Nutra Cal is when you have young pups that are prone to sugar level drops. Nutra Cal can quickly raise those levels to avoid hypoglycimia (I am murdering the spelling). By feeding your chi small meals thru the day it wont be necessary so much. I am certain each dog is different. I do give Kemo supplements either from Vita Dog or my own. I am into that for myself so I want Kemo to live as long as possible. Having a strong immune system will ward off lots of parasites and diseases. 