Movie with a scene about a boy that stands up against a man and refuses to kill an injured horse

Man (maybe father) tries to force a boy to shoot an injured horse and gives him a gun. The boy (8 to 14 years old) stands up against the man and refuses to kill the horse.

I’m sure it’s not a western and also pretty sure that the horse or horses in general don’t play a big part in the movie it’s just the only scene i can remember.
I also think that a big part of the movie is about the boy as an adult but I’m not so sure about that.

Thanks everyone!