In the first chapters, it is apparent that Lennie is a simple minded man who likes to pet things that are soft and delicate. George and Lennie are traveling through to the farm for work. They had to escape from the town they were previously at because Lennie had an incident with one of the women in the town. He was a rather large, frightening fellow. He went up to a young women because the beauty of her dressed marveled him. Just as he did with mice, he insisted on touching it. That is all. Because of her frightened screams, he grabbed onto the dress and did not let go out of fear and panic. This led him into much trouble and the townspeople to go after him. George took Lennie and they escaped the town. This is foreshadowing to the ending scene because once again, Lennie just had to have a touch and once again, led him to trouble that even George could not fix.
When Carlson insisted on killing Candy's old worn dog friend, it was foreshadowing to the final scene in which all of the men insisted on searching and killing Lennie. Although Candy deep down knew that his dog was beyond his years and was suffering day to day, it was hard for him to accept it and let go. His dog was his only true friend. The same is true about Lennie