First off, I think it is important to remember that dogs and cats are
generally longer-lived animals.  The average life-span for them is far
longer than ferrets, AND takes into account, because of years of
experience, cancer and other serious illnesses.  The "Average" ferret
lifespan commonly quoted to potential buyers usually does NOT include
stats on cancers, etc.  So it seems ferrets live much shorter lives
comparatively.  But if you talk to almost any pure breed dog owner,
they'll tell you, most of them will have a serious illness within their
lifetimes.  It isn't always a fatal disease.  With some large breeds,
it is a debilitating and painful bone disease or some other such thing.
 
Having had two scottish terriers, I can tell you, one lived to about 14,
which seems to fit into her "average" life span, and yet, she died as a
result of lung cancer, and also had bladder cancer for the last year of
her life.  And our other scottie is only 6, and has suffered from
pancreatitis since she was around 3.  My neighbors dearly departed Chow
wsa 16 when he died.  But he had cancer, too.
 
Obviously, if we look at pure bred dogs as examples, breeding can cause a
propensity toward certain diseases.  A large percentage of scotties will
get bladder cancer.  Labs often suffer from hip displacia.  The list goes
on.  You can even see this type of thing in humans.  If you have breast
cancer in your family history, you are more likely to get breast cancer.
I'm not sure I have a clear understanding of why cancers would have this
hereditary component, but then again, there isn't really a clear
understanding of cancer yet.
 
In any case, I think it is pretty safe to assume that breeding practices
are at least in part responsible for this type of problem.
 
However, I'm not sure any legitimate statistical analysis would tell
you that ferrets are more prone to disease than other animals.  As seen
above, dogs are plenty prone.  Feline lukemia was mentioned in the post.
You've had fewer cats than ferrets, and you have no idea whether your cat
who was hit by a car would or would not have eventually gotten a similar
disease.  The proportions aren't far off anyway.  And every rat I've ever
known has died of cancer eventually.  (Rats just do that.)
 
Its just a matter of having a more realistic average lifespan, I think.
Add to that the fact that most people will have a LOT more ferrets in
their lifetimes than they will either dogs or cats, and more at a time
too.  So you might have 8 ferrets, 5 of whom are sick, and only one
dog, who is healthy for 10 years.  That seems disproportionate, when
in reality it probably isn't.
 
[LY]
[Posted in FML issue 4131]