Boreal Dog Supplement Zinc 450gBoreal Dog Supplement Zinc 450g Zinc serves two broad functions: Enzyme Function and Protein Synthesis. Dogs need zinc for healthy coats and for normal pigmentation of the coat hair. Boral Palatable Zinc Supplement For Dogs contains ZINPRO from Zinpro Performance Minerals, a patented organic source of zinc for animals, made by linking the amino acid methionine with zinc to form a structure that can be absorbed directly into the bloodstream.