Forgive me if this has been discussed at great length already; I searched
and couldn't find a specific answer to this question.
 
I've owned a total of six ferrets over the past ten years or so.  Of
those six, four have passed away.  Three of those passings were due to
medical issues -- most notably cancerous tumors of some sort, typically
insulinoma.  One of my remaining two ferrets has a serious heart
condition that necessitated the installation of a pacemaker.  All but
one of my ferrets (Sprinkles, who died just two weeks ago) were pet shop
ferrets; Sprinkles was adopted through a private breeder/shelter.
 
My mother has owned five ferrets over a similar time span.  Four are
alive today, and one of those (Snowy) has a strange and
as-yet-undentified form of insulinoma which causes her abdomen to swell
with fluid to a point that every two weeks or so she needs to go to
the vet for an abdominal tap to drain the fluid out.  She is also on
medication twice a day and must be hand-fed; if she misses medication or
feeding, she will go into insulin shock very quickly.  The ferret who
died also fell victim to insulinoma.
 
Also over the years we've owned a wide variety of pets -- dogs, cats,
fish, assorted rodents, etc.  NONE of them have had anything like this
happen to them.  It's now a given that whenever we get a new ferret, we
expect there to be a several thousand dollar medical expense sometime in
their future, typically a surgical procedure of some sort.  But not for
the dogs, cats, etc.  We've owned two dogs in total, ever since I was
about four years old.  Both of them lived for 12+ years and never had
anything like this.  We've owned four cats; one lived about 13 years, the
second was unfortunately hit by a car, the third died of feline leukemia,
and the fourth is still alive and going on her 14th year, though she
looks like she's maybe 4-5 years old.
 
Out of eleven ferrets, six of them (55%) have or had serious medical
issues while four of them (36%) have died from those issues.  Out of
four dogs and two cats, for example, we've had only ONE animal die from
a medical condition.  That's a 16% mortality rate, and I'd bet large
amounts of money that if we had five more dogs/cats that percentage
would drop significantly.
 
So the underlying question to all of this is: Why are ferrets so darned
sickly animals?
[Posted in FML issue 4130]