Between The line question: How does Lenny and Candy's dog relate?

In most of the novel, Lenny is constantly relates to a dog, or another animal, like Lenny's dog. As the story progresses, all the men at the ranch continuously tell Candy that his dog "Ain't no good to himself or no one else", therefore, getting shot in the head to end his misery. Lenny is also told numerous times that he is also not good for himself oir no one else, resulting in his death with a bullet in his skull. These characters are also companions to two men being Candy and George and are the other half of the men as well when it comes to dreams and goals.