To get a healthier coat, you could start with a higher quality food. Eukanuba is very high in grains and low quality meat sources. Both of those wreak havoc on the quality of the coat. Try something grain free or low in grain like Canidae, Wellness, Orijen, Merrick, or Innova. Canidae is the least expensive option of the lot, but Orijen is my personal favorite and what I would feed given the choice.