Q: "I am really (times infinity) confused about diet and cavities.  Is soft
food worse on teeth?  Does kibble actually keep teeth cleaner?"
 
A: Fishing for answers about cavities?  Ask Caries Fisher, who forces
brushing in personal tartar wars.
 
There is a myth that suggests soft food causes caries (cavities).  This is
simply untrue; I have peered at the teeth of THOUSANDS of animal skulls and
know first-hand that dental caries and periodontal disease are limited in
most wild carnivores.  Since carnivores eat, by definition, "soft food"
(animal flesh), then the scarcity of cavities in that group falsifies the
statement.  Compared to domestic dogs and cats, wild carnivores have VERY
little dental disease.  I am not implying wild animals do not get cavities
or periodontal disease (they so, but it's comparatively limited), but
dental disease tends to plague (or should I say plaque?) domestic species,
such as humans, dogs and cats.  There are a number of reasons for this, but
two important ones are the shift from an evolutionary diet to one composed
of processed foods, and eating fine-ground starchy carbohydrates.  Both
increase dental disease in ferrets.
 
A ferret has highly modified teeth which from the side look like a row of
shark's teeth.  Powered by massive jaw muscles, the two jaws fit together
like pinking shears, easily cutting through muscle, tendon and bone.  The
ferret has a tiny oblong maxillary molar (about 1/16 in by 1/8 in) and a
smaller oval mandibular molar (about 1/16 in), which limits their ability
to chew crunchy foods.  This dentition proves ferrets are extreme
carnivores.  These small molars reflect the inclusion of insects and
crustaceans in the diet, NOT the ferret's inclusion of plant material
(omnivores, like bears, skunks and raccoons, have human-like molars).  The
use of molars to crush exoskeletons is not unusual in mustelids; the sea
otter has MASSIVE molars, yet eats animal food almost exclusively.  River
otters and other mustelids are similar.  Clearly, the ferret's molars are
NOT designed to do heavy work.
 
While a ferret's teeth are exquisitely designed to cut muscle and bone,
they are POORLY designed to chew hard cereal-based foods.  Hard extruded
food flattens the cutting teeth and increases the number of pits and
micro-fractures on the tooth surface.  As the ferret crunches the food,
small particles remain in the mouth, where they dissolve in the salvia
creating a sticky carbohydrate "soup".  This "soup" changes the natural pH
of the mouth, making it a better environment for oral bacteria, as well as
providing them food.  The "soup" sticks to the side of the teeth and reacts
with chemicals in the mouth to form a hard plaque, which irritates and
inflames the gums and can lead to bone infections.  So, not only does the
extruded dry food cause PRIMARY damage to the teeth in terms of tooth wear,
micro-fractures and pitting, it also causes SECONDARY damage to the teeth
by providing a food-filled environment for bacteria, as well as damaging
the gums.
 
Proponents of hard crunchy foods claim the food wears off the plaque,
keeping the teeth clean.  This is true for the surfaces which crunch the
food, but the problem is ferret teeth are blades and have small surface
areas compared to dog's teeth.  This minimizes the ability of the kibble
to scrape off the plaque.  After inspecting the skull of nearly 100 feral
ferrets and comparing them to nearly the same number of pet ferrets, I
noticed little or no plaque or cavities in the teeth of the feral animals,
and a 70% plaque rate and 12% cavity rate in pet ferrets.  Clearly, the
eating of hard grain-based foods does NOT prevent plaque or caries.  So,
why don't feral ferrets have as much plaque or develop as many caries?
They simply do not eat hard grain-based foods; they eat animals.  Eating
animals results in a different oral pH, doesn't create the carbohydrate
rich "soup" in the mouth, nor result in the amounts of dental plaque.
Also, cutting through bone, skin and fur "brushes' the tooth surfaces,
cleaning it of sticky material and bacteria.  Cutting teeth ARE worn down,
and micro-fractures and pits are formed, but at a much slower rate.
 
Take care when buying wet "all meat" diets; they are often swimming in an
ocean of carbohydrate rich gravy, which makes "soup" similar to kibble.
Allowing a ferret to chew softened bones will go a long way to help keep
teeth clean (just boil or pressure cook the bone if you obsess about bone
splinters), but the best way is to limit cereals in the diet.  This is not
possible on a kibble diet, so occasional tooth cleaning is required; ask
your vet for advice.
 
Bob C and 16 Mo' Toothy Tubedogs
[Posted in FML issue 3056]