Betty, You did not mention the age of your ferret, but my first suspicion would be adrenal disease. The balding pattern - starting at the base of the tail and progressing upwards is a good indicator -- though it has also started at the shoulders and worked down to the tail in past experiences as well. I would search for a vet in your area that is familiar with adrenal symptoms and treatment. Chances are if the affected adrenal gland is removed he will be just fine and regain his coat. If left unattended too long the gland could eventually effect other organs. So check this out! Fondly in ferrets, Alicia a shelter Mom [Posted in FML issue 1912]