Effects of zinc and linoleic acid supplementation on the skin and coat quality of dogs receiving a complete and balanced diet

This study investigates what effect adding zinc to a final dietary concentration of 23.9 mg MJ(-1) and/or linoleic acid to a dietary concentration of 3.6 g MJ(-1) in a complete and balanced diet has on the skin and haircoat condition of adult dogs. All animals were fed for nine weeks on a standard diet followed by nine weeks on a supplemented diet. After each phase animals were quantitatively assessed with respect to the condition and function of their skin and coat. Dogs supplemented with the combination of zinc and linoleic acid showed a significant improvement in coat gloss (P = 0.05) and coat scale (P = 0.007) when compared to the control group of dogs receiving the standard diet. In addition dogs supplemented with either zinc alone or in combination with linoleic acid demonstrated a significant decrease (P = 0.05) in transepidermal water loss over the time course of the test phase. As far as we are aware this is the first reported research to show that supplementation of a complete and balanced commercial dog food with zinc plus linoleic acid can make significant and substantial enhancements of the skin and coat condition in dogs.