When done properly, equine dental care means more than leveling a wave, removing a hook or taking sharp points off.
Horses, like most grazing animals, have teeth that continually erupt throughout their lives. They don’t “grow” per se; the root is already formed at a young age. As a tooth wears with grazing, the eruption of reserve crown (the part under the gum you don’t see from inside the mouth) ensures there will be enough functional tooth to grind food throughout the horse’s lifetime. Proper dental care is a key aspect of maintaining your horse’s overall health and well-being.
Common tooth imbalances
Because our domestic horses do not have the genetic selection, diet and environment of true “wild” horses, their dentition is prone to uneven wear patterns. These create pain and dysfunction and can seriously impair performance and even longevity. Some of the commonly seen imbalances and resulting pathology encountered in the equine mouth include:
•retained baby teeth
•long canines (gelding only, usually)
•wolf teeth (both males and females)
•sharp points and lacerated cheek tissue
•overgrown and imbalanced incisors (overbites, etc.)
Modern equine dentistry
When I was in veterinary school, we were not taught to look at the mouths of very young horses. Nor were we told that horses need dental exams every year as part of a good preventative health program. I didn’t learn how much there actually was to equine dentistry until a friend introduced me to someone who taught at an equine dentistry school and had a lot of tools and techniques I had never even seen!
I furthered my education and, from that point on, used a full mouth speculum to ensure a complete exam and give me the ability to work in the back of the horse’s mouth. I sedated all my patients so I could help them with the least possible amount of pain and stress. I began to use a head lamp to see soft tissue structure and each and every tooth. I am likely to employ a few different power tools as well as several hand floats in order to customize my work for the needs of my patients, while reducing the work load on my own muscles.
Dentistry was done on horses over 100 years ago, but when the species transitioned out of its role in transportation, military operations and farming into that of sports competitor and companion animal the veterinary profession dropped the ball somewhere along the way. Instead of using a full mouth speculum and correcting waves, hooks and incisor imbalances, the idea arose that just “filing the sharp points off” and checking for wolf teeth was enough to keep horses in good dental health. And other than pulling wolf teeth, “floating” was not deemed necessary until horses were at least in their teens, showing signs of weight loss or resistance to the bit. The good news is that many veterinarians and the profession as a whole have picked the ball back up, and equine dentistry is now gaining recognition for its importance in horse health.
Tooth eruption and formation
We now know horses should be examined for proper dental conformation before they are a year old, checked for wolf teeth with every examination (they are supposed to erupt at six to 18 months, but I often see a bump come up under the gum much later in life), and have dental work done at least once a year.
Horses are constantly teething from the age of one to four years (and up to six years for some geldings due to canine tooth eruption). They are pretty much born with their first three baby or deciduous molars, which is why they can start eating hay very soon after birth. The central deciduous incisors show up around six days of age, the adjacent set at six weeks or so, and the corner or outermost incisors at about six months. The first adult molars show up when the horse is a year old, while the next two in the arcade erupt at approximately two and three years of age, respectively.
Between the eruption times of the last two adult molars, the central deciduous incisors are lost and the adults come in. Just after this event, which can be a very “mouthy” time for babies as the annoying teething process takes place, the first set of deciduous molars are lost and adult teeth replace them. Baby teeth continue to shed and adult teeth push up between the molars and incisors until around three-anda- half years of age. If the horse is a male, the canines will start to push through the gums on the bars when he is between four and six years old.
When does my horse need dentistry?
I recommend all horses have semi-annual dental work from at least two years of age until they are five. It’s then possible to evaluate the ideal interval for dental work in a particular horse. Every horse is different so it is best to set a schedule that changes as his needs change. Some may need work twice a year for several years, but as they get older they have fewer and fewer changes so can go longer between visits.
Too much or too little dental work can damage a horse’s mouth and health. When equine dentistry experienced a renaissance, starting about 15 years ago, many practitioners went a little “hog wild” with the power tools and took too much tooth off, leaving a flat molar table angle, or balanced the molar arcades without looking at the incisors.
Form meets function
The molar arcades function best when there are angles to the top and bottom teeth that allow them to meet and grind optimally without high spots, excessive ridges or sharp edges. It is not uncommon for horses to present with molar arcades that have been floated completely flat so they have very little contact with each other. It’s important to preserve the molars’ ability to grind hay to fine particles; filing molar arcades to a smooth surface will interfere with the horse’s ability to chew.
Don’t forget the incisors! Correcting high points, hooks or waves in the molar arcades while not evaluating how the incisors fit together can create a space between the molars. This means the horse cannot get his teeth together to chew. This is a common problem I see. It seems there is either a lack of belief about the need for incisor balance, or a lack of knowledge about its importance. Grinding off some incisor to achieve molar occlusion is imperative in many horses, and creating an even “bite” with regard to the incisors can make a huge difference in the balance of the temporomandibular joint (TMJ). However, it’s also possible to do damage by removing too much incisor or reducing incisors in a way that leaves the jaw even more out of balance than it was before.
Geriatric horses require special care of their teeth and soft tissue structures. They’re prone to periodontal disease and loose teeth, so it’s important to provide adequate pain relief and to work as gently as possible to ensure that dental procedures are not overly stressful. Older horses with severe dental imbalances are also somewhat limited in how much can or should be changed. A lot can be done to help them chew better and alleviate pain, but we may not always achieve the same kind of balance on a 20-year-old horse that we can on a much younger animal.
When done properly, equine dental care means more than leveling a wave, removing a hook or taking sharp points off. It is about creating a mouth and jaw that can efficiently chew and digest food, as well as contributing to balance and synergy in the entire body. Balancing the mouth affects energy flow in acupuncture meridians as well as the emotions, myofascial tension, cranio-sacral balance, and more. There’s an old saying: “no foot, no horse”. Those who make sure their horses receive thorough and regular dental work know that “no mouth, no horse” also applies.
Dr. Erin Zamzow graduated from Washington State University School of Veterinary Medicine in 1990. She and her family (husband Jeff and sons Ryan and Dylan) live in Washington State with their three dogs and two horses. As co-owner and formulator for VivoAnimals, LLC, Dr. Zamzow creates and distributes products to help animals return to health by “Removing the Barriers to Wellness”. She also has a private practice that focuses on equine dental health, detoxification and nutrition, and works with the Willow Creek Animal Rehabilitation Center in Ellensburg, Washington.