Deeper barrier support usually means a coordinated plan: consistent parasite control, a diet that agrees with the dog, and targeted topical care that reduces surface microbes and removes allergens from the coat. Supplements can support normal barrier function, but they rarely overcome constant exposure to triggers. Essential fatty acids are one of the better-studied nutrition angles in canine atopic dermatitis, yet they work best when the rest of the plan is not fighting them (Bensignor, 2008).
Owners can create a “repair window” by simplifying variables for 2–3 weeks: same food, same treats, same shampoo schedule, and a written flea-prevention calendar. That makes it easier to see whether paws calm down, whether ear odor returns, and whether the dog sleeps through the night. If nothing changes, it is strong evidence that the itch driver needs medical attention, not more variety.