Modern Equine Dentistry for Horse Owners: Understand What You Need to Know to Get the Best Dental Care for Your Horse's Comfort and Safety: Equine Vet Today, #1

AUTHOR PREFACE

Hello and welcome! This preface is designed to give you the keys to best understand this book. Please read it!

For my first fourteen years of equine veterinary practice, I prided myself on my dental abilities—while in truth, I was only providing a Fourth Level dental exam and treatment (you will soon know what that means.). I floated teeth without mirrors, lights, or a full mouth speculum, and often without sedation. I possessed a clunky old museum piece of a speculum—which quite frankly I was terrified to use, especially without sedation—so I only used a unilateral (one-sided) wedge speculum and hand floats. Thanks to my friend and colleague Glenn Beeman, a Canadian New Zealand vet, I saw the light (literally), when he came up from the South Island and placed a proper speculum and light into my horse’s mouth. He showed me what modern dentistry was all about. I was appalled at the pathology I knew I must have missed in my patients’ mouths all those years. It seems I left the USA twelve years before that, those early years when the rapid advancement of modern equine dentistry had truly begun. During this time, I’d been immersed in my new country’s joys of farming and motherhood, plus a few spinal fractures, and somehow missed the revolution.

The once-accepted idea that floating, or removing the sharp enamel points, is all a horse needs for dentistry is long gone. Times have changed and many of us are trying to get the word out to owners who haven’t heard. We now diagnose and treat most of the same conditions your human dentist does. It simply isn’t good enough to perform equine dentistry without carefully examining the mouth, diagnosing dental disease, and treating it before your horse shows outward signs of disease. It’s high time owners were given the opportunity to learn what’s really inside that dark cavern called their horse’s mouth.

Equine dentistry is not a regulated modality in most areas of the world. As such, it is imperative that owners of equids understand what comprises modern equine dentistry. Understanding the principles and limitations of the techniques used to maintain good dentition (teeth) and treat suboptimal dentition allows you, as the owner, to safeguard your horse. By understanding the horse’s oral anatomy, growth, wear patterns, tooth eruption, and diseases, you will be in an excellent position to safeguard your animal's health. Modern equine dentistry can offer your horse the best life has to offer.

A few points about this book:

1- When I say horse, I include all equids, including horses, ponies, donkeys, mules, zebras and the like.

2- You will find I use many medically correct terms but remain calm: I will briefly define some of them in the text, or you will find them in the glossary. Learning more of these words will enable you to understand dental disease more clearly and to more precisely explain your horses’ dental issues to those trying to help you.

3- A survey of my equine practice clients and other horse-keen readers on social media regarding their preference for regular book or question & answer (Q & A) format revealed an interest in both, so for those readers who prefer it, I have included Part Two (Q & A). The items in Part Two refer to relevant chapters in Part One (The Book) for more detail and images. Because those choosing Part Two format will be entering Part One at various points, I have referred to the glossary items the first time they are used in every chapter, rather than once per book, as is the usual. Glossary words will be in italic bold links (in the ebook), or in italic bold (in the print version). So remember, words in bold italic or links are shown in the Glossary.

4- I use the term vet as an abbreviation for a veterinarian who has completed a full course in veterinary medicine at an accredited veterinary school and is licensed to practice in the country (state in the USA, province in CA and other countries) in which he or she is practicing medicine and dentistry. In many places, dentistry is legally limited to veterinarians registered in that state, province, or country.

5- In many countries, a wide variety of people perform equine dental procedures. Some may be veterinarians, some may be well trained and appropriately qualified as an Equine Dental Technician (EDT, see below). Other may be inexperienced people with no or some training (but with no appropriate externally-monitored qualification), who still perform advanced dental procedures. Some of these last unqualified people create injuries, some of them serious or life-threatening, to equid teeth, jaws, and throats.

I reserve the term Equine Dental Technician (EDT) in this book for those who have qualified with a BAEDT (UK) or IGFP (Germany), or an equivalent, though I don’t believe there are others currently operational. The other non-veterinary operators are, for the purposes of this book, termed lay dental operators (lay indicates non-veterinary).

Depending upon where you live, there are different rules for who may perform dentistry. In the UK, for example, non-veterinarians who are not BAEDT-qualified are only allowed to float or rasp small dental overgrowths. Many places (country, state, or province) define equine dentistry as the practice of veterinary medicine. In these places, there may be no regulation or required education of EDTs or lay dental operators. In areas where this is the case, no one other than a veterinarian in that state, province or country is meant to be doing dentistry, unless under veterinary supervision. Several USA states and CA provinces require lay dental operators and EDTs to be registered, but there may be little to no enforcement. In New Zealand, there is currently no non-veterinary regulatory board for equine dentistry, no examination procedure, no continuing education, nor is proof of fitness required of anyone to perform tooth floating or dentistry. This is similar to many places in the USA and many other countries. Because of the lack of uniform rules and regulations regarding who can perform equine dentistry around the world, horse owners should check with their local, state, province, or country regulatory boards to determine the qualifications and legitimacy of individuals offering equine dental services.

6- Technical stuff for the digital edition: With most eReading devices, clicking or double tapping and then spreading fingers apart on an image or graphic enlarges it for ease of viewing. The graphics and images use full-colored images, labels, filled parts, and arrows. If you want to get the most out of this book, it is recommended to use either a full-colored eReader OR download a free Kindle or other colored eReading app onto your iPhone or android phone, tablet, or computer, which will provide you with full color images and graphics.

In the eBook, sub-subheadings appear like this: ". Diastemata and periodontal disease", with three spaces and a dot before the italicized sub-subsection. This is not an error, but to make the Table of Contents work. :)

7- Disclaimers: Reading past this Author Preface is taken as evidence that you understand and acknowledge all concepts in the following subclasses (7a, 7b, and 7c) and fully accept the responsibilities outlined here, in the Disclaimer shown on the Copyright page, and also on the DISCLAIMER page just after the Glossary.

7a- Disclaimer 1: This book has been written with the intent of informing and educating you about the possible dental and other pathologies which may occur in your equids. It is not intended to diagnose disease or pathology, or substitute for the proper diagnosis, treatment, and recommendations of your equine dental veterinarian. It is not a substitute for the consultation or recommendations of your equine dental veterinarian. Call your veterinarian for examination and treatment of your equids.

7b- Disclaimer 2: Regarding you personally attempting to view, touch, or smell any of the anatomical landmarks, teeth, gingiva, skin, and/or any other part of an equid discussed in this book, you are doing this of your own free will. Horses, zebras, donkeys, mules, and any other equids are inherently dangerous creatures. They have teeth to bite with and hooves to kick with. They outweigh us by about ten times. If you get near an equid, you are responsible for your own life and your own safety. No person associated with this book, publishing, images, or information in any way takes any responsibility for any injury to you or anyone else you know if you try to check out anything mentioned in this book. Any injury, loss of income, or loss in any way you sustain is entirely your choice and none of us are responsible nor liable.

7c- Disclaimer 3: This book is not a manual to teach you or anyone else how to perform equine dentistry. The book has been created with solely three intents: 1- to offer you the information which will enable you to understand more about equine dentistry, 2- to enable you to determine and choose the level of dentistry you desire for your horse— for your horse’s and your own benefit, and 3- to enable you to judge, to a greater degree than you might be able to right now, the competency of the person you schedule to perform dental work on your horse. This book is a summation, in layman’s language, of the current information (as of 01 March 2024) available in equine veterinary medicine from the literature. Reading this book will not turn you into a dental practitioner in any way.

Any use of this information for other than the three intents, above, is wilful ignorance. No one associated with this book in any way will be liable for any losses— physical, mental, monetary, or any other loss you can dream up. Just learn the information and use it for the betterment of you and your horse in your dealings with your chosen dental practitioner.

TRIGGER WARNING: there are images of portions of deceased horses, blood, etc., and detailed descriptions used to illustrate disease conditions. If this bothers you, do not read this book.

FOR FULL DISCLAIMER NOTICE, SEE COPYRIGHT page, and the DISCLAIMER page, which is listed in the Table of Contents.

8- My upcoming online courses for horse owners are nearly complete: one for Equine Emergency Care and another for Modern Equine Dentistry. I wanted this book published first!

If you are interested, please join my Equine Vet Today VIP list by clicking on the link or on the QR Code. This will invite you to my Equine Vet Today VIP List!

9- I am creating more books in parallel to this one, one of them is an adaptation for younger horse enthusiasts, their parents, or owners who want a less technical explanation in a shorter, handbook version.

If you have specific items you think your young friends would like to read about, or if you would be interested in a copy, please let me know by leaving a message in the Contact Us page on my veterinary website.

I also write historical and veterinary fiction (relatively horsey, of course) as Lizzi Tremayne.

You are welcome to join my:

1) Equine Vet Today VIP List by clicking here, or…

Use the QR code to sign up for the Equine Vet Today VIP list! Use the QR code to sign up for the Equine Vet Today VIP list!

2) Lizzi Tremayne Fiction Author VIP List by clicking here, or…

Use the QR code to sign up for the Lizzi Tremayne VIP list! Use the QR code to sign up for the Lizzi Tremayne VIP list!

Do you prefer real paper books? Here are a few pages from the paperback and hardback versions:

Enjoy!

Xx

Dr Elizabeth (Lizzi) Thompson

Blue Mist Holdings Ltd, DBA Blue Mist Equine Veterinary Centre

PART I

THE BOOK

CHAPTER 1

HOW DO I KNOW MY HORSE HAS DENTAL DISEASE?

Saying floating is all a horse needs is like saying if you brush your teeth, you won’t get cavities, periodontal disease, or cracked teeth.

—Jack Easley, DVM, MS, DBVP (EqPract), AVDC (Equine)

Hello and welcome! If you have not yet read the Author Preface (just before this chapter) please go back and read it! The preface is designed to give you the keys to best understand this book.

Sometimes horses show you clearly that their mouth is bothering them, or show you signs of dental pain. And sometimes they don’t, or at least not in ways we can always understand. Despite this, there are many clinical signs, or what the vet sees, which may indicate dental disease or "dental pathology". We use signs rather than symptoms, because symptoms are the signs of the disease noticed by the patient, and since the patient is a horse, herein lies the problem with using symptoms for a non-human.

The definition of pathology as it pertains to dental disease is defined by the Cambridge Dictionary as medical characteristics of a disease and a disease or medical condition. Merriam-Webster further defines pathology as the structural and functional deviations from the normal that constitute disease or characterize a particular disease.

It isn’t only the teeth themselves which may be affected by dental pathology; other seemingly unrelated problems may occur as a direct or indirect result, such as choke, colic, poor performance, recurrent fertility problems, and aggression.

By paying close attention, you may recognize subtle signs of painful dental disease. If you’ve ever had a serious toothache, you may remember how debilitating the pain can be. It probably affected your performance at work, school, or sport. Unsurprisingly, if your horse has dental pain, it may strongly influence their comfort level, and their performance, as well.

Donkey displaying green, chewed-up feed discharging from nostrils in a case of choke. Image credit Author .

What are the Clinical Signs of Dental Pain?

. Signs during work

pulling or lugging on one or both reins

resisting turns or other evasion

head tossing or head shaking

unexplained subtle lameness (see Chapter 4, Examination of the Mouth: SpecialExams: Prepurchase)

mouthing or chewing the bit

head tilt or playing with the tongue

sticking the tongue out of the mouth, or over the bit

resisting bridling

refusing to maintain a frame or vertical head carriage

sensitivity of cheeks to touch

irritability or aggression when asked to perform certain movements

These behavioral or training issues may be a sign something is amiss in your horse’s mouth, although they may be attributable to other causes like lack of effective training or problems in musculoskeletal, neurological, or skeletal areas other than the mouth. It is relatively straightforward for someone well-trained in veterinary dentistry to evaluate your horse for oral conditions which could cause these problems.

. Signs at rest in the stable or field

This 30+-year-old pony has significant dental disease but does well on grass and soaked pelleted feeds. Sometimes she manages to sneak hay from the other horses and chews it round and round, but she cannot chew it well enough to swallow the quid of twisted hay that forms in her mouth . She then has to drop these quids on the ground. Image credit Dr Laurinda Oliver .

dropping grain/hard feed, hay, or grass

quidding – dropping quids, or twisted wads of hay or grass

excessive salivation/ drooling

foul odor from mouth

head tilt while eating

grain/hard feed in water bucket

playing with tongue

whole grains in manure

> 3.5 mm hay particles in manure: increased fecal fiber length

refusal to eat or eating slowly

weight loss usually only occurs when dental disease is severe

swellings along the jaw or on the side of the face

purulent discharge from face or beneath the jaw

Manure with hay stems longer than 3.5 mm in a horse with oral pain. Image credit Author .

. The most common sign of all?

The most common sign is… NO OBVIOUS SIGNs AT ALL, or none that we notice, anyway!

Surprised? Many people are. Horses tend to be stoic and usually hide even severe dental pain. A regular, thorough, six-monthly or yearly clinical examination can identify early signs of disease, allowing your horse’s dental care to be based on examination and diagnosis, or prophylactic (preventative) dental care, as with your own dentist. Your dental vet can offer early intervention based on examination and advanced diagnostics, rather than having to resort to being the ambulance at the bottom of the cliff, attempting catch-up treatment of disease which has advanced to a severe stage where your horse may show signs of advanced clinical disease— which will be difficult, time-consuming, and expensive to treat.

But why don’t they seem to show obvious signs of what we would call pain? Read on!

Why Don’t Horses Display Obvious Pain? Or Do They?

How can the most common sign of dental disease be no obvious sign at all?

There are many potential reasons, but it’s partly because horses are a prey species, which means in their evolutionary history, they were preyed upon (eaten) by meat-eating predators. While they are sentient beings, there is no advantage in displaying that they are weak or in pain, as it would encourage these predators. Your horse may not be surrounded by hungry wolves anymore, but a few hundred years of keeping the wolves away hasn’t changed the defense mechanisms evolved in his species over millions of years. However, this is only part of the reason. I see the primary problem here is our failure to notice the subtle symptoms horses show us every day.

. Pain and the Horse Grimace Scale

Sometimes it’s hard to tell they’re in pain, but fortunately they do actually show signs of pain from dental disease—it’s up to us to learn what these look like! Several new studies have been published which look at pain faces, or a pain coding system called the Horse Grimace Scale (HGS). Many of us have known of these signs intuitively long ago, the tight muzzles and the wrinkles around their eyes, to name just a few, but finally vet researchers have looked at this and quantified the signs. Many vets and techs in veterinary hospitals are using pain scoring to recognize and quantify (determine the amount of) signs of pain in hospitalized animals. Many of the signs evaluated in the HGS may have been attributed to anger or grumpiness in the past, but people are finally recognizing them for what they are… signs of pain.

Facial expression changes have been used in human medicine for some time now. They have been adapted to equine medicine as the HGS, which has proven to be an easily learned, sensitive tool with a high reliability between different observers. HGS has been used to evaluate pain levels in different areas of the body by evaluating six characteristics of equine facial expression:

• ears held stiffly backwards

• tension above eye area

• tightening around the eye

• prominent and strained chewing muscles

• mouth strained with pronounced chin

• strained nostrils with flattening of the profile

Some of the newest papers are specific to HGS observations of horses with dental pain and are showing that dental disorders result in different levels of pain or discomfort for horses, which hadn’t been clearly demonstrated before. They found these levels of pain or discomfort could be reliably evaluated and quantified using the HGS, whether the observer was standing beside the horse or looking at photographs of the horse.

This makes the HGS extremely useful, as it can be clinically significant in the routine evaluation of horses by general practitioners and realistically, it could be utilized by owners as well! Check out the papers on it in the Bibliography and Further Reading.

Believe me, I’m sure a fractured tooth will cause him constant pain every time he chews or moves. Now, due to these studies, many other people will understand just how painful dental conditions can be! The pain caused by dental pathology is often underestimated. When your horse is asked to work, it is likely worse. Can you imagine the effect this may have upon your horse’s performance?

While signs of dental pain in captive, unhandled zoo zebras may only be evident by recognition of increased fecal fiber length and observation of facial expressions, they need dental care, too! This is Itika , a Plains Zebra at the Auckland Zoo in New Zealand , with Dr Elizabeth Thompson . Itika is having a planned odontoplasty (dental examination and tooth floating) under general anesthesia. Image credit Vanessa Marsh , used with permission of Auckland Zoo .

Think back to when you were last in serious pain from a tooth and how it affected you every moment of every day. And then realize many of us have treated horses with serious dental conditions, including fractured teeth, who were in full work up until the time they were examined. The relief they showed after extractions makes it clear how much pain they were in before the treatment. The effect of this pain cannot be underestimated.

So how do we diagnose these painful conditions? Read on!

CHAPTER 2

THERE ARE EIGHT LEVELS OF EQUINE DENTISTRY?

Many people don't understand that when you have an emergent, objectively established truth by the methods and tools of science, you do not have the luxury of standing in denial of it because it is true, whether or not you believe in it.

—Neil deGrasse Tyson

The weather is great, you have more time off, and it’s time to get that horse fit! Unfortunately, he’s doing funny things with his mouth and not taking rein contact. Is he just out of condition, or is something in his mouth bothering him?

Just as there are different ways to treat most health conditions, there are different levels of dentistry. Multiple levels of dentistry have been described, which are defined by how the examination is performed, the equipment and pharmaceuticals utilized, and the treatment itself. More information about the condition of the horse’s mouth is available at each subsequent level.

The level you select is your choice, as the owner, but it is vital you understand what those levels mean before you make your choice. Consider, as you read through this chapter and the rest of the book, what is involved at these different levels, what may be missed, and what degree of thoroughness you desire for your horse. We will come back to this question later, in Chapter 13.

What Are These Levels?

. The First Level

The First Level involves only the use of a hand float (a dental file) or a motorized power float. Information obtainable at this level is severely limited. Removal of sharp enamel points is possible in cooperative horses who will let one work without continually closing their mouth on your float. Large distal hooks and subtle problems will be missed or ignored due to the difficulty in treating them. It is difficult to remove distal hooks on the far edge of the teeth furthest back in the mouth (’11s, which you will learn about in Chapter 3) because there is often pain in the soft tissues near these hooks and horses tend to be less than cooperative when you are hurting them. There is no visibility into the mouth as it’s dark and the mouth is full of food. One may see the incisors, canines, wolf teeth and the more mesial portions of the first cheek tooth. It is difficult and unsafe to check the buccal (toward the cheek) and lingual (toward the tongue) edges of the more distal cheek teeth. These usually need the most attention but are unfortunately the most neglected. Obviously, one cannot see any detail on most of the teeth, and thus most of the pathology giving your horse problems will be missed.

At this level, one is merely waving a rasp at an unknown quantity of pathology.

Image of Dr Elizabeth Thompson and Hannah Lowry performing a hand float at the First Level of Equine Dentistry , for illustrative purpose only. Image credit Elliot Thompson .

. The Second Level

In the Second Level, a one-sided gag is added. These go by the name of Bayer, Schouppe, spool, coil, Landmeisser, wedge, and the like. They have a bite piece which fits between the cheek teeth made of either:

cylindrical spring steel or a solid metal cylinder (the spool types), or

a wedge of metal, plastic, or rubber (the wedge types).

The only benefit from using either of these types of gag is slightly easier floating of the teeth because one side of the mouth held open to some degree. However, these gags are not recommended because at best, they do not significantly assist in examination or floating, and at worst, they frequently cause serious damage. The reasons for this are as follows:

A horse masticates (chews) a lot with a unilateral (one-sided) gag in place. This makes it difficult to examine the teeth, (the primary purpose of a dental examination), which should be performed before the teeth are filed.

As the gag occupies mouth space on the side where it is placed, the tongue is pushed toward the other side where examination or floating is being attempted. This decreases visibility inside the mouth, already minimal at this level, and makes floating more difficult.

Thetemporomandibular or jaw joint, commonly known as the TMJ, may be damaged when a horse bites down hard on only one side at a time

If the gag slips from between the teeth to the inside of the teeth, the palatine arterymay be ruptured. It bleeds. A lot. For a long time.

Most seriously, however, the danger of fracturing cheek teeth is very real. The cylindrical shape of the spool types causes the entire force of both sides of the strong masseter (chewing) muscles to be focused on a narrow line across two opposing teeth, which may lead to a fractured cheek tooth or teeth, with severe consequences. A fractured tooth needs to be extracted. A fractured tooth will cause your horse a lot of pain until the tooth is actually discovered and extracted. Make no mistake, this is a major surgery, especially because that recently-healthy tooth will be firmly stuck in place. And the worst thing? The fracture never had to happen in the first place.

The image shows two of the many NON -recommended gags which are sometimes used at The Second Level : Shown are the Bayer / Schouppe (1920) and the Landmeisser . These can seriously damage teeth and other tissues, including causing fracture of cheek teeth. Unmarked image credit Dr Jack Easley .

Back to the levels, if there is any pathology at Level Two in your horse’s mouth, it will most likely be missed as well. One is still merely waving a rasp around in the