Horse teeth: number, age and care explained

You keep finding small balls of hay in your horse's manger, or on the ground in front of the hayrack. That detail, the one you sweep up without a second thought, is one of the most reliable warning signs of a dental problem. Horse teeth are never seen and never brushed, yet everything else depends on them: digestion, general condition, comfort under saddle, and even the age you will be quoted at the time of a sale. This guide gives you the exact number of teeth for each type of horse, the job each type of tooth does, the reason they keep growing for almost the whole of a horse's life, the method for reading its age off its incisors year by year, and the list of signs that should have you calling a professional.

How many teeth does a horse have: 36, 40 or 24 depending on the case

An adult mare has 36 teeth, an adult male horse has 40. The difference comes down solely to the four canines, present in males and absent in most mares. A foal, for its part, has 24 milk teeth, with no molars and no canines at all.

That figure of 36 comes from a perfectly regular layout. In each of the two jaws, a horse has:

• 6 incisors: two centrals in the middle, two intermediates either side of them, then two corners at the outer edges.
• 6 premolars, three on each side.
• 6 molars, three on each side.

Males, along with the mares that do grow them, carry an extra canine per quadrant, four in all. That is where the total of 40 comes from.

Vets write this layout down as a dental formula, using the modified Triadan system. It reads upper jaw over lower jaw, for one half of the mouth:

• Adult male horse: I 3/3 C 1/1 PM 3/3 M 3/3
• Mare: I 3/3 C 0/0 PM 3/3 M 3/3
• Foal: I 3/3 C 0/0 PM 3/3

One detail often puzzles people: the formula lists three premolars when the horse anatomically starts out with four. The reason is that the first premolar is usually missing. When it is there after all, it goes by a name every rider knows: the wolf tooth. More on that in a moment.

The four types of teeth and what each one does

A horse has four types of teeth: incisors, canines, premolars and molars, and each one does a very distinct job. Its mouth is described as heterodont: the teeth share neither the same shape nor the same function. Each type has a precise task, and knowing which helps you make sense of what you see in the mouth.

Incisors: cutting grass

Sitting at the front, the incisors work with the lips to grasp and cut grass. From the middle outwards they are called: the two centrals in the middle, the two intermediates flanking them, then the two corners. This naming is not decorative: those three pairs, on the lower jaw, are exactly where a horse's age is read.

Canines or tushes: a leftover

A horse can have 0 to 4 canines. In males they are commonly called tushes. They sit between the incisors and the bars, and play no part whatsoever in chewing. They usually come through at around 4 or 5 years old in males.

Premolars and molars: grinding

These are the real millstones. A horse's premolars are described as molarised: they look like molars and work alongside them. Together they form one continuous grinding surface, the dental table, which breaks plant material down into fine particles. This is where the whole quality of digestion is decided, and it is also where, out of your sight, the most common problems build up.

Wolf teeth and lower wolf teeth

The wolf tooth is that vestigial first premolar, very small, sitting just in front of the first true premolar of the upper jaw. Its far rarer counterpart on the lower jaw is called a lower wolf tooth. A horse may have two, just one, or none at all.

These teeth are no use for chewing, but they cause the rider a very concrete problem: they sit exactly where the bit lies. That is why they are traditionally removed before backing, so that no point of pain forms where the bit rests.

Between the incisors and the premolars, incidentally, runs a stretch of gum with no teeth at all, known as the bars. That is precisely where the bit sits. The area is sensitive, and the quality of the tack counts for as much here as the rider's hand: a bit and bridle that suit your horse's mouth are among the basics of comfort at work.

Why a horse's teeth keep growing for almost its whole life

Horse teeth keep growing for almost the whole of a horse's life because they are hypsodont: they hold a long reserve crown buried in the gum, which emerges as the surface wears away. It is the single most decisive feature of their anatomy, and the one that explains very nearly every problem that arises.

This continuous eruption is not a fault, it is an adaptation. A horse grazes grasses loaded with silica, which are extremely abrasive. Without renewal, its teeth would be worn out in a few years. So nature struck a balance: growth offsets wear, and wear offsets growth.

From the outside in, a horse's tooth is made up of outer enamel, cementum, dentine and inner enamel. These layers have different hardnesses and therefore wear at different speeds. That is what creates the characteristic relief of the dental table, essential for grinding, and it is also what makes the surface of the tooth readable: wear brings out patterns that change with age.

The balance holds as long as the horse chews enough. And the figures from the field speak for themselves:

• In a natural setting, a horse grazes for 15 to 20 hours a day.
• One kilo of hay means roughly 40 minutes of chewing, so 6 to 7 hours for a 10 kg ration.
• A ration made up mainly of concentrates is eaten in a fraction of that time.

The problem is not just the duration, it is the movement. A horse chews in a circular motion that is largely sideways. Long forage calls for a wide sweep; pellets, by contrast, are ground with short vertical movements. The result: the outer edges of the upper teeth and the inner edges of the lower teeth stop wearing down and turn into cutting ridges. That is exactly how sharp enamel points form.

In other words, most dental trouble in the domestic horse comes not from any weakness in its teeth, but from the gap between the diet it gets and the one its mouth was built for. It is also what makes equine anatomy so fascinating to look at once you pick up the thread: an interest that carries over nicely into the horse prints and posters people hang at home.

Reading a horse's age from its teeth: the year-by-year table

You read a horse's age from the six incisors of its lower jaw, looking in turn at their eruption, the wear on their table, then the angle of their profile. This is the oldest and the most striking use of equine dentition, and it rests on three observations in sequence.

1. Eruption: which teeth have come through, and which are still milk teeth. This is the most reliable criterion, but it only works up to about 5 years old.
2. Wear on the table: the surface of the tooth changes appearance over the years. The cup, that dark hollow in the middle of the tooth, gradually fades away. The tooth is said to be level once the cup has gone, then smooth once the inner enamel ring is no longer visible. At that point the dental star appears, a brown mark with no relief.
3. Shape and angle: the table goes from oval to round and then triangular, and the profile of the incisors, very open in a young horse, closes up over the years. A characteristic notch, the seven-year hook, appears on the corner tooth.

Here is the full sequence, as taught in the official French hippology manuals, including the Galop 8 syllabus published in 1995, and as corroborated by the reference veterinary work on equine dental ageing published in 1998 in the journal Veterinary Clinics of North America.

One word of caution is needed, and it matters. This reading is considered reliable up to 12 or 13 years old. Beyond that it is still possible, and some authors will estimate age into a horse's thirties, but the margin of error grows sharply. Several situations make it downright misleading:

• Parrot mouth, a mismatch in length between the two jaws, which throws off the whole wear pattern.
• Crib-biting, which wears the tables in a completely abnormal way.
• An unusually deep cup, which makes a horse look younger than it really is.

It is also an excellent way into the anatomy of the head and mouth, whether on a wall chart or on a detailed horse figurine when you are working towards an exam.

Yard vocabulary: mouthing a horse, dental age, retained cups

Mouthing a horse means working out its age from its incisors, and the age you arrive at is known as the dental age. There is a precise vocabulary around horse teeth, handed down from dealers and from the riding manuals, and having it at your fingertips completely changes how you follow a conversation in the yard or a sale.

• Mouthing a horse: working out its age from the eruption and the wear of the tables of the lower incisors. That is the technical term for the job.
• Dental age or trading age: the age estimated from an examination of the teeth. The distinction is crucial, this is not the horse's official date of birth.
• Retained cups: a horse whose incisors still show the cup after 8 years old. Its mouth suggests an age lower than the truth.
• Deep retained cups: the more pronounced case, where the base of the cup is still there after 12 years old.
• Seven-year hook: the dovetail notch that forms on the corner tooth, a classic marker at 7 and then again at 12.
• Dental star: the brown mark, flat and with no enamel border, that appears once the tooth has gone smooth.

This vocabulary is not just a purist's curiosity. It exists because the age read off the teeth long set the price, and where there is a price, there has been fraud. Deliberate alterations to dental tables have been documented, meant to age or rejuvenate a horse artificially ahead of a sale.

The practical conclusion fits into one rule: the mouth gives an indication, the paperwork gives the age. If you are buying, always cross-check what you read in the mouth against the horse's passport and its entry in the national equine register. A marked discrepancy between the two is not necessarily fraud, it may be a horse with retained cups, but it always deserves a question put to the seller.

Sharp points, diastema, retained caps: the most common dental problems

Sharp enamel points, diastema and retained caps are by far the three most common dental problems in horses. Conditions affecting horse teeth are widespread but largely under-diagnosed, because the signs are subtle and the area involved stays invisible without equipment. Here are the cases practitioners meet most often.

Sharp enamel points are by far the most frequent. They classically form on the outside of the upper cheek teeth and the inside of the lower ones. These cutting ridges cut into the cheek and the tongue. They are corrected by floating, carried out by a professional.

Diastema is an abnormal gap between two teeth. Food packs into it, ferments, and sets off an inflammation of the gum that can develop into infection, going as far as loss of the tooth or even involvement of the jaw bone. It is a painful situation and one for the vet.

Retained caps affect young horses. The milk tooth fails to drop and stays hooked on the permanent tooth coming through beneath it, which inflames the gum and can push the adult tooth out of line. Having a practitioner take it off avoids a lasting misalignment.

Caries occur in horses too, through the same bacterial mechanism as in humans.

Bite defects come from a difference in length between the two jaws. When the upper jaw sits too far forward, the horse is said to have a parrot mouth; in the rarer opposite case, the horse is sow-mouthed. Wear becomes uneven and needs monitoring.

A missing tooth creates a mirror-image mechanical problem: with nothing to meet it, the opposing tooth keeps erupting without ever wearing down, and ends up forming a genuine step on the dental table that blocks the chewing action.

The older horse, finally, often has several of these problems at once, made worse by years without attention. The outcome is nearly always the same: chewing becomes ineffective and the horse gradually loses weight. Dental problems are, in fact, among the leading causes of condition loss in horses.

In every one of these cases without exception, the owner's role stops at observation. None of these situations is treated at home, and none can be diagnosed with any certainty without a full oral examination.

The warning signs to watch for in your horse

Balls of hay spat out, whole grains in the droppings, unexplained weight loss and a sudden refusal of the bit are the signs that should have you getting your horse's mouth examined. Here is the checklist to keep in mind. No single one of these signs is enough for a diagnosis, but every one of them justifies having a look.

• Check the manger and the ground after every forage feed. Finding balls of hay spat out is the most telling sign of all: a horse cut by a sharp point balls up forage and wedges it against the sore spot, like a dressing, before dropping it. Few owners know about this behaviour, and yet it is there in plain sight.
• Watch the chewing: a horse eating unusually slowly, tilting its head to one side or dropping whole mouthfuls is telling you it is uncomfortable.
• Check the droppings: whole grains or long strands of forage mean the grinding is no longer being done properly.
• Take note of repeated episodes of choke, often linked to feed that has not been chewed enough.
• Keep an eye on body condition: weight loss with no identified cause should always turn your thoughts to the teeth.
• Listen in the stable: repeated teeth grinding is never trivial.
• Smell the breath: a strong, persistent odour, what practitioners call halitosis, points towards infection.
• Note nasal discharge from one nostril only, which can signal a dental problem that has tracked up into the sinuses.
• Check the behaviour at work: refusing the bit, resistance under saddle, a neck that stiffens, a head thrown up, or a horse that goes hard on one side with no mechanical reason for it.

These observations simply take time spent with your horse. Daily grooming is still the best moment for it, and a complete grooming kit turns that routine into a genuine health check.

One rule to close on: if you are in any doubt, get it looked at. A check-up that finds nothing costs infinitely less than a lost tooth.

Dental care: who does it, when and how

Dental care rests on one mouth check a year, carried out either by an equine vet or by an equine dental technician. Looking after horse teeth is basic care, on a par with trimming the feet or the annual visit from the vet. Yet it remains the most neglected of the three, precisely because a sharp point, unlike a cracked hoof, cannot be seen.

Two professionals can step in: the equine vet and the equine dental technician, commonly called an equine dentist. Both carry out the oral examination, the rasping and the removal of wolf teeth or caps. The split of responsibilities is strict, however, on three points:

• Sedation and local anaesthesia are for the vet alone.
• Extracting a premolar or a molar is a complex surgical procedure, again for the vet alone.
• All other dental procedures are likewise the vet's remit.

In practice, a session always follows the same pattern. The practitioner fits a gag, a mouth speculum that holds the jaws apart, which lets them examine the cheek teeth, the tongue and the inside of the cheeks. They then assess the dental table and, if needed, carry out the floating with a hand rasp or a powered one. Sedation is sometimes necessary, not because the procedure hurts, but because the noise and the sensation unsettle the horse, and a horse that will not stand still cannot be treated safely.

One point deserves underlining, because it is poorly understood: rasping must not be too invasive. A horse needs a minimum of relief on its tables in order to grind efficiently. Excessive levelling harms chewing rather than improving it. A horse treated properly should show no sign of discomfort afterwards.

As for frequency, the sound rule is the annual check, bearing in mind that rasping is not automatically needed at every visit. Better to have a healthy mouth checked than to let another year go by on a mouth that needed the attention.

The frequency is then adjusted to the individual horse:

• Foals and youngsters under 2: a check alongside their other routine care, then moving to a yearly rhythm.
• Horses from 2 to 5, in the middle of changing their teeth: every 6 to 12 months, this being the risk period for retained caps.
• Adult horses from 6 to 17: once a year.
• Horses over 18: once a year at the very least, more often if they start losing condition.
• Horses working in a bit: once a year, and without waiting if a new resistance appears.

One last reflex for the ridden horse: when resistance suddenly turns up at work, the mouth deserves a look before you start questioning the schooling or the riding equipment. A bit should stay a tool for communication, never a source of pain in a mouth that has been damaged.

Frequently asked questions about horse teeth

Here are the six questions riders and owners ask most often about horse teeth, each with a straight answer.

How many teeth does a horse have on average?

An adult horse has between 36 and 40 teeth. A mare has 36: 12 incisors, 12 premolars and 12 molars. A male horse has 40, because he also carries 4 canines, known as tushes. Some mares do develop canines and fall somewhere between the two. On top of that there may be one or two wolf teeth, those tiny vestigial premolars that not every horse has.

How do you tell a horse's age from its teeth?

You look at the incisors of the lower jaw, checking first which permanent teeth have come through, then the wear on their table, then the angle of their profile. The permanent centrals come through at around 2 and a half, the intermediates at around 3 and a half, the corners at around 4 and a half. After that you follow each pair as the cup goes and the tooth turns smooth. The reading is reliable up to 12 or 13 years old, and becomes an estimate beyond that.

At what age does a horse lose its milk teeth?

The milk teeth appear as early as the first week of life and a foal has 24 of them. They are gradually replaced between 1 and 5 years old, in this order: the centrals at around 2 and a half, the intermediates at around 3 and a half, the corners at around 4 and a half. The permanent mouth is considered complete at around 6 years old. A healthy adult horse does not normally lose teeth any more, barring infection, trauma or old age.

What does the mouth of a 3 or 4 year old horse look like?

At 3, a horse has its permanent centrals, easy to spot because they are wider and yellower than the milk teeth beside them, while the intermediates and corners are still milk teeth. At around 3 and a half, the permanent intermediates come through in their turn. At 4 and a half, it is the corners. So a 4 year old has a mixed mouth, right in the middle of the changeover, which makes this the easiest period to date and also the one most exposed to retained caps.

What is a wolf tooth and does it need removing?

A wolf tooth is a vestigial first premolar, very small, sitting on the upper jaw just in front of the first true premolar. Its rarer lower counterpart is called a lower wolf tooth. It plays no part in chewing. Because it sits where the bit passes, it is traditionally removed before backing to avoid any point of pain. The decision rests with the vet or the equine dentist, depending on its position and size.

How much does dental treatment cost for a horse?

The question of price comes up a lot, and it is about the procedure rather than the tooth itself. The cost of an oral examination with rasping varies with the region, the practitioner, whether or not sedation is used, and the number of horses seen at the same yard. Ask a practitioner in your area for a quote, and remember to group the visit with other horses on the yard, which almost always brings the call-out cost down. Set against the price of lost condition or an extraction, an annual check remains one of the best investments in a horse's budget.

Your horse's teeth work in silence, several hours a day, for its whole life. They ask for only one thing: an attentive glance into the manger, and one appointment a year.