Recently, a shelter posted about dealing with insulinoma. I'd like
to comment on that post. Bear in mind, I'm not a vet, just a shelter
operator with 8 years of experience. I probably own -and have read-
every vet text on ferrets in print since 1998 with exception to the
texts on dentistry and radiology. I didn't feel a need to have those
in my personal library. I've also researched extensively on the
Internet to include delightful sites such as Pathology of the Ferret,
Miamiferret, and the FHL among others. Sadly, some information found on
FerretCentral is out of date and needs to be confirmed before following
treatment protocols or soup recipes however, most is still relevant.

Much of what I feel I've learned about insulinoma is based on dealing
with hundreds of ferrets which have experienced this disease. I'm not
an expert, however, not ONE of the ferrets in my care, which had
insulinoma, passed experiencing screaming seizures. I had one with
screaming seizures due to heart and one due to lymphoma of the liver.
Neither had advanced or uncontrolled insulinoma. (My vet attributed
the seizures to the noted organ failures.)

It is becoming more and more convincing that diet is a huge contributor
to the development and rate of advancement of Insulinoma. Yes, I do
feel there can be a genetic element, such as with Neo and others, who
pass at four years of age or younger of uncontrollable insulinoma. I
don't feel they are the norm, though.

We all know ferrets are obligate carnivores. For new owners, this
simply means that ferrets are obligated to acquire their dietary needs
from animal protein. They have little need for, or ability to utilize,
plant proteins or carbohydrates (starches). While there is a lot of
complicated information around different carbohydrates and how they
are digested and used by the body, for the sake of simplicity, let's
just say, carbs are converted to sugars to use in the body.

My personal impression is that Insulinoma is even more widespread,
among the ferret population I've had contact with, than Adrenal
disorders. Still, many ferrets live their entire lives never having
their blood glucose levels checked. A lot of ferrets develop the
disease so slowly, their bodies compensate for the lower blood sugar
levels. While the owner just thinks Bandit is getting older and slowing
down, the fact is, if Bandit had been taken to the vet and had his
blood sugar level checked, they would find Bandit would feel more like
a kit again with a little Prednisilone.

Prednisilone is a powerful drug, even for our rather steroid-resistant
little buddies. It is a med that needs to be respected; however, it is
NOT a medication to be feared or avoided. Blood glucose levels should
always be checked before starting a ferret on pred, AND after, as some
ferrets will not tolerate even a small dose. I've had numerous ferrets
become diabetic on as small as a 0.2 mL dose of 5mg/5mL Prednisilone
when it was given for intestinal issues. Blood glucose levels will
normally stabilize quickly when the pred is discontinued, but not
always.

I have ferrets here, right now, that have been on pred for low blood
sugar issues for over two years. They get small doses that are enough
to bring their glucose levels up to a reasonable level (80's). Blood
glucose levels are checked with a Freestyle meter at home, with my
vet's approval, and adjustments are made and rechecked again within
a week or so. Not one of these ferrets have 'pred belly'. Note: The
readings I get on my glucometer have been compared against my vet's
readings using some of the same sample used by my vet on his equipment.
My meter reads about 10 points below his, on ferrets whose values are
in a 'normal' blood glucose range.

Pred is always given in soft food, which in my home can include
Gerber chicken or turkey, Bob C's chicken gravy or Carnivore Care.
Administering the medication with food will help prevent stomach
irritation. Doing so also hides the taste thus no unhappy ferrets.

My ferrets do have kibble available throughout the day. (Totally
Ferret, Innova Evo Ferret, Natural Gold and some others mixed) If they
get large enough servings of their soft food (about an ounce of chicken
gravy, normally) they will abandon the kibble and still thrive on the
high quality protein in the gravy they get only in the morning and
evening. I suspect it is because the protein in the chicken gravy, baby
food and Carnivore Care is of high enough quality that it is digested
more slowly, reducing the ferrets' urge for frequent feedings and
subsequent blood glucose spikes.

The high carb content of our kibbles, when digested, is converted to
sugar. I was able to stabilize one of my diabetic ferrets, Oscar, using
insulin and feeding Bob's Chicken Gravy exclusively. Once he began to
feel better, and went back to his kibble, his blood sugar level
returned to the 400's by the next reading, requiring adjustment of his
dose of insulin. How can we expect our ferrets, whose systems are not
designed to metabolize the continual glucose surges produced by the
carbs in their kibble, to not have health repercussions? (This is not
an invitation for a food debate!)

This brings me to the issue of supplements. It has been about 8 years
since I have used Ensure or Deliver 2.0 with any ferrets. I just didn't
know better. But as I researched more, and learned about how sugars
affect our ferrets, I abandoned use of them. I will still use Dyne, a
high calorie dietary supplement with rare cases, such as a ferret with
MegaEsophagus, where the key is getting calories in, and worry about
developing insulinoma pales in comparison to keeping the little one
from starving in the next day, week, month. It is my opinion, that
using Deliver 2.0, Ensure or Dyne as an alternative to testing blood
glucose levels versus implementing known and accepted medical or
surgical treatment for the disease is not only unacceptable, but
irresponsible. The ONLY time supplementation with sugars for insulinoma
is acceptable, in my opinion, is during the last stages of the disease
when the glucose level cannot be sufficiently raised by pursuing
surgical intervention provided the health of the ferret supports
surgery, and thereafter, giving maxed doses of Prednisilone and
Diazoxide, if necessary, is no longer sufficient to prevent dangerous
hypoglycemia.

Another supplement that is NOT beneficial for control of insulinoma is
the use of chromium, also known as brewers yeast. While it was once
believed it 'regulated' glucose levels, we now know it only produces
the desired effect if the glucose is elevated, lowering the serum
glucose levels. So, with insulinoma, where the glucose level is already
too low, this supplement is not going to produce the desired result of
raising their blood sugar. Chromium, or brewers years, should only be
used with ferrets suffering from diabetes.

Evidence of Insulinoma is not always obvious, even to a trained and
experienced eye. Several ferrets in my care have demonstrated symptoms
of insulinoma, only to find they have fasting bg levels of 135. Other
illnesses can also mimic symptoms of insulinoma.

Often the ferret's blood glucose level drops so slowly, it's not
apparent to the owner. Some ferrets' systems can adjust to lowered
blood glucose levels without exhibiting many symptoms. Glucose levels
can vary throughout the day.

I have found that stress (such as from visiting the vet) can affect the
reading, artificially elevating the value. If you suspect insulinoma,
but the vet gets an 85, it doesn't necessarily mean the ferret isn't
feeling the affects of the disease. This is why it is beneficial to
learn how to check blood glucose levels at home. One ferret had it's
bg taken at a very ferret savvy vet and his reading was 120, however at
his re-check a week later, the reading was 50 -more in line with what
I was getting consistently at home. Per the Second Edition of Ferrets,
Rabbits and Rodents, the normal fasting blood glucose values for
ferrets is 90-125 mg/dL (Pg 80). Blood glucose concentrations lower
than 60 mg/dL supports a diagnosis of insulinoma.

I feel it's sad to hear a shelter say they don't see the value
of checking blood glucose levels for their ferrets. One of the
responsibilities of a shelter caregiver is to learn how to provide
basic health care for the ferrets in their custody and to work
closely with their shelter vet. It is so simple to learn how to use
a glucometer. Oscar got his bg checked before each insulin injection,
and never once had to have a toenail trimmed short to obtain a sample.
Knowing what the bg level is for each affected ferret is so important.

Insulinoma is a progressive disease. For some, it progresses quickly,
but others, slowly. How can one tell if the dose is excessive or
inadequate without occasional testing? Some ferrets cannot tolerate
even small doses of Pred, so how are you going to detect it, if you
don't re-check?

One shelter operator, after posting they don't see the value of testing
blood sugar asks:

>Does knowing what the glucose level is affect how you are treating the
>insulinoma?

Yes, it does. How can one say their method of giving sugary supplements
and a guess of 0.2 mL dose of pred has been successful when they post
the next day that they just lost their second ferret to screaming
seizures. I really find this disturbing.

I will send a separate post with suggestions for checking blood glucose
levels and another addressing 'Shelter Shock'.

Julie

Julie Fossa 
West Central Ohio Ferret Shelter
http://www.wcofs.org
International Ferret Congress
http://ferretcongress.org/

[Posted in FML 5506]