The Call of the Wild falls into the genre of animal fiction, in which an animal is anthropomorphized and given human traits. In the story, London attributes human thoughts and insights to Buck, so much so that when the story was published he was accused of being a nature faker for attributing "unnatural" feelings to a dog. Along with his contemporaries Frank Norris and Theodore Dreiser, London was influenced by the naturalism of European writers such as Émile Zola, in which themes such as heredity versus environment were explored. London's use of the genre gave it a new vibrancy, according to scholar Richard Lehan.
The story is also an example of American pastoralism—a prevailing theme in American literature—in which the mythic hero returns to nature. As with other characters of American literature, such as Rip van Winkle and Huckleberry Finn, Buck symbolizes a reaction against industrialization and social convention with a return to nature. London presents the motif simply, clearly, and powerfully in the story, a motif later echoed by 20th century American writers William Faulkner and Ernest Hemingway (most notably in "Big Two-Hearted River"). Doctorow says of the story that it is "fervently American".
The enduring appeal of the story, according to American literature scholar Donald Pizer, is that it is a combination of allegory, parable, and fable. The story incorporates elements of age-old animal fables, such as Aesop's Fables, in which animals speak truth, and traditional beast fables, in which the beast "substitutes wit for insight". London was influenced by Rudyard Kipling's The Jungle Book, written a few years earlier, with its combination of parable and animal fable, and by other animal stories popular in the early 20th century. In The Call of the Wild, London intensifies and adds layers of meaning that are lacking in these stories.
As a writer London tended to skimp on form, according to biographer Labor, and neither The Call of the Wild nor White Fang "is a conventional novel". The story follows the archetypal "myth of the hero"; Buck, who is the hero, takes a journey, is transformed, and achieves an apotheosis. The format of the story is divided into four distinct parts, according to Labor. In the first part, Buck experiences violence and struggles for survival; in the second part, he proves himself a leader of the pack; the third part brings him to his death (symbolically and almost literally); and in the fourth and final part, he undergoes rebirth.