The Equine Practice Inc

The Trouble With Dentistry As Seen By A Human Doctor

I came across an article on Dr Joseph Mercola’s website.  He is a functional medical physician who is prolific in content helping humans understand their health.  I discovered him when listening to many podcasts as I search for information that will help our horses live better.  This is where the research is being done and the ideas formulated in human nutrition that directly connect to health.  Little if any unbiased research in nutrition in horses regarding their overall health is being done.

The title of his blog is “The Trouble With Dentistry” and clicking this link will open his post in a new tab for you to read.  It may be worth a read just for your own sake, but i saw a direct correlation with what is now prevalent in equine dentistry.  The article covers preventive maintenance and the addressing of dental issues,

Basically Dr Mercola rips apart human dentistry as a profession trying to fix things without proof of the efficacy or the regard to the overall health of the mouth.  From the post:

As noted in recent article in The Atlantic (cited), “[W]hat limited data we have don’t clearly indicate whether it’s better to repair a root-canaled tooth with a crown or a filling.” Derek Richards, director of the Centre for Evidence-Based Dentistry at the University of Dundee, commented on the gaping hole of evidence in the field of dentistry.  “The body of evidence for dentistry is disappointing. Dentists tend to want to treat or intervene. They are more akin to surgeons than they are to physicians. We suffer a little from that. Everybody keeps fiddling with stuff, trying out the newest thing, but they don’t test them properly in a good-quality trial.”

I find a similar situation in the care of teeth and the whole oral cavity in horses.  Just place the word “equine” in front of the word “dentistry” made in the above quote.  The leaders in the veterinary community focus on fixing things they observe with their eyes during the very detailed exam using high intensity lights, mirrors, endoscopy and a well medicated, well immobilized horse.  Rarely do I find comments in their literature that relates what they find to the overall condition of the horse.  

For example, what are the ramifications of administering the medications they use in their routine dentistry?  Texas A&M vet school presented a finding at the AAEP meeting 2 years ago that showed that 1 dose of Previcox (a common pain medication in horses) killed a whole group of the 700 normal bacteria species found every day in the mouth.  Yes there are about 700 families of bacteria that live in the mouth of the horse.  There are trillions of bacteria in, on and around you and your horse.  In layman’s terms, in a neighborhood of about 700 individual families which makes up the thousands living in a town, a whole family was wiped out including aunts, uncles, moms, dads and children.  One dose did that – but with no outward signs of a problem.  The question to ask is what effects occur on the health of the teeth and gums when horses are automatically sedated?  We all know the effect of bute (phenylbutazone) on the lining of the cecum and colon but what about sedation on the oral health of the mouth?  We are all learning of the microbiota of the gut and that any disorganization of this (dysbiosis) leads to ulcer formation in humans.  So what dose the sedative do and is the risk worth the benefit?

Tooth Fractures And Nutrition

In Dr Marcola’s article he cites data that suggest that dental decay starts with nutrition.  

“Excess dietary sugar is the most significant factor driving dental decay. (cited)”  

I find it interesting that when I went to vet school in 1980 there was no mention of tooth fractures in horses.  I cannot believe that this was an oversight.  I have several vet texts from the 1800’s and there is no mention of tooth fractures.  As most of you know by now, if you have been following my blogs, I will probably blame sugar on the cause of this in horses too.  

While fractures can occur in any cheek tooth in the horse, they are most common in the 4th tooth both upper and lower (the 9’s).  I have noticed a swale (a depression or low spot) in the chewing surface of the lower cheek teeth and the outside surface of the upper cheek teeth with the 4th cheek tooth being centered in this swale.  My assumption is that this is the location where the tongue moves across the chewing surface to access the space between the cheek and the teeth.  This movement is constant in positioning food and in cleaning the mouth.  This movement creates premature wear of the surface of the pulp chambers allowing access for bacteria.  Unfortunately the addition of high acid sugars in grains disrupts the normal bacteria in the mouth and like in humans, the opportunistic bad bacteria penetrate the worn pulp chambers.  With time, the decay worsens and impacted food drives further into the tooth creating a wedge that splits the tooth.  

While there is no accurate data here, I can hypothesize that in horses not fed extra sugar there would be no decay and fractures.  I have stated in another blog that the advent of another tooth disease, EOTRH, was not until grain became commonly given to horses.  To quote Dr Mercola again, 

“As Meinig discussed in our interview, the only scientifically-proven way to prevent tooth decay is through nutrition. He related how in Price’s travels he found 14 cultural pockets of natives who had no access to “civilization” and ate no refined foods.  While their diets varied, they all ate whole, unrefined foods. Without access to tooth brushes, floss, fluoridated water or toothpaste, each group were almost all 100% free of caries.”

In Dr Steven R Gundry’s book “The Plant Paradox,” he discusses a 1932 study where oatmeal was linked to the cause of dental caries in children.  Removing the oatmeal from their diets reversed decay in many and prevented further decay in most.

The Health Of The Mouth And The Body Is Connected

Quoting again from Dr Mercola in his article,

“The delicate balance of bacteria in your mouth is as important to your health as your gut microbiome.”

More reasons to go grain free in your horses.  But should you trust the dental findings from the dental expert looking at your horse’s teeth?  As the article says, most people don’t get a second opinion in dentistry like they do in surgery or medicine.  It is a habit we have carried over to our horses.  

With the emergence of several dental conditions not discussed in the veterinary texts before 1980 I can only wonder the contribution of continually feeding sugar (grain, grain byproducts, treats, carrots, apples, etc) has had on the health of the teeth.  Another way of looking at this is to ask how horses managed to survive for millions of years if their teeth decayed and gum disease was common.

It is exciting to open the mouth of the horse and discover disease – at least for the veterinarian.  But after looking at 70,000 horse mouths I am seeing that horses have developed a very robust mouth.  But it doesn’t mean we can abuse the normal bacteria nor can we ignore the delicate balance there between the mouth and the whole horse.  From this perspective I disagree with my colleagues who jump at the opportunity to extract a tooth or do advanced dental procedures.  What is needed is well done routine maintenance without automatic medication removing the daily pain from sharp edges that restrict the movement of the tongue and the distribution of health supporting saliva.  This plus removing the acids of the daily feeding of grain and other sugars will keep the mouth of the horse in great shape for life.

Comments 6

  1. I agree. Sugar is bad but phytic (spelling?) acid is the worst. I have some sugar in my diet and it hasn’t bothered my teeth too much lately but when I chew things like almonds my fillings literally fall out and it’s not due to the hardness of the food. Oats are high in this acid.
    One of my favorite books is called ” it’s all in your head” by doctor Hal Huggins.
    Doc T please also remind everyone not to have they’re older horses ( upper twenties ) teeth floated. I regret calling my new to the business of equine Dentistry young lady who took an Electric Tool to my old but extremely healthy horse’s mouth and filed too much tooth off and since that day has not been able to chew any hay at all. It has cost me a fortune to feed him because of this but he is still going strong at 33.

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      Thanks Bobbie for this comment. It is usually not associated correctly the cause and the effect of things. In reality sugar affects the normal gut bacteria and this in turn has a bad effect on the teeth including causing further decay under a filling. A hard tree nut such as an almond my be all the pressure needed to push the microscopically loose filling away from it’s now poor bond with the tooth.

      As far as advising horse owners to not float the teeth of older horses, I can’t agree. This morning I worked on a 29 year old that needed a few sharp points smoothed and an end stage tooth removed. He then went to immediately eating normally with a purposeful chewing motion, something that had not occurred in months.

      Every older horse I float, especially for the first time, I warn the owners that they may need a few days to learn how to chew again without pain. When this occurs the owner is not surprised. Some young dentists take too much off and this will affect the chewing motion for months to years in older horses. It is the training of these dentists that needs attention and NOT the avoidance of dentistry in older horses. You just had a bad experience and for this I am sorry. I wish all young dentists knew their power inside the mouth of older horses. We teach this explicitly in our dentistry school. Help other people by letting them know that while dentistry helps all horses and especially older horses that have not been floated for a while, they need to verify the credentials of their dentist or at least help them learn about dentistry in very old horses.

  2. Much of this I find to be what we discussed regarding my horse Tara after she presented with a fractured tooth last year and you eventually had to remove part of it. I know you will see her in August, but I want to say that she has not had the rest of her tooth extracted, is eating 2nd cut hay and balanced Timothy cubes as well as flax and mineral mix custom balanced to her hay, salt and vitamin E and has a shiny coat, plenty of energy, a good appetite and is is good body shape (body score around 5). She does not carry any extra body weight and is not thin–just right. Thank you.

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      Thanks Deborah. You had been advised to extract the whole tooth but obviously so far that has not been necessary. Thank you for trusting and doing what was in her best interest. See you in Aug, Doc T

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      There are many theories and beliefs that have developed in equine dentistry since I started in 1983. Some have been good and some have no proof in any evidence (anecdotal or scientific). This includes some from my veterinary colleagues.

      Included myths are equilibration, incisor reduction, balancing the mouth, speculum use, automatic sedation, immobilization, lateral excursion, unnecessary tooth extraction, mapping of the oral cavity and possibly a few more I can’t think of right now. I have written extensively in my blogs ( as well as videoed my thoughts here:

      Thanks for asking about one particular style of dentistry and my apology for answering in a blanket statement, but in the last 20+ years equine dentistry has become divided into entrenched camps. It is much like discussing President Trump. You either are for or against a belief and little argument will persuade a movement away from your belief. I truly am grateful that there are so many people trying to make a difference in the oral health of horses and this includes those who think differently. They are NOT an enemy and all people getting dentistry performed are giving some relief to the chronic oral pain of horses. I just think differently about how to do it.

Your thoughts are important for all to hear and may help others to learn from your experiences. Take the time to add to the discussion. However due to time limitations I will probably not answer direct questions to me. Thanks, Doc T

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