Many folks think dog 'food' is an improvement, ignoring canine dietary evolution.
A few months ago we switched our dogs from standard bags of dry dog food to a diet formulated by a local breeder/kennel. From their recipe, we mix up a daily batch consisting of boiled ground chicken, shredded carrots, active yogurt, protein powder (mostly fish meal), powdered shark cartilage, sunflower oil, Grape Nuts(tm), hard boiled eggs, a couple scoops of high-quality kibble, and enough beef or chicken broth to make it suitably moist.
The dogs go nuts over it, it's cheaper than premium kibble, and just in the six weeks or so they've been on it, their coats are very noticeably more smooth, soft, and shiny.
The German Shepherds at the breeder, which have been fed this diet all their lives, are so sleek and shiny that they practically glow in the dark, and are very muscular and *huge*, like Arnold Schwarzeneggers of the dog world.