The reason for the decline of sense of smell after raising cats at home is related to local factors of nasal cavity or neurological dysfunction. Smell is a feeling. It involves two sensory systems, namely olfactory nervous system and nasal trigeminal nervous system. Smell and taste will merge and interact. Olfactory receptors are located on the nasal mucosa above the nasal cavity, which contains epithelial cells and specialized olfactory cells that support function. Smell is a kind of telepathy, that is, the feeling of chemical stimulation from a distance. In contrast, taste is a sense of proximity.