My 7 year old rescued Westie had black skin, yeast, allergies, bare skin, and swollen paws. Repeated flareups after vet care. Researched Nzymes. Their website alone has a ton of helpful articles and references that helped immmediately. I bought the skin care kit that lasts about a year for a small dog. Each week you add another supplement to slowly detox internally from yeast. By week 4 black skin is fading and showing hair growth. Nzyme customer service sends weekly email to help you stay on the program and replies to you.