Anne-Marie, from All Dogs Go to Heaven (1989), was replaced with David, an 8 year old magician wannabe, due to Judith Barsi's fatal tragedy back in 1988, as the producers decided not to recast Ann-Marie in further All Dogs Go To Heaven franchise since she became a dedicated character of the ill-fated actress.
Although it is never revealed there's a common fan theory that David's biological mother who passed away some time before the beginning of the film is Anne Marie the little girl from the 1st film.
Despite being a sequel to the original film directed by Don Bluth, the film can be noted for having several contradictions from its predecessor: *In contrast to the previous film, where it took place in the year 1939 in Louisiana, this film takes place in the year 1995 in San Francisco, 56 years after the first film. *Instead of Charlie not being the character he developed into at the end of the first film, he is once again the self-absorbed and careless dog that he was before meeting Anne-Marie. It is very likely that this film, its sequel tv show and film, are complete alternates from the first film, and from one another.
During his Villain Song, Red puts Carface in a barber's chair and proceeds to shave him, a clear Shout-Out to Sweeney Todd: The Demon Barber of Fleet Street. George Hearn, who voiced Red, was also one of the many actors to have played the titular barber in one production of the musical.