Linoleic acid and zinc are the two most important nutritional ingredients for helping dogs maintain a healthy skin and coat. Research from the WALTHAM Centre for Pet Nutrition has shown that supplementation of linoleic acid and zinc at levels well above minimal requirements will lead to increased coat shine and gloss, and an increase in the hydration of the skin. Further research shows that the addition of each of these nutrients separately leads to small benefits; however, the benefit is much greater when these nutrients are supplemented together.