How does the book address the idea of loyalty and betrayal?

The chosen answer highlights a central theme in "The Call of the Wild" by depicting the depth of loyalty in relationships, particularly through the bond between Buck and Thornton. This relationship serves as a poignant contrast to Buck's experiences with other characters who treat dogs as mere tools for exploitation. Thornton demonstrates genuine care and respect for Buck, which fosters a strong, mutually beneficial bond. The other portrayals, where humans use dogs for their own gain without regard for their feelings, underline the idea that while some relationships can be built on love and loyalty, others are tainted by selfishness and betrayal. This rich interplay between loyalty and betrayal throughout the narrative reinforces the emotional weight of Buck's journey and highlights the complexities of these themes in the harsh realities of life in the wild.