How does the author use foreshadowing in the novel, Tender is the Flesh?

The puppies that Marcos finds in the serpentarium are a symbol of innocence, as being with the puppies helps Marcos to experience a pure joy he has not felt since his son's death. He later witnesses a group of teenagers killing the puppies. Their violent act reveals the ways in which the Transition has stripped the world of its innocent purity. At the same time, this scene foreshadows what Marcos will do with Jasmine and her baby at the novel's end.