Anyone remember this horse story?

[Clawdy]

So long ago can't remember name or author,have been wondering about it for years. A children's picture book about a boy on a farm with a beloved carthorse. The boy dreams all the time about he and the horse flying. At the very end,the horse dies,and the last page is the boy watching in wonder as he sees the horse's spirit flying up and up into the sky.Written probably in the sixties I should think?

Is it Ludo and the Star Horse? I haven't read it but dd has it & I remember her describing it as something like that.

Ah, sorry, just realised yours is a picture book - Ludo is a novel.

Thanks,Takver,yes, a friend did suggest Ludo but unfortunately it's not!