What Is The Name Of The Skin Disease That Turns A Dogs Skin Black And Makes All Of It's Fur Fall Out? What Can We Do For It?

I know that that happened to my dog and they told us it was allergies. There is a special dog shampoo that is medicated and you use that. You didn't say if there was an odor?? I know Llady also had this odor to her. But the shampoo the vet gave us helped. Also my aunts dog had the same thing and bathing with medicated shampoo from the vets office helped. Did you try anything like this?? If so I know of another dog lol and the owners used Palmolive dish soap and let it soak on the dog for 5 minutes used a mild conditioner and it help the dogs skin.