In this Article:
Anatomy of the Horse's Mouth
Horses, donkeys, and mules have hypsodont teeth (see right), which continue to grow until they reach five to seven years of age. Although the teeth are done growing, they continue to erupt from the gum line by two to three millimeters per year. Equines do not produce more tooth matter throughout their lives, so there is a finite amount available.
Another unique feature of equine dentition is that the lower jaw (mandible) is narrower than the upper jaw (maxilla) resulting in a slanted (occlusal) chewing surface.
There are many factors that affect the wear of the teeth, including diet (grazing vs stall feeding), environment (e.g. sandy soil), and occlusion (e.g. how their teeth fit together).
Like humans, horses have two sets of teeth; baby (deciduous) teeth and adult (permanent) teeth. By nine months of age, foals have all of their baby teeth (24 of them!). Their first adult teeth start coming in around one year of age, and as they erupt, the baby teeth (also called "caps") get pushed out, much the same as human children.
Horses typically have their complete set of permanent teeth by age five. Male horses generally have 40 permanent teeth, while most mares have around 36, as mares only rarely have canine teeth.
Chew on These Anatomical Terms
Having tall crowns & short roots
Upper jaw is wider than lower jaw
Having teeth of different shapes, such as molars & incisors
Having deciduous & permanent teeth
Anatomy by the Numbers
12 .............. Incisors ....... Used to nip grass & feed, for defense, and for grooming
12 .............. Premolars ... Used for grinding roughage & feed
12 .............. Molars ......... Used for grinding roughage & feed
0, 2, or 4 ... Canines ........ "Fighting teeth," typically in all male horses, uncommon in females, have no purpose in processing feed
0 to 4 ........ Wolf Teeth .... Vestigial premolars, most often males & females will have 2 on the top jaw but may have none or up to 4;
have no purpose in processing feed
In addition to all the "hardware" in their mouth, horses have a variety of soft tissues including their lips, tongue, cheeks, and palates. All of these components allow the horse to grab, position, and move the feed that their teeth are grinding.
HOW WILL I KNOW WHEN MY HORSE NEEDS A DENTAL?
We recommend a thorough dental exam annually. Preventative dentistry is a crucial step in helping your horse to live a long, happy, and healthy life. Many horses do not show signs of discomfort until their oral problems becomes severe so an annual exam is imperative.
The following signs can be indicative of dental abnormalities:
Taking longer to eat their normal amount of feed
Dropping feed out of their mouth
Leaving 'quids' (chewed up pieces of grass or hay) in their stall or paddock
Unwillingness to take the bit, or resistance under saddle
Excessive nasal discharge
WHY DOES MY HORSE NEED REGULAR DENTAL CARE?
As described earlier, horse's teeth continue to erupt throughout their life. Despite this ongoing growth, they have only a finite amount of reserve tooth available. As such, abnormal dental conformation and other problems can speed up the wearing process, leading to early tooth loss and other systemic problems (such as colic) from being unable to effectively chew their food.
Horses chew in a circular motion. To ensure all horses have proper excursion (side to side movement of their jaw), our dental exams involve not only "floating" of the sharp points, but also occlusal equilibration. This term, simply put, describes the adjustments made to affect the way the upper and lower teeth fit together during chewing. Maintaining proper occlusion throughout a horse's life can significantly prolong the longevity of their teeth.
The most common problem seen in horse's mouths is sharp enamel points. These sharp points typically form on the inside of the lower teeth and the outside of the upper teeth. As these points grow, they can cause ulcers to form on their cheeks and tongue and may interfere with bridle contact while riding. Horses with painful mouths will often show bad behavior under saddle or may be hard to put weight on.
Although points are the most common abnormality we deal with in horse's mouths, there are many other problems which can occur. Below is a list of a few:
Abnormal incisor wear
Overjet & Underjet → hooks & ramps
Periodontal disease, feed packing and tooth loss
WHAT TO EXPECT: YOUR HORSE'S DENTAL FLOAT
A full physical exam is strongly suggested prior to any dental procedure. The veterinarian will listen to your horse's heart, lungs, and gastrointestinal tract, examine their eyes, and take their temperature. She does this to check for heart murmurs, lung disease, and fevers, and to ensure your horse is healthy enough for sedation. A brief, unsedated oral exam is then performed so that the veterinarian can survey the mouth and determine what level of work will be needed.
To prepare for the dental float, your horse will be given an intravenous sedative to the point of standing sedation; a term used to describe a decreased state of awareness, yet not so anesthetized that the horse can't remain upright. The sedative ensures the dental float can be performed safely and quickly for the veterinarian, and without undue emotional stress on the animal. The sedative most commonly used, Detomidine, is in full effect for about 45 minutes, but it can take up to two hours for your horse to be completely awake following the procedure.
Once your horse has reached an appropriate plane of sedation, their mouth will be rinsed with a dilute chlorhexidine (a veterinary antiseptic) solution to remove any leftover feed. A dental speculum will then be placed on their head, which allows the veterinarian to view the back of the mouth. A visual and manual exam of the mouth will then be performed, making a detailed assessment of any problems which need to be addressed.
A PowerFloat is then used to reduce any sharp enamel points present, and to balance the dental arcades. Once all cheek teeth work is complete, the speculum is removed, and the excursion (side to side movement of the jaw) is checked to ensure optimal motion. At this time, added work may be necessary on the cheek teeth or incisors to provide more fluid movement. Once the entire float is complete, the mouth is rinsed again to remove all the tooth dust created during the resurfacing of the molars.
Following the dental procedure, you will receive detailed notes from your veterinarian on all abnormalities and any corrections made, along with recommendations for rechecks and future dental floats.
Tools and Terms in
A level of sedation that provides decreased awareness, while maintaining a standing position.
A tool used to prop open the horse's mouth to provide a full visual of all areas of the mouth.
A motorized tool for removing sharp points and hooks from chewing surfaces.
The side-to-side motion of the jaw.
TOOLS OF THE TRADE
Hand vs. Power Floats
There is a significant amount of controversy and misunderstanding surrounding the use of motorized dental equipment in equine veterinary dentistry. Power tools have allowed for the advancement of veterinary dentistry, but have also received some bad press when complications arise with their use by inexperienced or untrained hands. There are many advantages to using power equipment, in our case the PowerFloat, when they are operated by properly trained professionals. A major advantage is:
Faster, More Precise Correction of Dental Abnormalities.
When using hand floats, the veterinarian must use brute strength to physically remove the points or elevations in the teeth, which can result in a prolonged, exhausting experience for both the vet and the horse. With power instruments, veterinarians can perform more precise corrections faster and with less stress to both parties. The small heads of the power float allow access to the furthest reaches of your horse's mouth far more easily than traditional hand floats.
However, depending on practitioner preference and clinical situation, both types of equipment might be used. At Tacoma Equine, we typically perform the primary floating procedure with the PowerFloat but may use hand floats when appropriate and depending upon the situation.
Sedation and Speculum Placement Allows For the Most Thorough Oral Examination.
Sedation is often required for power floating due to the additional noise created, but this is actually an advantage of this equipment. While sedated, the patient can have a very thorough oral examination, complete with palpation of dental and gingival surfaces to ensure no subtle abnormalities are overlooked. Appropriate oral records can also be created and maintained.
Mirrors, Periodontal Probes, and Other Equipment Assist in Diagnosing and Treating Dental Abnormalities and Disorders.
From removing teeth to examining and cleaning diastemas, specialized equipment is an important component of the veterinarian's dentistry arsenal.
Dental mirrors allow for better examination of the teeth and gums, especially towards the rear of the mouth.
Periodontal probes are useful to examine areas of the teeth that appear abnormal or pockets between teeth that could be resulting from oral decay.
A Water Pick aids in cleaning out diastemas, or gaps between teeth, so a more thorough exam of the area can be performed.
Molar pullers allow veterinarians to remove loose teeth which will result in decreased oral pain.
Digital Radiography Enables Visualization of Tooth Roots and Dental Structures.
Some horses may develop dental diseases, such as a tooth root abscess, or broken teeth. Digital X-Ray can allow veterinarians to assess the tooth structure and surrounding bone to determine the cause of chronic oral pain. They are then able to consult with veterinarians who specialize in complex dental procedures and develop an appropriate treatment plan.
Equine dentistry has moved beyond simply rasping the sharp points off the tooth with a hand float thanks to advancement is dental tools, including motorized equipment and specialized instruments made for the horse's mouth!
It is important to remember that every procedure and every piece of equipment carries some degree of risk if used improperly. Most veterinarians are extensively trained in the appropriate use and maintenance of their equipment, and take every precaution to prevent complications.
WHAT IS AN "EQUINE DENTIST?"
In the state of Washington, veterinary dentistry is a practice that legally can only be provided by a licensed veterinarian or a licensed veterinary technician under the direct supervision of a veterinarian. However, there are many non-veterinarian individuals out there practicing dentistry illegally and calling themselves "Equine Dentists." This term can be very misleading, as these individuals are not licensed or insured, nor do they necessarily have any formal training in equine dentistry.
Beyond the issues of legality, are the risks to your horse's health when using a non-veterinary equine dentist, as the treatment of many dental conditions requires concurrent management of pain, inflammation, infection and occasionally systemic disease. Further, in order to provide a thorough dental examination and the appropriate treatments, sedation is often necessary, and only a licensed veterinarian can legally obtain and administer such medications.
Veterinary training is a pre-requisite for equine dental care, ensuring that the standard of care put forth by the American Veterinary Medical Association (AVMA) and American Association of Equine Practitioners (AAEP) is met.
Our goal is to help you to make the most informed choices possible regarding your horse's care to ensure they receive the best and safest treatments available.