The Call of the Wild falls into the categories of adventure fiction and what is sometimes referred to as the animal story genre, in which an author attempts to write an animal protagonist without resorting to anthropomorphism. At the time, London was criticized for attributing "unnatural" human thoughts and insights to a dog, so much so that he was accused of being a nature faker. London himself dismissed these criticisms as "homocentric" and "amateur". London further responded that he had set out to portray nature more accurately than his predecessors.
"I have been guilty of writing two animal stories—two books about dogs. The writing of these two stories, on my part, was in truth a protest against the 'humanizing' of animals, of which it seemed to me several 'animal writers' had been profoundly guilty. Time and again, and many times, in my narratives, I wrote, speaking of my dog-heroes: 'He did not think these things; he merely did them,' etc. And I did this repeatedly, to the clogging of my narrative and in violation of my artistic canons; and I did it in order to hammer into the average human understanding that these dog-heroes of mine were not directed by abstract reasoning, but by instinct, sensation, and emotion, and by simple reasoning. Also, I endeavored to make my stories in line with the facts of evolution; I hewed them to the mark set by scientific research, and awoke, one day, to find myself bundled neck and crop into the camp of the nature-fakers."
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"). E.L. 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.