, of course, not true. In the end, to get the scenes, Camp wound up putting on Omar's coat, and being his hands in the scene(s)."
The movie was notable for being the first Benji movie not to normally have for all ages General or Universal classification rating in various territories. The picture instead usually garnered the equivalent of a PG (parental guidance) rating when classified. Film critics noted the movie's more adult tone which included profanity and sexual innuendo, something which was not typical of a family or children's film. As such, this picture was, in a sense, the first Benji movie with "adult" content.
According to the official "Benji" fan-site, "Benji is the only American actor ever banned from England. The British had a six-month quarantine on dogs in place, when Joe Camp wanted to shoot this movie there. The film had to be shot in Canada and France. The river scene at the end of the picture with Benji and a cat, is supposed to be the Thames, reports Camp, but is actually the Seine, at that famous spot right across from Notre Dame."
According to Wikipedia, "outtakes and behind-the-scenes footage from this film were used in making the short feature Benji at Work (1980), a 30-minute documentary about the career of Benjean as a dog actor".
The trivia items below may give away important plot points.
After the film's first act, Chevy Chase is only seen in the movie intermittently. Outside of these scenes, Chase is heard and not seen, the audience hears him only through voice, represented by Benji, who embodies his character.