why did u make the dog abused

Hey, I`m a student and I was wondering why did u have to make the dog abused, I love the book, by the way, I just don`t understand that like I get that people get abused, but that doesn’t make any sense to me.

Judd was a miserable, angry man who didn’t know how to deal with his anger.  He himself was mistreated when he was a boy, and many people in this situation grow up to abuse anyone or any animal that is weaker than they are.  They are trying to prove that they are no longer a victim–that they are in control.  If Judd had children, he would undoubtedly have mistreated them.  Once he experienced the kindness and concern of Marty and his family, he began to change.