Zinc is a mineral that is deficient in most dog's diets. What does zinc do? Well, it would probably be easier to list what zinc does not play a role in. Zinc is an essential nutrient needed for stabilization of cell membranes, reproduction, insulin storage, immunity and skin health. Dogs who are deficient in zinc can display some of the following symptoms: dull coat, dry scaly skin and a compromised immune system. We use a highly absorbable form of zinc called zinc methionine. Methione is an amino acid and cells love it. A zinc atom is bound to the methionine molecule so when the cell absorbs the methionine, the zinc gets absorbed right along with it to speed the passage of both through the cell walls.