What did Enzo learn happens to a dog in Mongolia when he dies?

This is when Enzo steps out of the narrative. Enzo tells the reader of a dog in Mongolia. When a dog dies, they bury him high in the hills so nobody can ever walk on his grave. The master whispers to the dog that he wishes for the dog to return to life as a man, and then the dog's tail is cut off and put beneath his head.