Slight correction to begin with.  I wrote BBF several times in my last post.
Some people thought it was a typo, and I meant BFF for blackfooted ferret.
Actually, it stands for the extremely rare "Black Booted Ferret" which can
be distinquished by the stainless steel rings that pierce several parts of
it's anatomy, and the slick black leather it wears.
 
Ok, it was just a goof.
 
Actually, I spent most of the day I wrote the post deep in the bowels of a
cave, looking at a deep pile of bones that had been found by some idiot
cavers.  Question were they human or other.  So the bone guy (me) was called
out for an expert opinion (well, at least I have the opinions...).  So I
wetsuited up, harnessed up and roped down about 6 miles.  Ok, about 100
feet, give or take an inch or so.  Good thing I love this type of adventure.
Anyway, on top of the pile (natural accumulation) was male and female skunk
skulls.  Lying side by side.  Well, I was so impressed that when I wrote the
post, I accidently wrote BBF for "Bob's Bone Fantasy."
 
Ok, ok, it was just a goof.
 
Q: Why do older ferrets teeth look different than younger ferrets teeth?
 
A: This isn't one of those "My fang is bigger than yours" questions, is it?
 
The question isn't really clear, so I will guess.  As any animal, including
humans, gets older several things happen to the teeth.  First, they
naturally wear down.  I have seen teeth worn to nubs, basically roots capped
with a thing layer of dentine, especially in domestic animals and wild
ungulates.  Second, the gumline recedes, exposing more of the lower tooth
and root.  You might have heard, "Getting long in the tooth" as an
expression for old age; it refers to teeth looking longer as more root is
exposed by the receeding gumline.  Third, the pulp cavity and roots fill up
with dentine, which changes the light transmission through the tooth, making
it appear darker or transparent, depending on the exact species and tooth.
This is a protection mechanism for the animal, to help in tooth wear,
fractures, and decay.  (The teeth I've seen that have worn through the
enamel into the dentine do not normally have exposed pulp cavities nor root
canals.  You can see where they were however--they've just filled up with
dentine).  These are the major and more obvious changes that take place
through time.
 
In addition to these natural changes, decay and fracture can make the teeth
look different.  Many chemicals stain the teeth; mine are stained by
tetracycline (I'm allergic to pennicillin).  Nutritional problems can cause
discoloration, pitting and banding, and even malformation of teeth.  Genetic
problems can make teeth look weird (I have a coyote skull in which the roots
of the teeth are only about 1/4 inch long or shorter.  Very strange), as
well as disease (I also have several skull of canids that suffered from
rubber jaw syndrome).
 
Finally, some teeth are just naturally different than other teeth from the
same species.  Its called "variation," the genius of evolution.  They can be
longer, yellower, darker, have thicker enamel, seem more transparent, or
even flatter than the same tooth in other individuals.  It is natural for
there to be some variation in tooth morphology.
 
The only other answer would be in reference to permanent Vs baby teeth.
Ferrets have a tooth replacement timetable, just as all other mammals (even
those mammals born with permanent teeth go through a baby-tooth phase prior
to birth).  The canines are lost at about 8 weeks, give or take a week; the
others are usually replaced unnoticed.  The general scheme for most
carnivores is: replace the canines, grow the molars, replace the premolars.
The incisors vary in replacement from species to species, and in most
carnivores, are of little importance and can be lost without much danger to
the animal.
 
Dark teeth usually mean some kind of damage has taken place; it could be a
dead root, cavity or abcess.  I don't believe in waking sleeping bears; if
the tooth is not causing a problem, ignore it.  I have several adopties with
dark teeth; once a week I inspect the tooth and surrounding tissues for
signs of infections/abcesses.
 
I also brush their teeth twice a week; I use a non-fluoride toothpaste with
baking soda, mixed with a few drops of ferrettone.  I don't use fluoride
toothpastes because I haven't figured out a way to get the beasts to spit,
and I have no idea of what a toxic dose of fluoride would be to the little
guys.  Some guys are easier than others, and a couple I can only get the
outside of the teeth.  I use a baby's Oral B, and its covered with hundreds
of tiny bitemarks.  And yes, each ferret has its own toothbrush; marked and
stored in its own box.
 
Mo' Bob and 18 Mo'monkeys (and Angel Gus)
[Posted in FML issue 1714]