Common Ferret Medical Issues

While ferrets are some of the most fun pets ever, they sadly have a much shorter life span than we would like. The average life span of a ferret is about 5-8 years. Now that doesn't mean your ferret can't live longer, there have been several cases of ferrets living to the ripe old age of 13 or 14. But unfortunately most ferrets will succumb to one of these illnesses long before they reach old age. Most previous ferret owners, when asked why they no longer have ferrets, say it because it is just too hard to keep losing them. Ferrets are like a falling star - they are beautiful and bright and bring joy to your life, but they fade out long before we are ready for them to.

Adrenal disease.  This is by far the most common disease we see in ferrets.  Adrenal disease is a hyperplastic disease of the adrenal gland, similar to Cushing's disease in dogs and people.  However, in Cushing's disease, the adrenal gland over produces corticosteroids.  With adrenal disease in ferrets, the adrenal gland over produces sex hormones.  The most common clinical sign that we will see is hair loss from the hair follicles weakening from the constant hormone stimulation.  In males, we can see more aggressive behavior, and in females we can see an enlarged vulva, much as if they were in heat, even though they are spayed or neutered.  With males we can also see an enlarged prostate which can potentially become life threatening if it interferes with being able to urinate. 

There are several treatments for adrenal disease in ferrets and one potential cure.  The only potential cure is surgery to remove the affected adrenal gland.  If the adrenal disease is only in the left adrenal gland, then the surgery is fairly uncomplicated.  However, if the adrenal disease has spread to the right adrenal gland, then the surgery is extremely complicated.  The right adrenal gland sits on the vena cava, the largest vein in the body, and with adrenal disease, it can actually grow into the vena cava.  The only way to effectively remove it is to be able to perform vascular microsurgery, clamp off the vena cava, remove the tumor, and sew the vena cava back shut.  Very few vets are able to perform this procedure.  There are alternatives such as cryosurgery and hemaclips, but they do not guarantee complete removal of the right adrenal gland.

The other treatments for adrenal disease which can be done by almost any vet are melatonin, Lupron, or deslorelin.  Melatonin has anti-gonadotropic effects on the body and can help protect the body from the constant hormone stimulation.  It can be either given daily as a pill approximately 8 hours after sunrise, or as an implant injection that can last 3-4 months.  Lupron and deslorelin both work pretty much the same way.  They cause a negative feedback effect on the pituitary gland, resulting in a decrease of signals to the adrenal gland to release sex hormones.  They have also both been shown to actually slow down the progression of adrenal disease.  Lupron is given as an injection either once monthly, once every 3 months, or once every 6 months depending on which preparation of Lupron is used.  Deslorelin is given as an implant injection and can last up to two years.

A longtime ferret vet, Dr. Robert Wagner, is currently working on an actual adrenal disease vaccination, but it is still several years away from being commercially available. 

Insulinoma.  This is probably the second most common disease we see in ferrets.  Insulinoma is when the pancreas develops multiple little tumors on the insulin producing cells in the pancreas.  These tumors are called insulinomas.  When this happens, these tumors start cranking insulin into your ferret, and your ferret does not have enough circulating glucose to counteract the insulin.  Eventually your ferret's blood sugar starts dropping.  Initially you may see a decrease in energy, drooling, "star-gazing" where your ferret will just stare into space, hind limb weakness like a drunken walk, and as a worst case scenario, hypoglycemic seizures or death.

There are two primary treatments for insulinoma, surgery or medical treatment, much like adrenal disease.  Surgery can be performed to remove up to 60 percent of your ferret's pancreas.  If your ferret is lucky enough to only have a few insulinomas, and they are removed with the surgery, then it is a cure.  However, if the insulinomas are everywhere in the pancreas, which is far more common, then the surgery will just minimize the amount of excess insulin being produced, and potentially lengthen the amount of time that medical treatment will work for your ferret.

Medical treatment involves one primary medication, with two other potential adjunct medications.  The primary medication is prednisolone, which increases the amount of glucose your body produces from the stores in the liver.  This helps to counteract the higher amounts of insulin in the body.  Another medication which does not work well by itself but can help prolong the time that steroids will work is diazoxide.  Diazoxide, also known as Proglycem, reduces the amount of insulin produced from the healthy pancreatic cells, reducing the overall amount of insulin in the body.  A third medication which can help to a small extent is a cat arthritis medication called Cosequin.  This medication contains glucosamine, and while no one can explain exactly how it works, it seems to provide another form of glucose to help counteract the insulin, but without the spike and crash that are associated with straight sugar ingestion.

With medical treatment, your ferret may need higher and higher doses of prednisolone over time.  Eventually your ferret will exhaust all of the glucose stores in the liver, and you will have to make the decision as to whether or not to euthanize your ferret, or to let them die of insulin shock.  Insulinoma pretty much sucks as a ferret disease.  If your ferret develops insulinoma, you may also want to consider purchasing a glucometer calibrated for ferrets to be able to monitor your ferret's glucose levels. 

Lymphoma.  This is the third most common disease in ferrets.  Just like in cats, lymphoma can develop anywhere in the body.  In ferrets the most common organs affected are the spleen and liver, but they kidneys, intestines, spine, pretty much anywhere can be affected by lymphoma.  Lymphoma is a malignant systemic cancer that affects the lymphatic system of the body.  You cannot diagnose lymphoma by blood work.  The only way to definitively diagnose lymphoma is by biopsying affected tissues.  In some cases you can find it in an enlarged lymph node, but more often a full exploratory surgery with biopsies of abdominal organs will be required for a definitive diagnosis.  The good news is that ferrets do respond fairly well to chemotherapy, the bad news is that chemotherapy is still not a cure, it just buys time, and can be fairly expensive.  With most ferrets, if we have a high suspicion or a confirmed diagnosis, and chemotherapy is not an option financially, we will treat with steroids to decrease inflammation and increase appetite for as long as there is a quality of life.  Once the quality of life goes away, euthanasia is far kinder than letting your ferret die of lymphoma.

Cardiomyopathy.  This is probably the fourth most common disease in ferrets, but a little more difficult to diagnose.  Ferrets are prone to both hypertrophic cardiomyopathy, which is a thickening of the ventricular walls, and dilated cardiomyopathy, which is a stretching and thinning of the ventricular walls.  While both can be treated with ace-inhibitors and diuretics, there are more specific heart medications that are more effective, but completely different for the two different heart diseases.  In early stages, an x-ray will not differentiate the two, although in later stages an experienced ferret vet can tell the difference on an x-ray.  The most common symptom you may see with cardiomyopathy in your ferret is a decrease in energy, and if your ferret develops congestive heart failure with fluid backing up into the lungs or chest cavity, then you may also see an increased respiratory rate, effort, or both.  Cardiomyopathy can be managed with medications to prolong your ferret's length and quality of life, but eventually the heart will give out.  As long as your ferret does not develop congestive heart failure however, this is a very painless and low stress disease.

Influenza.  Yes, your ferret can get the flu.  In fact, they can get the same flu you have, and then give it to another person in your family.  Ferrets are the only animal in the world that get the same flu strains as people do.  So, if you or someone in your home has had the flu recently, and your ferret suddenly seems lethargic and doesn't feel good, we will consider the flu as a cause.  Just like in people, the drug Tamiflu can help ferrets, but the sooner they are treated, the more effective it will be.  In later stages, all we can do is supportive care - fluids, hand feeding, etc., to nurse your ferret through it.

Mast cell tumors.  Ferrets are very prone to mast cells tumors on their skin.  These are almost always benign tumors, and other than being a nuisance and itchy, very rarely metastasize.  However because there is a very slight potential of metastasis, and because they do itch, we recommend having these removed once you find them.

Chordomas.  These are benign tumors of the remenant of the notochord (the precursor to the spine and spinal cord in a fetus) in a ferret.  They are most commonly found on the tail, but rarely can develop on other areas of the spinal cord.  If we find them on the tail, we can simply amputate that part of the tail as they will just continue to grow.  However if they develop on other areas of the spine, they can cause an ascending paralysis to your ferret that will necessitate eventually euthanizing your ferret.  They are not surgically treatable, and do not respond well to chemo or radiation therapy.

There are many other diseases that we can find in ferrets, however if you own ferrets long enough, you will probably have a ferret with one of the above listed diseases.  Ferrets are not a miniature dog or cat, they have their own specific medical needs and issues.  If you do not feel that your current vet can adequately diagnose or treat your ferret, we are happy to work with them to get the best care for your ferret.  If you prefer to travel to a more ferret knowledgeable vet, but don't live in south east Nebraska to travel to All Feline, we may be able to give you a recommendation of a closer vet that you can work with.  Probably the most important thing to look for in a ferret vet is a willingness to listen to you, and to do research, learn what they can in ferrets, and know when to ask for help from other vets.