In the book, "Summer of Fear" (1976) by Lois Duncan, Rachel's beloved pet was a cocker spaniel, however Linda Blair's affection for horses caused Wes Craven to have her pet be a horse instead.
After having a successful television run on both NBC and CBS as "Stranger in Our House", the film was re-titled "Summer of Fear" (the title of the source novel) and given a theatrical release in Europe.
As Wes Craven notes on the DVD commentary, this was Linda Blair's first film after running into some trouble with the law the previous year. It would be her final starring role in a television movie until she played Shelly Stoker in Monster Makers (2003).