An old movie my Dad talked about. (Horse, horse)

My Dad and his friend used to talk about a movie they once saw. I have an impression that it's an old movie (Perhaps black and white). They're both born in '61 so I guess the movie is from the late 60's/early 70's.

They described that a part of the movie was about a disabled child (Downs syndrome) who was locked in some kind of a basement. They described that the child had a toy which was a horse made out of wood. He would then scream "HORSE HORSE" while playing with the toy.

It may be set back to the Middle-ages or something.. I don't really know. The whole plot is that the parents was ashamed of their retarded child and would hide him/her.

I've been looking for this movie for a long time, so I'd appreciate it if anyone had any suggestions.

It sounds like something in The Shipping News.

__________________
It's what you learn after you know it all that counts. - John Wooden
My IMDb page

A mentally disabled child screaming "Horse! Horse!" can only be Kaspar Hauser. Given your timeline, the movie your father and his friend saw was presumably Werner Herzog's The Enigma of Kaspar Hauser (1974).