Make no mistake about it: this type of dental wear is pathological.  The
teeth are not designed to withstand it, it causes or contributes to other
dental disease, and it probably causes enough pain or discomfort to
reduce a ferret s quality of life.  Think about it for a moment.  If you
have a worn tooth, you know how sensitive it can be to pressure; bite
something hard and it hurts like the blazes.  Ferret teeth look different
from human teeth, but the basic design is the same: a pulp cavity
containing a nerve and blood vessels, surrounded by dentine and covered
with enamel.  Imagine how it would feel to a ferret with worn carnassials
trying to chew hard kibble: each bite could potentially cause discomfort,
even pain, leading to mild anorexia and weight loss.
 
You should note the rate of wear is not a linear relationship to time;
it is a curve.  The reason is because enamel is harder than dentine and
when the outer enamel shell wears away, the wear rate increases: the less
enamel, the faster the rate of wear.  This is the main problem with using
tooth wear to estimate the age of ferrets; ferrets with worn teeth are
generally estimated to be older than they actually are.  This is also why
you cannot use dental wear rates determined from wild populations to
estimate the age of pets; the wear rates are not correlated, and because
of diet and other factors, may not be congruent.
 
There is no doubt that the dental wear rates and type of wear is a direct
result of eating a kibbled diet.  The characteristics of wear and
location are as distinctive as a fingerprint.  Of course, diet-mediated
wear is harder to determine in young adults and may be impractical in
juveniles, but distinguishing it in older ferrets is a snap.  It is so
clearly apparent from a forensic point of view that I am convinced the
analysis of wear facets can distinguish a lost pet ferret from one living
in a feral state, and after my European and New Zealand trips, I will
publish such a paper describing exactly how to do it.  Once you know what
to look for, all you would need is an impression of the ferret s teeth
and a few measurements, and you would know without a doubt if the ferret
was a lost or abandoned pet, or if it was truly feral.
 
How can you protect a ferret from the wear caused by a kibbled diet?
You can t; there is not a kibble on the market that doesn t cause tooth
damage.  It is not that kibble was designed to wear down a ferret s
teeth; it was designed to be poured in a bowl and not spoil.  In the
manufacturing process moisture is driven off the food, making the
particles resistant to bacterial growth.  It is made that way because
people want to pour a bowl-full of food and place it on the floor for a
week and never worry about it.  The problem starts when you drive off
the moisture: the resulting product is quite hard, which is why it is so
crunchy.  Because the components of kibble are small, as they harden they
turn into organic sandpaper.  If you feed your ferret kibble, the damage
will be inevitable.
 
The best you can do is to soften the kibble before serving.  One way to
do this is to soak the kibble in water or broth, but generally, this
causes the pellet to disintegrate.  Another method is to place the kibble
in a bowl, spray a light mist over it, then warm it in a microwave; the
water vapor will help to soften the kibble without making it fall apart.
Or, you can simply pour kibble on top of Bob s Chicken Gravy or some
other suitable duck soup.  The kibble should absorb enough liquid to
soften.
 
Cage bite wear is another type of dental attrition found exclusively in
pet ferrets, with 23.8% of the skeletons displaying the trait.  Most of
the wear is limited to the canines and front premolars, which can take
a nasty beating.  As the ferret hooks their canines around the wire and
tugs at the cage, the metal is rubbed against the enamel, sandpapering
it away.  Once the enamel has been breached, the softer dentine wears at
a faster rate, notching the tooth.  When enough of the tooth is abraded,
it is prone to fracturing.  Sometime prior to that point, the tooth
generally becomes sensitive, and the ferret may shirk away from cold or
slightly hot foods.  If the canines are sensitive, even if they are not
used to consume kibble, the discomfort may be enough to reduce their
desire to eat or drink, and they can lose weight, exacerbating other
problems.
 
There is not a lot you can do to stop a ferret from cage biting in an
attempt to escape; I ve tried all kinds of things that rarely work 100%
of the time.  The only thing that I ve found that ALWAYS works is to let
the ferrets free-roam.  However, most people cannot allow their ferrets
to live outside a cage, so some attempt to stop cage biting is in order.
You can extend the time the ferret is out of the cage, but that won t
stop them from cage biting while they are inside it.  One person told me
they recycled a model railroad transformer to run a weak electric current
through the wire; not enough to hurt, but just enough to tickle the
ferret, making cage biting uncomfortable (like the feeling you get when
you lick 9-volt battery terminals).  I think this has potential: perhaps
an electrical engineer can come up with some plans that can safely
perform this task and post them on the FML.  At this point in time,
perhaps the best solution is to buy cages where the screen is 1/2 inch or
less.  This prevents most ferrets from hooking their teeth over the wire.
Using cages with plastic-coated wire might also help reduce the rate of
wear, but I doubt if it will stop it; the plastic quickly wears through
at popular cage-biting locations.  If you have a ferret that refuses to
stop biting the cage, you might want to consider moving it from a wire
cage into wood one with small wire screening, or have a cage built out
of perforated Plexiglas.
 
If you don t stop cage biting, the front premolars and the canines will
take a beating, wear at an accelerated pace, and ultimately fracture.
They become sensitive to touch, and it is possible, although I didn t
see it, that exposed root canals can become infected, spreading disease
to the rest of the body.  Check the back of the canines and the front
premolars regularly, and if you think you have noticed wear or notching,
bring the damage to the attention of your veterinarian.  Most animal
dentists can quickly rebuild the back of the canine with acrylic
material, both restoring it as well as protecting it from further damage.
 
In the next installment, I will discuss missing teeth in ferrets.
 
Bob C
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[Posted in FML issue 4519]