One of the most important symbols in this novel is of course Candy's dog, which is used to foreshadow what George does to Lennie at the end of the story. Candy's dog is old, and stinks, and slowly dying. However, Candy is extremely reluctant to shoot him, even though it would be better for the dog because of the pain he is in, because of the length of their relationship and the love he has for his dog, as the following quote describes:
"Well-hell! I had him so long. Had him since he was a pup. I herded sheep with him." He said proudly, "You wouldn't think it to look at him now, but he was the best damn sheep dog I ever seen."
What is important to note is that when Candy says "I had him so long," this is almost exactly the same thing that George says when he talks about Lennie, striking a parallel relationship between Candy and his dog and George and Lennie. The animal imagery that is repeatedly used to describe Lennie presents him as being more of an animal than a human in some ways, and it is important to note that after Candy says to George that he should have shot his dog himself, it is George who shoots Lennie. The helpless animal motif in this novel is therefore developed through the use of Candy's dog.