The evolution of the human-animal bond, combined with the rapid development of sophisticated diagnostic and medical treatment technology in veterinary medicine has made the geriatric pet a common household phenomenon. Pet owners and veterinarians are now aware that behavioral changes in senior animals are not just "old age" and that therapies exist to both improve quality of life and increase longevity. This section aims to address behavioral signs associated with sensory and cognitive decline in dogs and cats and to provide current information on treatment options.