Ringworm Science Reports Anyone Have Experience In Malamute Hair Loss?

Anyone have experience in malamute hair loss? - ringworm science reports

Hello, my friend has a pedigree malamute castrated male of 4 years has gradually lost patches of hair in the last few years. His hair is dry and boring and a small amount of dandruff, bald spots relate to different parts of his body, and not regrowth
no infection, no color, it is a diet of high quality (food science and did not try before) licking or chewing on the skin, not scratchy. He saw several vets on this issue and even went into the middle of veterinary specialists, a dermatologist with no success in diagnosing the disease to be seen. The next step is to do a skin biopsy that anesthesia just curious if anyone has seen or experienced this problem or suggestion required?
As mentioned above, which has seen several vets, and have tried various treatments, so there is nothing obvious as dermatitis, lichen, or an infection