by Drs. Dean Scoggins, Jack Easley, W. Leon Scrutchfield, with Rahel Klapheke
A ton of teeth
The adult male horse has up to
44 permanent teeth, and a mare may have between 36-40
permanent teeth. Like humans, horses get two sets of
teeth in their lifetime. The baby teeth, also known as
deciduous teeth, are temporary. By age five, most horses
will have their full set of permanent teeth.
Why so many? Evolution has designed the horse's skull
to accommodate greater quantities of high-fiber forage
foods. The horse's Eocene ancestor stood a little over
two feet tall. Modern equus are now almost triple that
height and require 27 times more food! An amazing
grinding system of the horse's teeth accommodates such an
increase in food intake and processing.
Elongation of the head and neck allowed for continual
pastural grazing; increasing the height and complexity of
the tooth shape. The forward teeth, known as incisors,
function to shear off forage. The cheek teeth, including
the molars and premolars with their wide, flat, grooved
surfaces, easily grind the feed to mash before it is
Biting the basics
To help appreciate the horse's distinct eating
process, let's follow the path of the food particle.
First, the food touches the lips. Sensitive upper and
lower lips are the integral structures for feed
apprehension. During grazing, the lips are drawn back to
allow the incisor (front central teeth) to sever the
grass at the base.
Once the food enters the mouth, the horse begins
mastication, or chewing, of the food by grinding it. This
occurs by moving the mandible, or jaw, in a side-to side
chewing movement; not up and down.
Chewing takes place where the molars are aligned in
the skull, also known as the "molar arcade."
After several minutes of chewing, the food softens and is
suitable for swallowing.
Horses are selective eaters; they prefer grasses and
legumes but a wide variety of shrubs, herb, woody plants
and even roots may be selected. They tend to avoid eating
grass in areas polluted with manure or horse urine.
The horse is a continuous grazer; that is, both
confined horses in a stall and free-ranging animals
usually eat 10-12 hours daily for 30-180 minute intervals
if hay or pasture is available.
However, full confinement to a stall does affect
eating behavior. Confined horses fed concentrate or
pelleted feed eat more rapidly and spend the remaining
time in boredom (i.e. standing, lying down, searching for
food, chewing wood, etc.). Horses confined and not
allowed access to pasture don't use incisor teeth for
shearing and this may lead to incisor overgrowth.
This is where your equine veterinarian comes in. Many
arbitrary practices such as training techniques and full
boarding change natural functions in the horse's mouth.
Dental problems can continually worsen unbeknownst to the
owner or trainer. The horse may begin to resist the bit,
not respond to common training techniques or even lose
weight and the trainer may never consider that it may be
a dental problem. From floating to filling, your
practitioner can help you develop a dental hygiene
program for your horse to help put "power
steering" in your horse's mouth.
The techniques used to float teeth vary between
practitioners. Some veterinarians will sedate the horse
and use a full-mouth speculum to allow greater
thoroughness in the examination and more precision in
performing corrective procedures.
But floating teeth is just one of many procedures that
may be available from your veterinarian. Many other
dental problems can develop and go undetected until
severe pain becomes obvious.
Recap on caps
Deciduous (baby) teeth all should be replaced by the
age of five years. Sometimes, however, these teeth are
not shed and cause a "retained cap." This
condition can cause inadequate chewing, anorexia (loss of
appetite) and poor performance.
Your veterinarian can extract the deciduous premolar
or incisor once the boundary between the deciduous and
permanent tooth is visible. If the baby tooth is
extracted too early, though, the permanent tooth can be
As the name suggests, canine teeth are sharp, tall
teeth used for tearing food. Canines are primarly found
in the male horse and can become too tall and sharp;
increasing the risk of laceration to other horses when
playing, chance of injury by catching on fixed objects,
and difficulty in inserting and removing the bit. A
veterinarian can shorten tall and rasp sharp canine teeth
to prevent these occurrences.
More than just a toothache
Just like you, your horse can have many other problems
with his dental hygiene. Common ailments horses suffer
include loose and/or broken teeth, excessively worn
teeth, infected teeth and gums and even gum disease.
It is important to catch dental problems early.
Waiting too long may increase the treatment needed or may
even make remedy impossible.
If a horse starts behaving abnormally, dental problems
should be considered as a potential cause. Horses with
dental problems may show obvious signs, such as pain or
irritation of the mouth. Other indications of dental
- loss of feed from mouth while eating
- difficulty chewing or excess salivation
- loss of body condition
- large, undigested food particles in manure
- head tilting or tossing, bit chewing, tongue
lolling, fighting the bit or resisting the bridle
- bucking or failing to stop or turn
- foul odor from mouth or nostrils
- traces of blood in mouth
- nasal discharge or swelling of the face
Other horses may show no noticeable signs because they
simply adapt to their discomfort. For this reason, have
your veterinarian thoroughly examine and float your
horse's teeth at least once a year. This dental exam
provides the opportunity to perform routine preventative
dental maintenance and avoid having relatively minor
problems become serious in the future. The end result is
a healthier, more comfortable horse.