The ‘Animal symbol’ symbolizes the primitive and instinctive nature of human beings, and has been psychologically important since ancient times. Among many animals, dogs, in particular, were originally wolves, but were the first to be domesticated by humans. It is an animal that people attach to and regard as a family member because it is absolutely obedient to and dependent on humans when they perceive humans as the leader. However, in most countries, the dog is an animal that has been recognized not only as a loyal, home-keeper, but also as a guide between the dead and the underworld and as a human companion. The reason is that although dogs have been domesticated and become new animals, they still have the instinctive characteristics of wolves. Infants in the early stages of their lives also have a time when they rely entirely on their mothers, similar to the characteristics of domesticated dogs. However, when a healthy attachment is formed, the baby is psychologically separated from the mother and self-development begins toward independence. However, if psychological independence is not achieved for some reason, similar to a domesticated dog, they become completely dependent on their mother and are swallowed up by their maternal mother, and they may become stuck in childhood dependence, causing difficulties in interpersonal relationships. In this case, our reason, guided by the instinctive energy of our inner dog, begins a healing journey towards independence. In this paper, among the many symbols of dogs, the dog as a symbol of loyalty, the dog as a healing animal, the dog as a guide to the unconscious, and the dog as a symbol of instinct and intuition were examined. In addition, the symbolic meaning of the dog discussed above was confirmed through the case where a high school client who was psychologically dependent on his mother while having sandplay therapy started a healing journey by using a dog symbolically to achieve attachment and independence.