Adrenal disease, or hyperadrenocorticism, is a disease that affects at least 75 – 80% of the ferrets in the US. It occurs when there is a tumor or lesion on the adrenal glands, causing an overproduction of the hormones produced by the adrenal glands. Adrenal disease is most common in ferrets over the age of three, but in recent years, ferrets as young as ten or eleven months have been diagnosed. There are many common ferret ailments out there, but adrenal disease is by far the most prevalent. Therefore, we as ferret owners need to know as much as possible about it, so we can recognize and treat it in our own ferrets.


If your ferret has hair loss or hair thinning – at the base of the tail, on its feet, on its belly, in a obvious pattern, in a patchy appearance, anywhere – your first thought should be adrenal disease. There are multiple causes for hair loss in ferrets, but if you see hair loss, you should always consider adrenal disease as a possibility, especially if the ferret is 3 or older. However, while hair loss is the most common symptom, it isn’t always a symptom.

Unlike other diseases, there is not a standard set of symptoms that adrenal ferrets will always display. The range of symptoms that your ferret shows will depend on where the tumors are on its adrenal glands. The adrenal glands produce more than 50 hormones from different places on the glands, so the location of the tumor will affect which hormones are overproduced, which in turn determines which symptoms you will see.

Here are the various symptoms of adrenal disease:

  • Hair loss, either in a symmetrical pattern or patchy with no apparent pattern *
  • Thinning hair
  • Loss of appetite
  • Lethargy
  • Papery thin or translucent looking skin, sometimes with sores from scratching
  • Excessive scratching and itchiness
  • Increase in musky body odor
  • Excessive grooming of itself or other ferrets, including ear sucking
  • Sexual aggression and mating behavior in neutered males – with other ferrets, inanimate objects, etc
  • Swollen vulva in spayed females
  • Difficulty urinating for males – this is a sign of a swollen prostate
  • Weakness in back legs – usually seen in advanced or extreme cases
  • Increased thirst, increased urination
  • Weight loss due to a decrease in muscle mass, but with a pot bellied appearance
  • Enlarged spleen
  • Anemia, resulting from too much estrogen, in females
  • High blood pressure
  • Rapid heartbeat

* It is important to note that you may see partial or complete hair regrowth without treatment. This does not mean that your ferret is fine, it just means that the hormonal imbalances have balanced out again, probably due to a season change. The hormones will become unbalanced again, and hair loss will occur, usually more severe than before.

Always remember that you can see any combination of these symptoms – there is no set group of symptoms! I have had ferrets present with the typical hair loss, and some with just a little thinning of the hair on top of their knuckles. I had one ferret, Mojo, who had a full, lush thick coat present with difficulty urinating as his only symptom. The important thing is to keep an eye on your ferrets as they grow older, watching for any symptoms or odd behavior. The reason Mojo was diagnosed was because he kept running from litter box to litter box, which wasn’t in itself a sign of adrenal disease, but was odd enough behavior for me to schedule a vet appointment.


If your vet has a lot of experience with ferrets or if your ferret has the traditional hair loss, he or she may often be able to diagnose your ferret through clinical signs (symptoms). It is sometimes possible to feel an enlarged left adrenal gland if your vet knows where to look for it.

However, given that many ferrets never display the most obvious symptoms of hair loss, your vet may want to use the Adrenal Panel run by the University of Tennessee, often referred to as the “Tennessee Panel”, in possible cases of adrenal disease. This is a blood test that evaluates the levels of hormones and steroid production. The test is not always 100% correct, and has been known to result in false positives and false negatives.

You can also run x-rays and ultrasounds to help determine whether or not adrenal disease is present, but this can be misleading as well. Diseased adrenal glands can be normal in size and shape, and therefore an x-ray or ultrasound may not raise any concerns.

When it comes to diagnosis, if your ferret is displaying any of the obvious signs, it is often better to begin treatment than to spend money on expensive tests and other diagnostic measures. Ferrets can suffer from adrenal disease for a long time before actually showing symptoms, so no matter how you arrive at your diagnosis, it’s important to commence treatment immediately after the diagnosis has been made.


You have a few options for treatment of adrenal disease.

This is the most common treatment for adrenal disease, and is the only way to completely remove the tumor. It is also the most recommended treatment by most vets. The removal of the left adrenal gland is fairly easy to do for a vet that has experience with adrenalectomies. The removal of the right gland is somewhat more difficult, since it lies directly adjacent to the vena cava, the largest blood vessel in your ferret’s body, and requires a good amount of experience on your vet’s part. If you do choose to go the surgical route, you will want to discuss with your vet whether he or she would be comfortable with a right adrenal, and what would be done if that was the case. If the vet seems at all hesitant about the surgery, ask for a recommendation for a more knowledgeable ferret vet!

If your ferret has already had surgery to remove one gland and adrenal tumors develop in the remaining gland, you will want to talk to your vet about whether or not surgery is the best choice. Ferrets that have both glands removed may develop Addison’s disease, which is a severe or complete deficiency of the hormones made in the adrenal glands. This is not something that happens to every ferret, but it is a possibility. If you get both glands removed, you will need to have your ferret’s cortisol levels checked within three days of the surgery. Ferrets whose cortisol levels are not within the normal range (25.9 – 235) will need Percorten and Prednisone to survive. Ferrets with no adrenal tissue at all who are not maintained on the necessary drug regiment will go into an Addisonian crisis within 2 – 3 days, and emergency treatment must be given immediately.

Though surgery is the only way to rid your ferret of adrenal disease, it is important for you to know that there is risk involved with doing the surgery. If any microscopic piece of affected adrenal tissue remains, the tumor can grow back either on the same side, or the opposite side. There is always a chance that the ferret may not make it through the surgery, or it may not make it through the recovery period in the first few days after the procedure is done. As gone over above, Addison’s Disease is also a concern if it is the second gland to be removed. You will want to discuss these things extensively with your vet before making any decisions. Some ferrets are just not good surgical candidates, either due to age, health or both, and with these ferrets you will want to go the medical treatment route.

Medical treatment options are available in cases where surgery cannot be performed, either due to the health of the animal, the lack of an experienced vet, or the reservations of the owner. They include:

  • Lupron Depot injections
    You can use 1 month, 3 month and 4 month Lupron Depot. “Depot” refers to the fact that the entire dosage is released over the given time period. This means that your ferret will need to get this shot at the appropriate time for the rest of its life. Lupron may shrink the tumor in some cases, but in most cases where it is effective, it only affects the symptoms.Even if all symptoms cease, you must continue to administer the Lupron. Lupron is a synthetic version of GnRH (gonadotropin release hormone), and it works by desensitizing the pituitary gland, which stops the production of the hormones that are over stimulating the adrenal glands. So if you stop administering the Lupron shots, the pituitary gland resumes its normal function, and all of the problems start again.If you plan on doing surgery, but can’t do it right away for whatever reason, it is recommended that you start the ferret on Lupron in the meantime. This will hopefully prevent the disease from progressing any further, and at the very least will make your ferret more comfortable.If your vet does not currently have Lupron, he or she can call Professional Arts Pharmacy at 800-832-9285. They will sell single doses.
  • Melatonin Implants
    Melatonin is a natural hormone that serves many functions in your ferret’s body, one of which is to inhibit the release of GnRH. Less GnRH means that the pituitary gland releases fewer hormones, which means that the adrenal glands are stimulated less.Melatonin can be used in oral (liquid or pill) or implant form. While you can use oral melatonin, the success or failure of it depends on the time of day it is given. It needs to be administered exactly 7 – 9 hours after sunrise to mimic the natural release of melatonin. If given at this time every single day, oral melatonin is extremely effective. Unfortunately many of us are not home during this time. A more convenient way to administer melatonin effectively is to use Ferretonin, a melatonin implant. Implants last about 3 – 4 months, and provide a steady level of melatonin over that time period.I would not recommend that Melatonin implants alone be used to treat adrenal disease. You will probably see the best results if a combination of Lupron Depot and Melatonin implants are used.
    Lysodren (mitotane) used to be used a common treatment for adrenal disease, but it was found that Lysodren didn’t stop the stimulation to the adrenal glands and caused low blood sugar. This is a concern, as insulinoma and adrenal are often seen together, and ferrets with insulinoma struggle with low blood sugar already. Overdosages of Lysodren were also known to cause Addison’s Disease.Nizoral (Ketoconazole) is used to treat Cushing’s disease (adrenal disease) in dogs, which is completely different from adrenal disease in ferrets. In Cushing’s Disease, the tumor is on the pituitary gland. In ferrets, the tumor is on the adrenal gland, which has been over stimulated by the pituitary.Vetoryl (Trilostane) is also used in dogs with Cushing’s Disease, and increases the level of a hormone that is already quite high in adrenal ferrets. Giving this to an adrenal ferret would make the problem worse.Nolvadex (Tamoxifen) is an anti-estrogen medicine in humans. However, it actually has estrogen-like effects in ferrets, which would have a negative effect on many adrenal ferrets.


Unfortunately there are very few ways you can prevent adrenal disease. It is currently thought that the early neutering/spaying that is done at large scale breeders directly contributes to adrenal disease, and in most case the ferrets that you get will already be fixed. If they are intact, it is recommended that you wait until they are at least 6 months of age before getting them fixed. Adrenal disease is still seen in late alters, but it is not as prevalent.

Recent studies have shown that light cycles also contribute to the development of adrenal disease. Melatonin, as mentioned above, regulates the release of GnRH. GnRH affects how much the adrenal glands are stimulated. (Remember, adrenal disease is called “hyperadrenocorticism”, which means that the adrenal glands are over stimulated.) Melatonin is produced when the ferret is in total darkness. Most of our ferrets live in the same environment we do – natural daylight during the day, and several hours of artificial light in the evenings. This obviously shortens the amount of time the ferret is in darkness, thereby decreasing the production of melatonin. Less melatonin means more GnRH is released, which then over stimulates the adrenal glands leading to adrenal disease. A ferret’s optimal light cycle is about seven to nine hours of light and fifteen to seventeen hours of total darkness each day. This will allow it to produce the most melatonin possible.


So what have we learned?

  • Adrenal disease is the most common ferret illness, and occurs in 75 – 80% of US ferrets.
  • Adrenal disease occurs when the adrenal glands are over stimulated by hormones from the pituitary gland. The adrenal glands produce too many hormones, causing the symptoms we see.
  • Hair loss is the most common symptom, but is not seen in all cases.
  • Treatment for adrenal disease can be surgery or medical treatment, in the form of Lupron Depot and Melatonin implants.
  • Neutering/Spaying ferrets after 6 months of age and giving them natural light cycles can help to prevent the development of adrenal disease.

It’s important to add one more thought here – adrenal disease is very treatable in most cases. Not treating adrenal disease is condemning our ferrets to die when this doesn’t have to be the case. If you see signs of adrenal disease in your ferret, please get it checked out as soon as possible! Ferrets can live long and happy lives after they are treated for adrenal, and I know we all want that for our fuzzies!