What I find interesting in Chapter Eighteen is the way that Dorian Gray is identified with the hunt, as indeed, he has become an animal who is trying to escape being tracked down and killed. Let us remember that in Chapter Seventeen he has seen the face of James Vane watching him, clearly with malicious intent, wanting revenge for the way that Dorian treated his sister.
Interestingly, we see Dorian for the first time in icy winter - the first scene of the novel took place in summer. This is also the first time we see Dorian in anything resembling a natural landscape, and he seems like a hunted animal gone to earth. Note how Dorian tries to save the life of the hare, being "strangely charmed" by its graceful movement. Important to note and focus on is Dorian's judgement on hunting:
"The whole thing is hideous and cruel."
Interestingly, Dorian acts as a mouthpiece for Wilde's own thoughts about hunting, but we need to recognise that Dorian's compassion for hunted things as expressed in this Chapter springs from the fact that he is one of them himself. And, as he is well aware, the hounds are closing.