Adrenal disease is a rather common disease of the ferret. It is characterized by the presence of cancerous or non-cancerous growths on the adrenal gland. Typically, the left adrenal gland is affected more often than the right. Symptoms include, hair loss (alopecia) that starts above the tail and progresses up the ferret's back, weight loss, swelling of the volva in females, thin, irritated, itchy, flakey skin that may develop sores, aggressive mating behavior in males and possible lethargy. This disease usually affects ferrets at three to four years of age (but it can affect younger ferrets). If your ferret has any of these symptoms, take it to the veterinarian as soon as possible.