The quote reflects a sense of loss and finality, emphasizing that something or someone precious, symbolized by "the Dog," is now gone forever. It suggests a moment of mourning or the end of a chapter, highlighting the irreversible nature of this departure.
In the context of Garth Nix's work, such lines often underscore themes of change, memory, and loss faced by characters in their journey. The quote encapsulates a poignant moment where a significant bond or presence has vanished, evoking feelings of sadness and reflection.