COAT DEFENSE® Canine & Cat daily Preventative Powder is effective for itch, odor, and yeast because it alters the terrain on the skin. It creates a dry, safe environment that makes it uninhabitable for pests (pathogenic microbes, fleas, mites) to take up residence on your pet. It is not a medication. Many pets find relief within 1-3 days. For those on antibiotics and/or steroids, or have otherwise been immune compromised, results and healing may take 1-2 weeks.