A dog offers a devotion that is constant, single-minded, uncritical and impossible to corrupt, because that is simply what dogs do. Someone who has searched for years for an ideal companion among people and never found one may find it where they never expected to look.
Loving an animal on its own terms means facing its thoroughly physical world, including its smells, its toilet habits and its mating, rather than dressing it up as a little person. This is anthropomorphism in reverse: instead of making the animal human, the owner learns the animal's own concerns.
Taking responsibility for another creature's happiness is often awkward, erratic and undignified work done without expertise. The bond is built through that fumbling but stubborn effort to give the other a good life, not through any skill.
Even the closest companion stays partly unknowable, with its own tastes, wildness and dignity that never fully open to us. This strangeness lies at the heart of all relationships, and loving well means accepting it rather than explaining it away.