how does the book war horse depict the trench warfare

Tench warfare was insane and brutal. One's chances of dying were far greater than living. It was dirty, senseless, and brutal both for humans and for horses. Men lived in rat infested trenches with little to no food. Perhaps the most unnatural part of trench warfare was the horses. Kind gentle animals forced into an environment of pain and violence. The horses did not understand what was happening. The situation was nothing short of Hell.