Beta cell tumors, also known as insulinomas, are the most
common neoplasm in ferrets. These
tumors produce excessive amounts of insulin, causing dangerously low blood glucose levels. Unlike dogs
or cats, insulinomas in ferrets don't usually metastasize. Although the
cause is different, this condition is essentially the opposite of
diabetes mellitus. Diabetes causes insufficient insulin to be produced, resulting
blood glucose levels. Diabetes mellitus is uncommon in ferrets, though not
unheard of, and it can be a transient condition after insulinoma surgery.
Some veterinarians feel that the high incidence of
insulinoma in ferrets may be due to the high carbohydrate diet that ferrets
are fed. Susan Brown, DVM says, “If normal beta cells are bombarded
with higher than normal levels of glucose (which comes from carbohydrates)
they can become hypertrophied (overactive) trying to keep up with insulin
demand. If the high carbohydrate diet continues, the result may be a complete
burnout of the cells, which is what happens when a pet or a person develops
diet-induced diabetes. However, another possibility is that instead of the
cells burning out, they go from hypertrophy to neoplasia (cancer). Neoplasia
is an abnormal growth of cells and can be preceded by a hyperplastic
condition. I would like to stress that this exact mechanism has not been
scientifically proven in ferrets to date, but the scenario is entirely within
the realm of possibility.” (1)
Surgery to remove
visible tumors or a large portion of pancreas frequently does not result in a cure.
Dr. Bruce Williams says, “the incidence of recurrence of insulinoma after
surgery is high, averaging about 40% over a 10 months span.” Even
after undergoing a partial pancreatectomy, some ferrets may not have any relief
from low blood glucose levels. In some cases, with
good care and a combination of medical and surgical treatment, or medical
treatment alone, a ferret may be able to live with this condition for a number of
A normal fasting blood glucose level is in the range of 90-125 mg/dL
(4.95 Mmol/L - 6.88 Mmol/L).
According to Katherine Quesenberry, DVM, in Ferrets, Rabbits and Rodents -
Clinical Medicine and Surgery --- “Ferrets with blood glucose
concentrations lower than 70 mg/dL (3.85 Mmol/L) are suspected of having Insulinoma. In
one study of 49 ferrets with confirmed insulinoma, all had blood glucose
concentrations lower than 60 mg/dL (3.30 Mmol/L).” Ferrets can often have
shockingly low blood glucose levels and have no significant symptoms.
Though I have no medical evidence to back this up, I believe this may be due in
part to the ferret
becoming acclimated to glucose levels that have been decreasing gradually over a
period of time.
The excess levels of insulin produced by these pancreatic tumors drive the glucose in
the blood into the cells of the body, causing a dangerously low blood
glucose level known as hypoglycemia and can result in one or more of
the following symptoms:
- Hypersalivation (drooling)
- a trance or "spaced out" look for seconds at a time
- pawing at the mouth
- Hind leg weakness, wobbly gait
- Head bobbing or twitching
- Dizzy or drunken appearance
- lack of appetite
It's important that a hypoglycemic ferret eats
regular, high protein meals to help avoid hypoglycemic episodes.
Avoid foods with high sugar or carbohydrate (cereal) content. In end
stage insulinoma, sugar may be the only thing that will allow a ferret to
remain seizure free; however, in early stage Insulinoma, sugar may result in a
see saw effect with blood sugar levels.
Treatment for Hypoglycemic Seizures
Contact your vet immediately after beginning this treatment!
Seizures brought on by the sudden drop in blood
sugar levels can be a very frightening experience. Even the
experienced ferret caretaker can feel helpless and in a panic.
For many, the term seizure presents a picture of someone on the floor,
twitching with arms and legs flailing around. This is
usually not what you will see in a ferret that is in the midst of a hypoglycemic
In most cases, ferrets that are in this state
are simply unresponsive and appear to be in a coma like state.
They may have moments of rapid breathing and have repeated
reactions that make them appear to be gasping for air. There
may be some twitching or paddling with their legs. In severe
cases, they may even scream, and though this is very difficult to
hear and witness, rest assured this is not a pain response and the ferret is totally unaware of what is going on.
Treatment consists of quickly getting the ferret's
blood sugar levels back up. The quickest way
to do this is with a dextrose IV. Since this must be given
intravenously, not subcutaneously, this is not something that can
be done at home. Unfortunately, these attacks always
seem to happen when the vet clinic is closed. Besides, in less
severe cases, you can probably bring the ferret around quicker by
starting home treatment immediately rather than racing off to the
clinic unless it is open and right around the corner. Begin
treatment while someone else calls the vet or emergency clinic, or
if you are alone, begin the treatment and while waiting for the
ferret to respond, make the
Home treatment consists of repeatedly painting
the ferrets gums with Karo syrup using a Q-tip. I have found
that Karo syrup works better than honey or Nutrical and thinning
the Karo slightly with a bit of water seems to make it more
readily absorbed. Applying
Karo syrup one time to the ferret's gums and waiting for the
ferret to wake up is usually not going to be very effective.
You must repeatedly apply Karo every 20-30 minutes or so until the
ferret starts to come around. Many say that the ferret will
begin to respond in 5 or 10 minutes, and in some instances,
this is true; however I have not found this to be the case if the
ferret is unconscious.
Many times it has taken an hour or more before the ferret responds.
Once the ferret is alert again, it's important
to feed him or her a high protein meal to help stabilize his or her
blood glucose levels. Chicken baby food works best for this
and anyone with a ferret prone to low blood glucose episodes should
always have some of this on hand, in addition to Karo syrup.
When you are done feeding the ferret, BE SURE to
thoroughly wash off any karo syrup that has gotten on the fur or skin around
the ferret's mouth. If not cleaned off, it can cause intense
itching and the ferret may scratch to the point of bleeding.
RETHINKING THE FERRET DIET - Susan Brown, DVM