VetInfo Digest February 2000
February is promoted as Dental Care Month in veterinary medicine. So we're going to go with the theme and
devote this issue of the VetInfo Digest to dental care issues. There is probably no area of veterinary medicine in
which the specialists are so far apart in attitude and skill from general practitioners than dentistry. For most general
practitioners, dentistry means cleaning teeth or removing them. Veterinarians do not get more than a few hours of training
in dentistry in veterinary school. This simply isn't enough time to really learn how to care for teeth. Dental specialists
believe that teeth should be saved, whenever possible, and work hard to promote that attitude. It is an uphill battle.
Veterinary clients are often caught in a bind. If they wish to try to save teeth, they may not be able to find anyone
locally who is skilled enough to help them. Cost can be prohibitive for many clients who might otherwise try to save
teeth. I think that dentistry is going to be the growth area in veterinary medicine over the next few years because
there is a need for better care for pet's teeth and people are getting used to the idea that dental care can improve
their pet's life.
This Month:
Dental Definitions
Do you need a veterinary dentist?
What should you do for your pet's teeth?
Disease Profiles:
Feline Odontoclastic Resorption Lesions
Gingivitis/Stomatitis
Facial Fold Pyoderma
What should your vet do for your pet's teeth?
Definitions Associated With Veterinary Dentistry
There are a lot of words used in dentistry that have specific meanings. Often these words sound familiar but are
hard to define with precision. Knowing what they mean can be important, so we are providing the following list of
definitions, just in case it is necessary.
Canine teeth- These are the four large "fangs" that are found in both dogs and cats. Of course, it would also be
correct to call any teeth that belong to a dog "canine teeth", but you get the idea.
Incisor teeth- These are the small teeth at the front of the mouth that are found between the canine teeth. Dogs
and cats usually have six upper and six lower incisor teeth.
Premolars- These are the teeth that are found between the canine teeth and the molars. The largest tooth along
the upper side of the mouth in both dogs and cats is usually the last premolar (fourth premolar).
Molars- These are the teeth at the rear of the oral cavity. The largest tooth along the lower jaw in dogs and cats is
usually the first molar.
Carnassial Teeth- Together, the upper fourth premolar and the lower first molar are referred to as the carnassial
teeth. This is where the crushing power in a dog's or cat's bite occurs.
Dental plaque - This is a coating made of up of glycoprotein and bacteria that covers teeth quickly if it is not
mechanically removed in some manner, such as brushing. It is soft and easily removed.
Dental calculus- This is the hard material that forms on teeth when plaque is allowed to stay on the teeth too long.
It usually has to be removed by scaling the teeth.
Gingivitis- This is the stage of gum disease in which the formation of calculus has reached the point that it is
irritating the gums and causing inflammation, but not enough to cause bone loss around the tooth, in the dog. In
cats, gingivitis is often a disease all by itself. Cats develop several forms of gingivitis, which can be quite severe, that
do not necessarily require the formation of calculus on the teeth.
Periodontitis- This is loss of bone around the tooth and will eventually lead to loss of the tooth itself. In most cases
there is gingivitis and obvious loss of the soft tissue attachments to the tooth, as well. In some cases, there is bone
loss without much gingival inflammation visible so there isn't always a clear progression from dental plaque to
dental calculus to gingivitis to periodontal disease, even though most commonly that progression is seen. When a
pet has periodontal disease, the loss of a tooth, or teeth, is imminent. In many cases, the loss of the tooth can not
be prevented when periodontitis is already well established.
Deciduous teeth- Just like in humans, both dogs and cats have a set of "baby" teeth that fall out and are replaced
by permanent teeth. These teeth are known as deciduous teeth.
Mandible - This is the lower jaw
Maxilla- This is the upper jaw
Endodontic - This is the name for procedures in which the inside of the tooth is treated. Root canals, repair of
fractured teeth, fillings for cavities (caries) and similar procedures are all endodontic procedures.
Orthodontic- When teeth have to be realigned to correct bite problems, this is an orthodontic procedure.
Sometimes this term is also used to describe specialized braces applied to help fractured jaws heal.
Exodontic- This is my favorite dental word. It means to remove the tooth or teeth. "We did an exodontic
procedure," sounds a lot more professional than "We pulled a tooth," doesn't it?
Scaling- This is removal of calculus (tartar) formation. Usually this is done using some sort of instrument made for
the purpose. Hand scaling usually refers to using hand held instruments like the scrapers we all hate the sound of.
Ultrasonic scaling is the use of instruments whose movement is caused by high frequency sound to break up
calculus. Either method is acceptable if done well. There are some other power driven (air driven) instruments for
scaling.
Do you need a veterinary dentist?
There are veterinary dental specialists (veterinary dentists). Currently, fifty veterinarians spread across the United
States, Canada and Australia are certified by the American Veterinary Dental College. Most veterinarians do a
lot of dentistry work in their practices but the work tends to center around teeth cleaning, oral tumor removal and
extractions of teeth. Whether a vet offers more advanced services like endodontics varies depending on the vet's
interest in dental procedures, available equipment and experience with dental disorders. If your vet is very
interested in veterinary dentistry and has invested in specialized dental equipment there may be no need to go to
a veterinary dentist at all.
I think that most veterinary dentists would say that a veterinary practice is not really equipped to do more than
basic dentistry tasks unless the veterinary practice has invested in dental equipment, such as air driven drills, dental
scalars and equipment like this that you are accustomed to seeing in your own dentist's office. I'm sure that your vet
would be willing to show you the equipment available in the practice for dentistry, if asked. A practice's regular
X-ray machine will work for taking dental films but is cumbersome to use for this purpose. Most practices where
dental work is emphasized go ahead and purchase a specialized dental X-ray unit. It is at least a good sign that the
practice is serious about dentistry.
We refer patients whose owners wish to try to save damaged teeth, that need orthodontic procedures and
sometimes for severe gingivitis disorders. We remove most of the teeth that need to be extracted and do routine
dental prophylactic procedures in the practice. We take some X-rays of dental problems using our standard X-ray
machine. This is a good compromise for a rural area but may not be as acceptable in more urban environments. If
there is a veterinary dentist in your area, it makes sense to use their services if your vet suggests it. You can also
request a referral for difficult cases of gingivitis in cats, periodontal disease in dogs, endodontic, orthodontic or
even difficult exodontic procedures. For just plain pulling of teeth, a regular vet will almost always do, though.
Unless your vet is like my wife, who usually disappears whenever the first mention is made of removing teeth.
Just remember that you have the option to ask for referral to a veterinary dental specialist, at least in many urban
areas.
What should you do at home ?
You should look in your dog or cat's mouth fairly frequently. If you know what the inside of your pet's mouth
usually looks like, you will be able to recognize when a problem is occurring.
It is usually pretty easy to roll the lips back and look at the sides of the teeth. This is helpful in determining if there
is dental calculus accumulating on the teeth. It helps identify broken teeth. Look carefully at the large premolars
in dogs. These teeth often fracture in such a way that the outside enamel of the tooth is broken off but the tooth
almost looks normal. It is easy to miss this problem if you don't look at the teeth enough to know what normal teeth
look like.
Open your cat's or dog's mouth, if possible, and look at the tongue and palate. There is a small bump on the roof
of the mouth of most dogs. It is on the mid line of the palate just a little bit behind the front row of teeth. It is called
the incisive papilla. Once or twice a year a client in the practice will notice this for the first time and bring their dog
in for us to examine because they think she has an oral tumor.
If your pet develops bad breath (worse than the usual "dog breath" or "cat breath"), have your pet examined by
your vet. We find that many times odors that owners assume to be from the oral cavity are actually from the facial
folds and it will make your pet much more comfortable to resolve the infection there. In addition, oral odors may
occur from infected teeth, excessive dental calculus formation, foreign objects caught in the mouth and even
conditions like tonsillitis.
Many dogs and some cats will allow their owners to brush their teeth. If you don't mind taking the time to do this
and if your dog or cat is cooperative, you can improve your pet's chances of retaining its teeth and health a great
deal by brushing teeth. As in people, twice a day brushing would be ideal. Brushing at intervals longer than every
48 hours is of questionable value over the long term. It helps to start by using a finger to rub along the gum line,
then using a finger toothbrush or soft cloth over the finger and finally using a toothbrush made for pets. Veterinary
dentists routinely advise against using human toothpaste, but many of my clients come in who are already using
human toothpaste to brush their pet's teeth, with no apparent problems. I tend to think that it may be true that
toothpaste made for pets is better for them but only slightly. Do most vets brush their pet's teeth regularly? I doubt
it. However, I do think that most vets are pretty good about making sure their pets have regular dental prophylactic
care.
There are diets made to control dental plaque and dental calculus. Hill's t/d diet is pretty good for this. I have used
it in my pets with good success. My dog who needs it most doesn't like the food very much, though. I am not
overly impressed with the tartar control cat food, so far. That opinion is based on observance of my patients and I
don't know for sure if it is being fed as the sole food. I don't see much benefit at all to the tartar control treats that
are available for cats. Milk Bones (tm) are only marginally effective for tartar control. Rawhide chew treats are
better, especially the ones that are flat rectangle pieces, such as Chew-Eze (tm). Real bones help a great deal with
control of dental plaque and calculus but they sometimes break teeth, especially the carnassial teeth. The same is
true for Nylabones (tm). It is hard for me to decide whether it is better to go for the teeth cleaning effects of bones
and Nylabone type toys or to avoid them to keep teeth from breaking. So I tell clients to do what they think is best
given the benefits and risks.
The fact that anesthesia is required for good dental cleaning in most dogs and cats causes many pet owners to
put off necessary dental care. The cost of dental prophylaxis in veterinary medicine is increased by the need to
use anesthesia and this also makes many veterinary clients think twice about these procedures. There is a small risk
associated with anesthesia. It is less for dental procedures than for surgical procedures because patients do not
have to be kept in deeper planes of anesthesia to accomplish most dental procedures. The increase in comfort and
health associated with proper dental care outweighs the risk of anesthesia by a big margin. Many more pets will
experience an increase in quality of life and in length of life than will have any sort of complication from anesthesia.
The difference in some of my patient's attitudes before and after dental care is absolutely astounding. Be careful
with anesthesia. Let your vet run a pre-anesthetic blood panel to help plan a safe anesthetic procedure. Isoflurane
and sevoflurane are very safe anesthetic gases and are especially useful for short, minimally painful procedures
when they can often be used as the sole anesthetic agent. This is one of the really frustrating issues in veterinary
medicine. While we can not take the risk away entirely, most veterinarians would agree that good dental care is so
beneficial that it justifies the risk of anesthesia. I anesthetize my geriatric, diabetic, congestive heart failure affected
dog three or four times a year to clean his teeth. I know it is worth the risk, even in his case.
Disease Profiles
Odontoclastic Resorption Lesions
This is a disorder of the teeth that occurs in cats. It is also sometimes referred to as cervical neck lesions, feline
dental resorption lesions or cervical line lesions. In this disorder, the enamel of the tooth is resorbed, apparently
by a group of cells called odontoclasts. Normally these are the cells responsible for causing the resorption of
deciduous teeth so that they fall out. They exist in adult teeth but are not normally active. These cells resorb the
enamel at the level of the gum line, producing a hole in the tooth similar to a cavity. Eventually, enough of the tooth
is resorbed that it falls out or breaks off, leaving the root in place. This is a very common problem in cats.
Somewhere between one-fourth and two-thirds of cats have had at least one odontoclastic resorption lesion in
studies of this condition. (Veterinary Clinics of North America, Feline Dentistry, Nov 1992). If there is an
underlying cause for this condition it has not been identified at the present time.
Cats with resorptive lesions usually have inflammation of the gums over the affected area. Often, there is growth
of gum tissue that extends over the lesion, producing a visible alteration in the gum line. If one of these lesions is
stimulated by touching it with a dental probe or applying cold water to the lesion the cat will usually show signs
of pain. Cats affected with these lesions will sometimes chatter their teeth or paw at their mouth, both signs
normally associated with pain originating in the teeth or oral cavity. The presumption among veterinary dentists
is that these lesions are uniformly painful once they are advanced enough to produce a hole in the enamel. Their
recommendation is to remove affected teeth to alleviate the pain, since there is no effective long term treatment for
this condition. In a few cases, the tooth appears to be critical to the cat. There are treatments which can help to
lengthen the time before these teeth have to be removed but in the long run, removal is still usually necessary.
With a prevalence rate of twenty-five percent or more, it seems as if general practitioner veterinarians should be
extracting many more teeth from cats than they are. I can not speak for all practitioners, but I remove teeth due
to this condition once or twice a month. I see cats affected by this condition every week. Most of these cats are
not showing visible signs of pain. They do have signs of inflammation around affected teeth and they do react if
these teeth are examined with a dental explorer. I tend to think that the veterinary dentists are correct and that I
should be removing more of these teeth. However, removal of teeth with odontoclastic lesions is actually harder
to accomplish successfully than removal of normal teeth and much harder than removing teeth affected by
periodontal disease. It is necessary to use general anesthesia to remove the teeth. It is important to get the entire
root because leaving part of it may allow the inflammatory process to continue and may not alleviate the pain
associated with this problem. This makes the removal of these teeth relatively costly. Cats with this problem
tend to develop it in other teeth as time goes on.
Most owners can not discern that their cat is in pain from these lesions. It is hard to convince people to spend
two hundred dollars to fix a problem they can't tell exists while also taking some risk of problems due to general
anesthesia. Add to this the strong possibility that the whole procedure will have to be repeated in a few months to
a year or two and it is difficult to get people enthused about removing these teeth. So despite the fact that I tend
to agree that cats with this problem probably are in pain, I am not highly successful in getting cat owners to allow
me to remove teeth when odontoclastic lesions are the only problem. When I am able to convince pet owners that
the teeth are painful and when we succeed in removing all of the root structure, I really do believe that cats are
more comfortable. It is worth considering this option for a cat with this problem, especially if your cat does show
signs of oral pain. Vigorous attention to keeping the teeth clean and use of antibacterial products such as
chlorhexidine gels or liquids may prevent formation of these lesions or at least slow the progress of the disorder.
Chronic Inflammatory Gingivitis (Gingivostomatitis) in Cats
Chronic inflammatory gingivitis that is not directly related to the usual progression of dental plaque, dental calculus,
gingivitis and then periodontal disease, in cats, has been referred to as gingivitis/stomatitis, plasmacytic/lymphocytic
gingivitis, plasma cell gingivitis, plasmacytic stomatitis and probably a number of other names, as well. There are
some variations in these conditions but they are similar enough to consider together as a disease syndrome.
Cats can develop very severe gingival inflammation without having dental calculus formation. This condition can
lead to obvious oral pain, severe inflammation of the oral tissues, bad oral odor, loss of appetite and lethargy. This
condition can occur early in life (less than a year of age) in some cats, but usually shows up in young adult cats. The
presence of dental calculus seems to accelerate the onset of this problem and can independently cause gingivitis,
so it is important to clean the teeth and keep them clean while attempting to treat chronic gingival inflammation in
cats. This is the basic step in treatment and it is sufficient in many cases to control gingivitis without further treatment.
When keeping the teeth clean on a regular basis doesn't work, treatment for gingivostomatitis in cats can be
frustrating. There are several medications that are used for this condition and none of them works effectively in all
cases. In some cats, the use of antibiotic therapy, usually using clindamycin (Antirobe Rx) for 5 days of each month
will control the gingivitis. This can be supplemented with chlorhexidine rinse or gel products such as CHX (tm) if
necessary. Omega 3 fatty acids are also helpful in combating the inflammation associated with chronic gingivitis in
cats. There are a number of omega-3 fatty acid sources available. These are safe products to use, so they should be
considered for all cats with this condition.
Corticosteroids, such as prednisone or methylprednisilone injections, work well to control plasmacytic/lymphocytic
gingivitis in most cats. For this reason, they are the mainstay of treatment for this condition. In some cats topical
corticosteroids, such as Lidex (Rx) gel will work but most cats require oral or injectable corticosteroids.
Bovine lactoferrin will help to control gingivitis in some cats. When this product works it is considered to be safe to
use long term and it works very well. Unfortunately it appears that only about twenty percent of cats respond to
lactoferrin use based on initial case reports. The usual dosage of lactoferrin for cats is 175mg/day. It is either mixed
in milk and swabbed on the gums or given orally mixed with food. I do not know which application method works
better.
Surgical treatment of the inflamed gums with a CO2 laser has been reported to control gingivitis well in many cats.
Lasers are becoming more common in veterinary practices and many of the veterinary referral practices have this
capability now.
Removal of the teeth in the affected area usually will help a great deal to control gingival inflammation. This sounds
like a really bad idea but most cats feel so much better without the gingival inflammation constantly bothering them
that they do not appear to miss their teeth much. It is very important that the entire tooth be removed, so careful
extraction is necessary. If a portion of the root is left behind in cats with chronic gingivostomatitis, there is often a
continued reaction at the site that the root is retained.
As we have pointed out before, when there are a large number of treatments for a condition it usually means that
none of them work all the time. This is certainly the case for chronic gingival inflammatory conditions in cats but
usually it is possible to find a therapy that will work, if you and your vet are persistent enough.
Plasmacytic/Lymphocytic Gingivitis in Dogs
Chronic gingival inflammation in dogs is a little different than cats. For the most part, dogs develop gingival
inflammation as a direct result of dental plaque leading to dental calculus leading to gingivitis and then periodontal
disease. In some dogs, the gingivitis stage seems to be more severe and some dogs do have
lymphocytic/plasmacytic gingivitis that is demonstrable by histopathology. Some dogs appear to develop this
condition due to food allergies or to other allergic conditions, though. These dogs respond to many of the same
treatments as cats. Since side effects of corticosteroids affect dogs more than they do cats, it is particularly
important in dogs to try regular dental prophylaxis and home care of the teeth, such as daily brushing, before
moving on to medical therapies. Antibiotics on a pulse basis, such as the first five days of each month, is also
reported to be effective in dogs for many cases of chronic gingivitis. We have used this therapy and have found
it to be helpful, especially for dogs whose owners really can't brush their teeth. We also like the chlorhexidine
products (CHX rinse and gel) for dogs.
Facial Fold Pyoderma in Dogs
This isn't really a dental disease but it is probably the disease most often mistaken for dental disease in dogs, at
least in our practice. It is particularly common in cocker spaniels, Pekinese and rottweilers in our practice area.
We see this problem in other breeds occasionally, though. The most common problem with facial fold infection is
a deep infection of the lower lip where the upper canine tooth rests when the dog's mouth is closed. These
infections smell really bad sometimes despite being difficult to see. Often, only a very small amount of exudate is
present on the skin and the fold must be spread apart to look for visible inflammation. Pekinese get this same
problem in the deep facial folds between their lips and eyes and it can be very hard to detect in them, as well.
Antibiotic therapy is often effective at resolving these infections. Unfortunately, they have a strong tendency to
recur, though. If this is a persistent problem in a dog, removal of the facial fold is very effective. This is usually not
an objectionable procedure for pet owners whose dogs have infected lip folds but it is usually difficult to convince
a Pekinese owner to allow surgical removal of even a portion of the facial fold. If surgery isn't an option we have
reasonably good success using benzoyl peroxide shampoo or chlorhexidine shampoo or conditioner on a regular
basis. Often it is necessary to treat the folds two to three times a week to control this problem.
What should you have your vet do for your pet for routine dental care?
There are a few important dental procedures that are often overlooked.
Puppies and kittens should be checked for palate defects if there is milk leakage from their nostrils when they
nurse. It is best to check for this on the first puppy or kitten visit, even if no signs of problems have been seen at
home. Especially in puppies, small cleft palate lesions may be present without too much outward evidence of
them. These can be usually be repaired and doing so helps prevent inhalation pneumonia and upper respiratory
infections associated with palate defects. It can be hard to get these to heal, even with surgery, but there are a
couple of new surgical procedures that work well. If your vet isn't comfortable doing surgery for palate defects,
referral to a surgical specialist is a good option.
Another early problem your pet may encounter is retained deciduous teeth. This is most commonly a problem with
the upper canine teeth but can occur with any of the teeth. At about 4 months of age, the deciduous teeth start to
fall out. The incisors usually come out first, followed by the premolars and then the canine and molar teeth, which
usually fall out at about five to six months of age. If the deciduous canine teeth do not fall out they tend to act like
mini-braces, pushing the permanent canine teeth toward the mid line of the mouth. This can cause the permanent
canine tooth to rub against other teeth or even to push into the palate. In order to prevent problems it is best to
remove the deciduous teeth if they are still present when the permanent teeth get more than halfway in. We try hard
to remember to look for retained baby teeth when we do spay and neuter procedures. If you notice retained baby
teeth before you bring your dog or cat to the vet's for spaying or neutering it is best to ask your vet to remove
them, since your pet will be under anesthesia, anyway.
Make sure your vet looks at your pet's teeth and in your pet's oral cavity during yearly physical exams and
preferably at each office visit. Just ask, "Do Fluffy's teeth look OK to you?", if your vet seems to be forgetting.
While many, probably even most, vets would disagree, I think it is possible to do a reasonably good job of dental
calculus removal in most cats during a yearly physical exam, without the use of anesthesia. I can not explain why
cats will allow the removal of calculus more frequently than dogs, except that it is generally easier to remove
calculus from cat teeth. We have been doing this as part of our yearly physical exams for four or five years now. I
truly believe that it is beneficial. It does not eliminate the need to do more in-depth cleaning at times but it does
prolong the interval between dental prophylaxis visits requiring anesthesia. If your cat is a reasonably cooperative
patient, you might ask your vet to consider attempting to hand scale the accumulated calculus on a yearly visit.
Your vet might refuse but at least he or she will know you are interested in your pet's dental health and will
schedule a visit to have the teeth cleaned, if necessary.
If your vet mentions that your pet has tartar or dental calculus accumulation, ask to schedule a dental prophylactic
visit. It is easy for your vet to forget to do this if something else distracts them later in an exam .
Odontoclastic resorption lesions are often overlooked in cats. It is necessary to keep a high degree of suspicion for
these lesions.
We think that there is a correlation between unexplained weight loss and dental disease, based on our patients. This
seems to be especially true in older dogs and cats. While there are a number of causes of weight loss in these age ranges,
it is still important to consider dental disease or other oral diseases when weight loss is a problem and can't easily be explained
by other health problems.
In cats, eosinophilic granulomas affecting the oral cavity are easy to mistake for oral cancer. It is important not to
make this mistake, as eosinophilic granulomas are usually treatable. Biopsy will usually distinguish cancers from
eosinophilic granulomas but an alternative diagnostic approach is treat for the eosinophilic granuloma and recheck
the patient in a week. If there is a response to treatment, especially a complete response, then biopsy may not be
necessary. Also, we find that enough cats with eosinophilic granulomas on other parts of their body also have oral
lesions that it is worth checking for them in any cat affected by this condition.
The VetInfo Digest is published by:
TierCom, Inc.
P.O. Box 476
Cobbs Creek, VA 23035.
The opinions expressed in this newsletter are those of Michael Richards, DVM., author.
Copyright 2000, TierCom, Inc.