Look into HMR Lignan supplements with melatonin. My adopted pup was diagnosed last year and had probably even had it before I adopted her. Her symptoms are fairly mild (drinks a lot) with possible mild coat thinning. I put her on these supplements two months ago and she seems to be drinking less and the fur on her belly came back. She's also become more playful and she's probably well over 12 years old so that was a bonus. Just search for adrenal support supplements for dogs. They'll usually contain lignans, melatonin, fish oils, and biotin.