Pickering begins with a casual shrug of surprise, the kind of remark made over a garden fence. We are told that every dog descends from the wolf, and the speaker's first examples are comic: the Pomeranian's ears, the Tibetan spaniel's skirts, the Dalmatian's spots. Each breed gets a parenthetical exclamation, as if the speaker were pointing at fancy-dress costumes. The joke is gentle, but it sets up the poem's real argument. If these fluffy, ornamental creatures are wolves underneath, what happened to the wolf?
The second stanza answers with a sudden change of register. The chatty tone drops away and the wolf arrives in a list of sharp, physical images: eyes that glow red in the dark, limbs that leap above human height, howls that fill "the arctic emptiness." Then the list turns frightening. "Starvation that tears the throat of a child" is the bluntest line in the poem, and it is placed where we least expect it. Then comes "dentition," a cold, clinical word set beside "rips the flesh from the bone." The Latinate vocabulary makes the wolf sound like a specimen, which is part of the point. Nothing in this animal was designed to please us.
The third and fourth stanzas change method. Instead of saying what the wolf was, the poem says what it never did, repeating "No wolf" like a refrain. The wolf's absence of weakness is described through the dog's ailments: ulcers from sheepdog trials, lead poisoning from carrying a newspaper, overeating when left alone with canned meat. These are oddly specific, and slightly absurd, which keeps the poem funny while it grows sadder. Notice that each illness comes from a job done for humans, or from being shut in by humans. There is also a quiet pun on "developed." In the first stanza dogs "were developed from the wolf," an evolutionary word, and in the third stanza no wolf "developed ulcers," a medical one. The same verb covers both breeding and sickness, as if one led to the other.
The final stanza piles up the dog's domestic life: chasing sticks, living in a caravan, snuggling with kittens, being "longed for at Christmas / by little girls." Here the poem makes a neat reversal. In stanza two the child is the wolf's victim, her throat torn open. In stanza four the child is a dreamer who wants a puppy under the tree. The same figure has moved from prey to owner, and the animal has moved from threat to present.
The poem ends on "His Master's Voice," a phrase made famous by the gramophone advertisement showing a dog listening to a recording. Its effect here is cutting. The wolf's howl once filled the Arctic, and the dog now tilts its ear toward a human voice, even a recorded one. The word "Master" gives the game away: this is a poem about power as much as pets. The line also breaks off in the middle ("or cocked an ear at / His Master's Voice"), so the last two lines hang on the edge, like a dog waiting to be told what to do.
Formally, the poem is free verse with no rhyme and no fixed metre. The rhythm is that of speech, with plain syntax and a dry, understated manner. That suits its tone, which is hard to pin down. It is not simply sentimental, mourning a lost wild animal, and it is not simply mocking, laughing at pampered pets. The line lengths shorten in the last stanza, and the effect is of the wolf's wildness being reined in, one short phrase at a time.
What makes the poem worth reading is that it turns a familiar comfort into a question. Most of us think of dogs as lucky, and the poem lets us see their luck as a trade. They gained warmth, food and Christmas wishes, and they lost the dark, the howl and the independence that gave a wolf its dignity. By the end, the "surprise" of the title has changed from a fact about ancestry into a feeling about loss. The poem never tells us whether the bargain was fair, and it leaves that judgment to the reader.