What was the problem in book horse and his

Please provide me with the full title of the book you are referring to. "Horse and his" is not a complete title, and I need more information to understand what problem you are asking about.

For example, is it:

* "The Horse and His Boy" by C.S. Lewis?

* "The Horse and His Boy" by Madeleine L'Engle?

* "Horse and His Boy" by another author?

Once you tell me the full title, I can tell you about the problem in the book.