Adrenal disease in ferrets is now recognized as a common disorder in American ferrets, although it is less commonly seen in other areas of the world. It is a disease of middle aged to older ferrets, with the most common sign being hair loss. The term adrenal disease (sometimes called Adrenal Associated Endocrinopathy, or AAE) encompasses a variety of related conditions, including adrenocortical hyperplasia (the most common type, a proliferation of adrenal gland cells), as well as both benign and malignant (cancerous) tumors. The adrenal gland produces a number of hormones including estrogen and its precursors, and the presence of adrenal disease result in over-production of some of these hormones, resulting in the clinical signs and symptoms.
Signs of Adrenal Disease in Ferrets
- Hair loss. This is the most common sign and usually starts around the rump and tail and progresses up the flanks and over the back and chest and abdomen (the head and limbs usually retain some hair). The hair loss often starts in late winter and early spring and can be progressive, or regrow and recur the following spring. In some cases the skin may be slightly red and itchy.
- Enlarged vulva in females
- Difficulty urinating in males (due to prostate enlargement)
- Other possible signs include:
- Thinning of skin
- Muscle wasting
- Increased aggression
- Marking (urine) and mounting behavior
If your ferret is exhibiting hair loss or any unusual symptoms, a trip to a ferret friendly veterinarian is a necessity. Diagnosis of adrenal disease is often based solely on clinical signs. However, a full work up is indicated, with blood work and x-rays primarily to rule out other conditions that may be present along with adrenal disease before treatment. In particular, insulinoma (very common in older ferrets) should be ruled out. Ultrasound can sometimes be used to confirm the presence of an enlarged adrenal gland, and sometime a veterinarian will even be able to feel the enlarged gland, especially on the left. Oddly enough, over 80% of cases occur in the left adrenal gland only, with about 15% of cases involving both right and left glands.
The treatment of choice is surgery to remove the affected gland. In cases where only the left adrenal is enlarged, removal of the entire gland is performed. If the right adrenal gland is involved it is usually only partially removed due to its anatomy (proximity to the vena cava, a large vein). Recurrence of the clinical signs is possible, however, at which point another surgery may be indicated, or medical management of the clinical signs may be an option.
Medical management is possible but usually a second choice, for example for ferrets that are quite ill or weak and therefore a poor surgical risk. Historically, the drug Lysodren® was used, but is unreliable in resolving symptoms and has potentially serious side effects. More recently a drug called Lupron® has been used with some success. In some cases it is ineffective, but is generally safer. Some other drugs are being tried as well (see the medical protocol published by Dr. Charles Weiss). The disadvantage of drugs over surgery is that the drugs simply control the symptoms without doing anything to remove the source of the problem. This is especially important because some adrenal tumors are malignant, so surgery should be the first choice if at all possible.