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Pre-Surgical Information
Spaying or neutering your pet is a big step! There is a lot to consider
when we are planning your pet’s surgery. Here is some information to help
you make wise decisions.
Click here . . .
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Special LibraryOur Special Library
is a collection of informative articles on a variety of health topics.
Click here . . .
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Discharge InstructionsClick here for
information on how to care for your pet at home.
Click here . . .
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Dental Disease
Dental disease is THE most common ailment we find in
dogs and cats. Dental disease is both treatable
and preventable when caught early.
Dogs and cats have teeth. Dogs and cats don't
brush their teeth. It should therefore not be
surprising that they frequently develop dental problems.
In order to better understand dental disease, lets start
with a brief review of the pertinent anatomy. I
will use drawings from human dental texts because they
are easier to find. The tooth shapes are different
but all the parts are the same.
Teeth are composed of a really hard outer layer called
enamel. Underneath the enamel is a layer of a
somewhat softer hard material called dentin.
Inside the center of the tooth is the pulp, which is
composed of blood vessels and nerves. A tooth is
alive, and it is the pulp that keeps it alive by
providing blood, oxygen, and nutrition to the living
tissues of the tooth.
The tooth sits in a socket in the bone of the jaw.
It is held in place by its roots. The dentin of
the roots is covered with a layer called cementum, which
helps cement the tooth in place. The periodontal
membrane, or periodontal ligament as it is more properly
called, is a ligament just like any other ligament in
the body. The periodontal ligament is made out of
tough connective tissue, and runs between the bone of
the jaw and the cementum of the roots, and holds the two
together in a strong, flexible, elastic bond. The
gums, or gingiva, cover the bone of the jaw and attatch
to the cementum of the roots leaving a small pocket, or
gingival sulcus, normally less than 2mm deep in dogs,
between the enamel of the crown and the gingiva.
The mouth is an excellent place for bacteria to grow.
It is warm, moist, and there is periodic access to food
for bacteria to grow on. As a result, there are
lots of bacteria present in the mouth. Mostly they
behave and mind their own business. However, there
is the constant temptation for them to get out of
control. This doesn't happen if all the mouth's
defensive mechanisms work right.
Bacteria on the surface of a tooth normally form what is
called plaque. Plaque i s
a biofilm, a thin, translucent film made up of bacteria,
proteins they secrete, and food particles.
Normally, plaque is removed soon after it forms by the
simple act of chewing. Dog and cat teeth
are arranged differently than human teeth in that most
of them do not touch together. That means that
chewing is more likely to be an effective way to remove
plaque than in people. Not surprisingly, we see
the most problems in places where the teeth do touch
together: the incisors in front and between the
big molars in back, and in toy dogs where all the teeth
are jammed tightly in to a small mouth.
If plaque is not removed, the bacteria that form it
continue to multiply. The plaque gets thicker, and
the nature of the bacteria that make it changes to a
more sinister character. The thick persistant plaque will mineralize, forming tartar.
Tartar, although it looks like it might be mineral
deposits, but it is actually about 80% bacteria.
And unlike plaque, tartar is firmly adherent to the
tooth, and neither brushing nor chewing is effective in
removing it.
Problems start to happen when tartar builds up,
especially when it bui lds
up under the gums. In dogs and cats, cavities are
not a real problem. This type of decay seldom
happens in pets' mouths. However, the bacteria in
tartar make toxins and harmful waste products that can
damage the gums and other soft tissues. The
inflammation that results from tartar's interaction with
the soft tissues releases other damaging compounds.
In the images to the right, we see brown tartar building
up both above and below the gum line, and the tissues
are becoming red and swollen because of the
inflammation. As the infection progresses, the
gums and soft tissues are eaten away by the bacteria.
The gingival sulcus becomes abnormally deep, and is now
called a periodontal pocket. The difference
between a gingival sulcus and a periodontal pocket is
that in a gingival sulcus (normal), the root is not
exposed. In a periodontal pocket (abnormal),
the root is exposed. As the periodontal pocket deepens,
soon even the bone itself begins to be resorbed.
Then the infection invades the periodontal ligament and
destroys it,and the tooth becomes loose.
The progression of periodontal disease is often divided
into stages. Although the stages are somewhat
artificial, it is nonetheless very useful to classify it
this way.
Stage One: Mild Gingivitis. Plaque is
present, but tartar is minimal. 
The gums are mildly inflammed, as evidenced by a slight
reddening of the margin, and they are swollen.
There is no soft tissue loss, no abnormally-deep
pockets, and no bone loss. The damage done at
stage one is reversible, meaning we can make it return
to the original, undiseased state with treatment.
Stage Two: Mild Periodontal Disease.
Here there is more advanced tartar build-up with the
accompanying
 inflammation,
but there is beginning to be soft tissue loss, gum
recession, abnormally-deep periodontal pocket formation.
There will be early bone loss too, but less than 25%.
The teeth are not loose at this point. To the
right is an image of a dog's molar with stage two
periodontal disease, and an x-ray of the same tooth.
Notice the bone loss lurking under the gums! The
damage that happens in stage stage 2 periodontal disease
in not reversible! Although we can often achieve
soft tissue regeneration, bone loss is especially hard
to deal with, and we may not ever be able to get the
bone to regenerate. The deep periodontal pockets
that form pose a particular problem in that they are
"tartar traps." Plaque will form in the pockets,
and it can be difficult to remove it by chewing or
brushing, and this makes it difficult to stop the
progression of the disease.
Stage Three: Periodontal Disease.
Here there is severe tartar build-up, advanced soft
tissue loss, dee p
peri odontal
pockets, and considerable bone loss somewhere between
25% and 50%. The teeth, especially the
single-rooted teeth, begin to be noticably loose.
Under these ravaged gums significant bone loss has
occurred. Note particularly the "hole" that has
appeared between the roots of this tooth. Once
this occurs, it is often best to remove the tooth
because plaque and tartar will build up in that hole
almost immediately after it is cleaned.
Stage Four: End-Stage Periodontal Disease.
  This
is as bad as periodontal disease gets. The tooth
has lost over 50% of it's bony support, and is very
loose. The infection has eaten the jaw away from
the tooth. Nothing can save this tooth, and the
patient will be much better off without it. It is
loose, wobbly, and stinky. Needless to say, this
damage is not reversible.
It is important to remember that any one individual can
have some teeth that are perfectly normal, some teeth
that are Grade One, some teeth that are Grade Two, some
teeth that are Grade Three, and some teeth that are
Grade Four, all in the same mouth. It is also
important to remember that we can not grade a given
tooth accurately unless we both probe and x-ray it.
This means that when we examine a patient awake, we are
only guessing at what dental problems may be there.
I hope you have enjoyed this discussion of dental
disease. Click
here for a discussion on when to have your pet's
teeth cleaned, and click
here to go to an article on how to brush your pet's
teeth. |
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