Adrenal Gland Disease – Hyperadrenalcorticism

By L. Vanessa Gruden, 2010

Adrenal gland disease is a common illness seen in ferrets as they age. Normally it begins to show at late middle age (4-6 years) but it can occur in ferrets as young as two. The disease starts as enlarged glands, progresses to a benign cancer, then to a malignant one.

“Cancer” is always a scary diagnosis, but there are a lot of different cancers that act more, or less, quickly. Adrenal cancer is not immediately life-threatening. It is slow-acting and rarely metastasizes (spreads to other organs). Since it does not effect more sensitive organs such as the stomach and intestines, is not believed to be painful. More immediately dangerous can be some of the symptoms, which we’ll discuss below. But veterinary medicine now has several methods of treatment that can assure a ferret living with adrenal problems a good quality of life.

What are Adrenal Glands & What Goes Wrong?

Located near the kidneys, adrenals are small glands that help regulate hormones, especially the sex hormones estrogen and testosterone. Just because they have been altered (testes or uterus/ovaries removed) does not mean the signals from the brain to produce these hormones have stopped. A ferret’s breeding season is tied to the amount of daily sunshine. In an intact animal, the ovaries or testes would receive the signals and as they are bred or the light changes, would signal the brain to stop. Without those organs, all the signals go to the adrenal glands and they may begin to secrete excessive amounts of sex hormones.

It is unclear what exactly causes the malfunction, but theories suggest that either the early altering of baby ferrets (kits) may be a cause or the artificial light patterns in which most pet ferrets live in our homes.

Symptoms

All the sexual hormones being released effectively make the animal’s body believe it is going into season even though he or she has been neutered or spayed. So most of the symptoms are the same that would be seen in a breeding animal. The problem is, they don’t stop and progressively grow more disruptive.

Hair Loss: There is a distinctive pattern of hair loss. It will begin at the base of the tail and progress up the back, along the tail, and may result in the ferret eventually with only a few tufts of hair on their head and feet. You may see seasonal re-growth, only to see the hair disappear again and the loss become progressively worse. While hair loss is the “classic” adrenal symptom, the disease CAN be present even with a full coat of fur! Additional symptoms that suggest adrenal disease are as follows:

Behavior Changes: Males previously peaceful may become aggressive, biting or mounting others. Females may act “motherly” – excessively grooming and licking other ferrets.

Swollen Vulva: As with an intact female readying for mating season, an adrenal ferret’s vulva often swells. The potential for infection or aplastic anemia such as you would see in an unaltered female not bred becomes likely.

Enlarged Prostate: For males, swelling of the prostate may occur, which decreases the flow of urine. It is extremely dangerous – it will cause straining and eventually a complete blockage. Without immediate medical intervention the animal will suffer considerable pain and die within days. It is possible to bypass the blocked urethra by creating a hole along the tube leading from the bladder to the penis, which runs along the male’s lower belly. This surgery, called a perineal urethrostomy, is far easier than trying to catheterize a ferret’s small penis. While care must be taken to make sure the incision doesn’t close as it heals, this surgery can be quite effective and the animal will usually learn to control the flow of urine through the new outlet.

Thin Skin: The skin may become more sensitive and dry. It may become itchy and scratch or bruise easily. There might be changes in skin color, dullness, or appear translucent.

Other Symptoms: You may see changes in activity or weight or muscle loss. These are secondary symptoms that can also point to other illnesses, so are not necessarily a result of adrenal disease.

Diagnosis

Currently there is no definitive test for adrenal disease. While blood analysis may help identify other health problems that may be present, they will not diagnose adrenals. The use of ultrasound is problematic, as there may not be enough enlargement of the gland to be seen. An experienced vet may be able to feel an enlarged adrenal gland through a physical exam if the gland is very large. Exploratory surgery offers a better chance of diagnosis as the surgeon can visually check the color and texture of the glands but, of course, can be expensive. Generally, the set of symptoms described previously are enough to confirm a diagnosis.

Treatment

The only actual “cure” for adrenal disease is to surgically remove the diseased gland. Of the two, the left gland is the easiest to remove and often the one the veterinarian will try first. The right gland is very close to a main artery (the vena cava) and may be so wrapped up in blood vessels that is impossible to safely remove. A few problems remain:

First, it is expensive – often prohibitively so. Next, the disease may already be affecting both glands, and while there is still discussion about whether a ferret can do well without both adrenal glands, most doctors are reluctant to remove them at once. Third, even if one gland seems fine, the chances of it remaining healthy are poor. You may see symptoms recur within a year as the other gland enlarges. If the animal also has insulinoma (a cancer of the pancreas), as is common, it may suddenly significantly worsen after removal of the diseased adrenal. And last, if the animal is elderly and/or has other health issues, the anesthesia itself poses risk.

Drug Therapy

It is important to keep in mind that no current medicine will cure adrenal disease. Medications currently in use will only stop the progression of the illness or alleviate related symptoms. Both drug therapies are not 100% effective and may either not effect the illness at all or their effectiveness may decline over time.

Lupron™ (leuprolide acetate) is a human medication that suppresses the release of hormone signals from their origin so they never begin to effect the adrenal glands. Depending upon which version of the drug is used, it can either be injected monthly or every 4 months. If Lupon is effective, there may be a reduction in symptoms within 2-4 weeks but increasing dosages may be needed as the animal’s body becomes resistant to the drug. Lupron is not an inexpensive medicine and has a short shelf life. A veterinary clinic may be able to reduce the cost if a number of clients are using the drug and they can purchase in bulk.

Melatonin is a natural hormone that also reduces production of hormone stimulant. It can be used alone or in combination with Lupron. It is possible to administer melatonin orally – liquid forms can be purchased online – however for maximum effectiveness it should be given on a strict timetable. Melatek LLC has for sale to vets an implant , Ferratonin™, with a time-release system to provide better regulated dosages. The implant is the same size as a microchip (about the size of a grain of rice) and lasts for 4 months. The cost is quite reasonable and implants can continue to be inserted without removal of the “spent” ones. Response to melatonin can take several months, depending on where the ferret is in their seasonal coat change cycle. It’s effectiveness is inclined to lessen over subsequent administrations, or it may not be effective at all.

At our shelter, we are cautious about approving surgery for elderly animals with adrenal disease. We simply have not seen the cost outweigh the risks, and as a shelter, we are responsible for the wellbeing of a great many other animals. Our regimen for older animals is to begin with the least expensive treatment, melatonin. We may progress to Lupron if necessary and funds allow.

Treatment is a choice each individual must discuss with their veterinarian and decide upon themselves. As the disease itself, as previously mentioned, progresses slowly, it may be possible to delay the most expensive options to save funds to proceed. While adrenal disease should never be ignored due to the potentially deadly accompanying symptoms, management can make the animal comfortable for up to 2 years.

Prevention

One theory recommends you try, as much as possible, to keep your pets in natural light only. An option is to mimic seasonal daylight hours with lighting – turn on lights when the sun comes up and turn them off when it sets. Unfortunately, given most people’s daily work schedules, they usually need to be able to interact with their pets after dark, especially in winter.

A belief exists that obtaining a ferret unaltered directly from a breeder and altering them at puberty (about 6 months of age) reduces the chances of developing adrenal disease. However, in our experience, we have not seen this correlation. We have sheltered ferrets coming from breeders that were only altered at 3 to 5 years old and seen them also develop adrenal disease.

Some veterinarians are now recommending that all altered ferrets under the age of 1 year receive a Lupron injection the first breeding season after puberty and once a year afterwards. The theory is that it will stop the pituitary gland from even beginning to release the hormone signals that result in the disease. Under this treatment, the current protocol recommends adult altered ferrets have regular hormone checks and, if hormones are elevated, receive Lupron until the levels drop. Current studies have shown success with this protocol, however, the cost may be prohibitive to the average owner.

To sum up: Awareness is key. Knowing what the symptoms are of adrenal disease is the first step. Keep a watchful eye on those symptoms that may require immediate medical care. Understanding how the illness works and the treatments available will help you discuss the best options with your veterinarian. We wish your pet ferret the best of health!

Thanks for information combined into this article go to:
Ferret-Universe.com, Adrenal Disease article.
Ferretsanonymous.com, Adrenal Disease in Ferrets, by Sari Kanfer, DVM.
Heidihoefer.com, Adrenal Disease in Ferrets, by Heidi Hoefer, DVM, ABVP