In my own research, I have found the probability of a New Zealand feral
ferret having one or more damaged teeth to be 0.08.  That means about
eight ferrets out of a hundred (all age classes combined) have one or
more broken teeth.  Ready for the really interesting part?  I have found
pet ferrets (all age classes combined), most having never touched a bone,
have a probability of 0.68 they will have one or more damaged teeth.
Ferrets eating bone SHOULD have a probability that they will damage one
or more teeth somewhere between 0.08 (NZ feral ferrets) and 0.25
(averaged carnivore), but not exceeding 0.40 (hyenas), yet the
probability of tooth damage within the pet ferret population, 0.68,
greatly exceeds those numbers.  I'll bet most of you could confirm this
number.  Randomly pick out ten ferrets of various ages, and about 6 or 7
of them will have either be missing a tooth, or have one that is cracked,
broken, chipped, extremely worn, pitted, dead, or otherwise injured.
Some people will have a few more, some less, but that is to be expected.
 
This is an EXTREMELY significant finding.  What it means is the
probability that your ferret will damage one or more teeth during it's
lifetime, just doing the things pet ferrets do, is FAR GREATER than if
it was living wild and eating bone-filled animal bodies.  Many factors
can be held responsible for this tremendous increase in risk, including
biting or tugging on cages, nutrition, age of neutering, chewing on
inappropriate objects, falls, fighting, starchy diet, accidental trauma,
and aging.  Tooth damage is accumulative; that is, each injury will
weaken a tooth until it finally fails.  Once broken, teeth cannot be
repaired, so a tooth cracked in a fall remains damaged for the life of
the ferret.  Second, because tooth damage is accumulative, the immediate
cause of injury may not be responsible for the fracture.  In other words,
the tooth may have broken when the ferret ate bone, but it was years of
tugging at the cage door that caused the cracks that led to the fracture.
Because tooth damage is accumulative, fracture rates are heavily
correlated to age.  That is, the older the ferret, the more likely you
will find a broken tooth.  Keep in mind it is not aging that breaks
teeth, but years of accumulative damage.  The two are so highly
correlated that one can be use to predict the other, but one doesn't
actually cause the other.
 
The risk of a ferret breaking a tooth on a bone, while real, is
insignificant.  Like adding a glass of water to a full bathtub, adding
the risks of breaking a tooth while eating bone to the risks of breaking
a tooth just being a ferret, makes little or no real difference.  More
important, there is a real and significant danger in the improper use of
studies to bolster personal opinion, as well as the use of pointing out
academic degrees to bolster trust in that opinion.  These two techniques
are more-or-less valueless in reviewed academic journals, but in a public
forum they can be an extremely potent way to influence people without
resorting to the rules of evidence.  For example, in the refutation by
Bellows, the reference to data in a paper yet-to-be-published (probably
a paper presented at a conference -- rarely peer reviewed), is supported
by reference to her credentials (I'm a DVM and I say....).  Remember the
MEE Whammy?  The myth (bone hurts carnivore teeth) is supported by a
reference to an expert (DVM credentials, person's unpublished study), and
emotion (bones will hurt your pet).  NO data is revealed, the material
has not been peer reviewed, and opinion is disguised as fact.
 
The problem with citing the opinions of credentialed experts as absolute
evidence is that in ANY given field, or ANY given subject, you can find
an "expert" to support your own side.  For every animal nutritionist that
says "unrestricted access to high quality kibble is the best diet for
your ferret," I can find one that says "unrestricted access to kibble
shortens ferret lives, and kibble promotes dental problems, obesity,
gastrointestinal problems, insulinoma, and other debilitating diseases."
People spend so much time worrying about credentials that data is
ignored, or the argument is not critically reviewed.  Frequent reference
to credentials ignores three VERY important things: 1) you don't have
to have credentials in a given field to recognize a scientific con job,
2) you don't have to have credentials to be able to read, learn, and
understand a problem, and 3) having credentials does NOT make you an
expert on ANY particular subject.  There is an old saying, "While you
generally have to be a scientist in a field to generate dependable data,
you DON'T have to be a scientist at all to be able to recognize the data
as crap."
 
Bob C
[Posted in FML issue 4160]