Sure, Shmoop likes dogs. They come in all shapes and sizes (some are even "teacup"-sized, OMG, cute attack), they fetch, they keep us company. What's not to like? That said, we're not sure how we feel about the pooch in this poem. First of all, this dog seems to have run off. Bummer. Secondly, the speaker thinks this dog has fled to some pretty unlikely places. The sky? Really? What's going on here? Read on to find out.
The dog doesn't even appear in the poem until halfway through the last stanza. When he does, it seems to take the speaker (and, likely, the reader) by surprise. And the speaker calls it "a dog," not the dog or my dog; so, Berryman is presenting the dog in the most general, unattached way possible. He seems to want the reader to have as much connection to the dog as the speaker does; this dog is just a dog like any other.
The dog runs off, "into mountains or sea or sky," leaving the speaker behind. It is in these lines that we get the sense this dog is more than just a four-legged friend. Since what the dog is doing is literally impossible, we know he's gotta be some kind of symbol.
While dogs can represent everything from fidelity to depravity, we think Berryman was using this dog to represent something more. A lot more. Everything, in fact. Berryman's dog represents all the things we come into contact with in our daily lives. Even when these things are no longer with us, right there in front of our little faces, our accrued memories of those things shape who we are. In a sense, how we experience the stuff of the world makes us who we are.
Think of it like this. When the dog leaves, the speaker is left with the essence of the dog, its happy doggy "wag." When we finish a great book, we still feel the presence of its characters in our lives. (Come on, Harry Potter fans, you know what we're talkin' about.) Incredible songs can be stuck in our heads on repeat, even though the actual notes of these songs have long since disappeared into thin "sky." Er, thin air. See, these experiences of our physical worlds are what mold our emotional lives; they make us who we are.
Now let's consider what elemnts of the physical world bore the speaker of this poem. They are all tangible things, like art and music and people. And, like we've just said, it's these things that shape who we are. So, what is the speaker really bored with? Not "great literature" or "valiant art." He's bored with the person these things have made him into; he's bored with himself.