In several independent films and literary fiction (e.g., Megan and the Stubborn Husky by L.T. Ryan), the dog represents the previous romantic attachment. The dog was "their" dog. After the breakup, the dog stays with the girl. Every time the new love interest touches her, the dog inserts its wet nose between them.

In paranormal romance, the dog is a familiar. The girl is a witch. Her romantic storyline with the vampire/werewolf is mediated by the dog, who hates the supernatural lover. The relationship becomes a trial by fang.

This forces the new hero to negotiate a truce. He must bring treats. He must wait outside while the dog sleeps on the bed. He must prove he is not threatened by a creature that loves her unconditionally.