Senior Horse Dental Problems: What Long in the Tooth Really Means

By Dr Duncan Houston

Older horses often become quieter, steadier, and wiser with age. Unfortunately, their teeth do not always age as gracefully as the rest of them.

A senior horse who drops hay, chews slowly, loses weight, avoids hard treats, smells bad around the mouth, or develops one-sided nasal discharge may be dealing with dental pain or reduced chewing ability. Some changes are part of ageing. Others are painful, progressive, and need treatment.

The phrase “long in the tooth” comes from the way a horse’s teeth change with age. Horses do not have teeth that grow forever in the simple sense. They have long-crowned teeth that continue to erupt as the chewing surface wears down. Eventually, the reserve tooth runs out, the grinding surface becomes less effective, and the mouth can no longer do the job it once did. MSD Veterinary Manual notes that horse teeth continue to erupt through life to compensate for wear from grazing. (MSD Veterinary Manual)

The key is knowing when dental ageing is normal, when it is affecting nutrition, and when your senior horse is quietly living with mouth pain.

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Quick Answer

“Long in the tooth” means a horse’s teeth have changed with age as they erupt and wear down over time. In senior horses, this can lead to worn teeth, missing teeth, loose teeth, periodontal disease, quidding, weight loss, choke risk, and painful conditions such as equine odontoclastic tooth resorption and hypercementosis, or EOTRH. Older horses should have regular veterinary dental exams, and many need diet changes such as soaked senior feed, soaked hay pellets, or chopped forage when chewing long-stem hay becomes difficult. (AAEP)

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What Does Long in the Tooth Mean?

“Long in the tooth” originally refers to visible changes in horse teeth as they age.

Horses have hypsodont teeth, meaning their teeth have long reserve crowns below the gumline. As the chewing surface wears down, more tooth gradually erupts into the mouth. This helps young and middle-aged horses cope with years of grinding fibrous forage.

But the system has a limit.

Over time, the reserve crown becomes depleted. The teeth may become shorter, smoother, narrower, loose, or less effective at grinding. In very old horses, there may be little useful tooth left.

So the phrase sounds like the horse has too much tooth, but the real senior problem is often the opposite: not enough functional grinding surface.

That is where nutrition starts to suffer.

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Why Do Senior Horses Get More Dental Problems?

Older horses have had more years of chewing, more years of uneven wear, and more time for small dental problems to become big ones.

Common senior dental issues include:

• Worn chewing surfaces

• Missing teeth

• Loose teeth

• Overgrown opposing teeth

• Sharp enamel points

• Hooks, ramps, waves, and step mouth

• Gaps between teeth, called diastemata

• Feed packing between teeth

• Periodontal disease

• Tooth root infection

• Fractured teeth

• EOTRH affecting incisors and canines

AAEP notes that dental problems can affect feeding efficiency, cause pain, and contribute to behaviour issues such as head tossing, resistance to the bit, and difficulty turning. (AAEP)

In practice, the most important thing is not the horse’s age on paper. It is whether the mouth can still chew enough forage comfortably to maintain weight, hydration, and gut health.

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What Signs Suggest Dental Pain in an Older Horse?

Senior horses are very good at quietly adapting. They may eat more slowly, choose softer feed, dunk hay in water, or avoid chewing on one side long before they look obviously unwell.

Watch for:

• Dropping feed while eating

• Quidding, where balls of partially chewed hay fall from the mouth

• Slow chewing

• Weight loss despite a good appetite

• Poor topline or reduced condition

• Long hay fibres in manure

• Bad breath

• Drooling

• Reluctance to eat hay

• Preference for soaked or soft feed

• Avoiding carrots, apples, or hard treats

• Head tilting while chewing

• Packing feed in the cheeks

• Swelling of the jaw or face

• One-sided nasal discharge

• Resistance to the bit

• Head tossing or abnormal head carriage

Merck Veterinary Manual lists difficulty or slow feeding, reluctance to drink cold water, stopping and starting while chewing, head positioning as if painful, excessive drooling, bad breath, weight loss, poor coat condition, facial swelling, and one-sided nasal discharge as possible signs of equine dental disease. (Merck Veterinary Manual)

A useful rule: if an older horse is losing weight but still seems interested in food, the teeth deserve a proper look.

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How Worried Should You Be?

Dental ageing is common, but pain, weight loss, infection, and inability to chew are not things to ignore.

Severity	What It Looks Like	What It May Mean	What To Do
Mild	Slightly slower eating, mild feed dropping, otherwise bright and maintaining weight	Early dental wear, sharp points, mild chewing inefficiency	Book a routine dental exam
Moderate	Quidding, weight loss, bad breath, avoiding hard feed, long fibres in manure	Worn teeth, missing teeth, periodontal disease, painful chewing	Arrange a veterinary dental exam soon and review diet
Severe	Marked weight loss, facial swelling, one-sided nasal discharge, loose teeth, foul smell, obvious pain	Tooth root infection, periodontal disease, fractured tooth, advanced dental disease	Call your vet promptly
Critical	Unable to eat or drink, choke signs, severe swelling, fever, depression, severe pain, rapid deterioration	Emergency dental or systemic problem	Seek urgent veterinary care

The real concern is not just the appearance of the teeth. The concern is whether the horse can chew, swallow, drink, maintain weight, and live comfortably.

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What Is EOTRH in Senior Horses?

EOTRH stands for equine odontoclastic tooth resorption and hypercementosis.

It is a painful, progressive dental disease seen mostly in middle-aged and older horses. It usually affects the incisors and canines, although cheek teeth can occasionally be involved. The disease involves destruction of tooth structure by odontoclasts and abnormal build-up of cementum around the tooth roots. UC Davis describes EOTRH as a progressive condition in older equines that predominantly affects the incisors, with surgical removal sometimes recommended and many horses improving in quality of life after surgery. (Center for Equine Health)

Signs of EOTRH may include:

• Red or swollen gums around the incisors

• Gum recession

• Bulbous swelling around tooth roots

• Draining tracts along the gumline

• Loose incisors

• Broken incisors

• Bad breath

• Drooling

• Head shyness

• Avoiding carrots or apples

• Difficulty grazing

• Reluctance to bite down

• Weight loss in advanced cases

MSD Veterinary Manual notes that severe EOTRH signs can include gum recession, incisor gingivitis, draining tracts, tooth crown fractures, discomfort when incisors are manipulated, and that diagnosis and staging depend on radiographs. (MSD Veterinary Manual)

This is one of the big senior horse dental conditions owners should not miss.

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Why EOTRH Is Easy to Miss

EOTRH can progress slowly. Many horses do not scream about mouth pain. They simply change their behaviour.

They may stop biting carrots.
They may graze less efficiently.
They may become difficult to bridle.
They may object when the lips or incisors are handled.
They may lose weight gradually enough that everyone gets used to the new normal.

In practice, the mistake I see most often is assuming that an old horse is just “slowing down” when they are actually avoiding pain.

A horse with EOTRH may still chew hay with the cheek teeth, so appetite can look normal until the disease is advanced. That is why looking only at whether the horse eats dinner can miss the problem.

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Do Old Horses Really Run Out of Teeth?

In a practical sense, yes, some do.

Horses are born with a finite amount of tooth reserve. As the teeth erupt and wear over many years, the reserve crown is gradually used up. Eventually, some teeth may become smooth, short, loose, or lost.

When cheek teeth lose their grinding function, long-stem hay becomes difficult to process. The horse may chew and chew but fail to break the fibre down enough. That leads to quidding, weight loss, poor digestion, and sometimes choke.

This does not mean the horse is doomed.

Modern feeding options can support many horses with poor teeth extremely well. The goal is to stop expecting a worn-out mouth to handle the same diet it managed at age twelve.

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What Happens When a Horse Cannot Chew Hay Properly?

Hay is built for grinding. If the teeth cannot grind it, the rest of the digestive system has to deal with larger fibre particles.

Possible consequences include:

• Quidding

• Weight loss

• Reduced fibre intake

• Poor body condition

• Increased choke risk

• Longer fibres visible in manure

• Reduced feed efficiency

• Frustration or fatigue while eating

• Greater risk of gut upset if diet changes are made poorly

Long fibres in manure can be a useful clue. It suggests the horse is not grinding forage well enough before swallowing.

The key decision point is this: if your senior horse is quidding hay, losing weight, or passing obvious long fibres, do not just feed more hay. Change the form of the forage.

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How Should You Feed a Senior Horse With Poor Teeth?

Feeding depends on what teeth remain, whether the horse can graze, and whether they are maintaining weight.

Useful options include:

• Soaked senior complete feed

• Soaked hay pellets

• Soaked hay cubes

• Chopped forage

• Beet pulp where appropriate

• Soft mashes

• More frequent smaller meals

• Good access to water

• Diet review with your vet or equine nutritionist

Rutgers Equine Science Center recommends soaked hay cubes, beet pulp, and pelleted or extruded feeds for older horses with chewing difficulty, with enough water added to create a soupy consistency to help reduce choke risk. (Equine Science Center)

A complete senior feed can be very useful because it is designed to replace part or all of the forage and concentrate ration when chewing is limited. But it must be fed according to the label and adjusted to the horse’s body condition, workload, and medical issues.

The most common feeding mistake is using senior feed like a small supplement when the horse actually needs it as a major calorie and fibre source.

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Should You Soak Senior Feed or Hay Pellets?

Often, yes.

Soaking can make feed easier to chew and swallow. It also helps increase water intake, which is useful for older horses.

Soaking is especially important when feeding:

• Hay pellets

• Hay cubes

• Beet pulp

• Large senior feed meals

• Horses with missing teeth

• Horses with previous choke

• Horses that bolt feed

• Horses with poor saliva production or poor chewing

Soaked feed should be wet enough to break apart properly, not just sprinkled with water for decoration. Dry pellets can still swell and form a dense bolus if the horse does not chew them well.

If your senior horse has a history of choke, ask your vet for a specific feeding plan rather than guessing.

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Do Senior Horses Need More Frequent Dental Exams?

Usually, yes.

Young and healthy adult horses often have routine dental exams yearly. Older horses, especially those with missing teeth, wave mouth, periodontal disease, EOTRH, or weight loss, may need checks every 6 months.

AAEP’s equine dentistry resource says horses should have dental exams at least once a year, and horses over 10 may need more frequent visits, especially if they have dental issues. (AAEP)

A proper senior dental exam may include:

• Sedation

• Full-mouth speculum

• Bright light

• Oral mirror or endoscope

• Palpation of teeth and gums

• Checking for loose or fractured teeth

• Assessment of chewing surfaces

• Evaluation of periodontal disease

• Incisor and canine assessment

• Radiographs if EOTRH or tooth root disease is suspected

A quick look at the front teeth is not a senior dental exam. That is just horse lip sightseeing.

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Why Sedated Dental Exams Matter

Many serious dental problems sit far back in the mouth, where you cannot see them safely without proper equipment.

Sedation and a speculum allow the vet to assess the cheek teeth, gums, tongue, cheeks, bars, and spaces between teeth. It also allows painful or loose teeth to be examined more safely.

Without a proper exam, it is easy to miss:

• Loose cheek teeth

• Tooth fractures

• Periodontal pockets

• Feed packing

• Sharp points

• Hooks or ramps

• Tooth root infection

• Diastemata

• EOTRH

• Painful incisors or canines

• Oral masses or wounds

This matters even more in senior horses because the mouth is often less forgiving. Aggressive floating of already worn teeth can remove tooth surface the horse cannot spare. Senior dentistry should be careful, conservative, and diagnostic, not just “rasp everything flat.”

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When Should a Senior Horse Have Dental Radiographs?

Radiographs are useful when disease is below the gumline or inside the tooth root.

They may be recommended if your horse has:

• Suspected EOTRH

• Loose incisors or canines

• Facial swelling

• One-sided nasal discharge

• Tooth root infection

• Fractured teeth

• Draining tracts

• Unexplained weight loss with dental signs

• Severe periodontal disease

• A tooth that may need extraction

• Pain that does not match what is visible in the mouth

For EOTRH, radiographs are especially important because visible changes may underestimate the disease. MSD notes that EOTRH diagnosis and staging depend on radiographic evaluation. (MSD Veterinary Manual)

The mouth can look only mildly abnormal while the tooth roots are having an absolute disaster underground.

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When Should Teeth Be Extracted?

Extraction is not about making the mouth look tidy. It is about removing painful, infected, loose, fractured, or nonfunctional teeth that are harming the horse.

Your vet may recommend extraction for:

• Painful EOTRH incisors

• Loose teeth

• Infected teeth

• Fractured teeth

• Teeth causing severe periodontal disease

• Nonfunctional teeth causing trauma

• Overgrown teeth with no opposing tooth

• Teeth associated with draining tracts or sinus infection

For advanced EOTRH, extraction of affected incisors can dramatically improve comfort. UC Davis notes that most patients experience an overall improvement in quality of life after surgery and that many horses learn to graze without incisors by using their lips and tongue. (Center for Equine Health)

Owners often fear incisor extraction because it sounds drastic. But a painful tooth that remains in the mouth is not kinder than a missing tooth. Comfort matters more than cosmetics.

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Can a Horse Eat Without Incisors?

Many horses can do surprisingly well without incisors, especially if their cheek teeth still grind normally.

Incisors are mainly used to bite off grass. Cheek teeth do the grinding. After incisor extraction, some horses need dietary adjustment, but many adapt well by using lips and tongue to gather feed. UC Davis reports that many horses learn to graze even without incisors. (Center for Equine Health)

However, if a horse also has poor cheek teeth, the feeding plan becomes more important.

A horse with missing incisors but good cheek teeth may graze and chew fairly well.
A horse with missing incisors and poor cheek teeth may need soaked complete feeds and forage replacement.

This is why the whole mouth needs assessing, not just the front teeth.

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What Else Can Cause Weight Loss in an Older Horse?

Dental disease is common, but it is not the only cause of weight loss.

Important rule-outs include:

• PPID, also called Cushing’s disease

• Parasite burden

• Poor-quality forage

• Inadequate calories

• Chronic pain

• Arthritis limiting grazing or walking to feed

• Chronic infection

• Kidney or liver disease

• Inflammatory bowel disease

• Cancer

• Poor herd position or bullying

• Difficulty accessing feed or water

• Winter energy demands

• Malabsorption

• Heart disease

This matters because not every thin old horse can be fixed with a float.

In practice, if the dental exam does not fully explain the weight loss, your vet may recommend bloodwork, faecal egg count, PPID testing, diet analysis, pain assessment, and a broader senior health review.

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When Is This an Emergency?

Senior dental problems are often gradual, but some signs need urgent care.

Call your vet promptly if your horse has:

• Feed or saliva coming from the nostrils

• Repeated coughing or choking signs

• Refusal to eat

• Refusal to drink

• Severe drooling

• Facial swelling

• One-sided nasal discharge with bad smell

• Fever

• Depression or weakness

• Rapid weight loss

• Bleeding from the mouth

• A loose or broken tooth causing pain

• Sudden inability to chew

• Severe pain when the mouth is touched

• Signs of colic after eating

• Choke history with new swallowing difficulty

Choke is especially important. An older horse with poor teeth may swallow poorly chewed feed, hay, or dry pellets, increasing the risk of esophageal obstruction. If you suspect choke, remove feed and water and call your vet.

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What Should You Do Right Now?

If you are worried about your senior horse’s teeth, start with practical steps.

1. Watch a full meal.
   Do not just check whether the feed disappears. Watch how the horse chews, whether feed falls out, and whether they tire or pause.

2. Look for quids.
   Check the stall, paddock, feeder, and water trough for wads of partly chewed hay.

3. Check manure.
   Long hay fibres may suggest poor grinding.

4. Track body weight.
   Use a scale if available, or a weight tape and body condition scoring every 2 to 4 weeks.

5. Offer softer feed if chewing is difficult.
   Soaked senior feed, soaked hay pellets, or soaked hay cubes may help while you arrange a dental exam.

6. Do not keep increasing grain blindly.
   If the horse cannot chew forage, more dry concentrate may increase choke or digestive risk.

7. Book a veterinary dental exam.
   A senior horse with weight loss, quidding, bad breath, or feed dropping needs more than guesswork.

8. Call urgently for choke, swelling, fever, severe pain, or refusal to eat.

The immediate goal is to keep the horse eating safely while you find the cause.

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Common Mistakes Owners Make

Assuming weight loss is just old age
Age is not a diagnosis. Many older horses regain condition when dental pain, diet, PPID, parasites, or chronic pain are properly addressed.

Waiting until the horse is thin
Dental problems are easier to manage before the horse has lost major condition.

Feeding more dry grain instead of changing fibre form
A horse with poor teeth usually needs chewable fibre, not just more concentrate.

Skipping dental exams because the horse is retired
Retired horses still need to eat comfortably.

Assuming incisors tell the whole story
The cheek teeth do the grinding, and they are where many major senior problems hide.

Fearing extractions that would improve comfort
A painful diseased tooth is often worse for welfare than a missing tooth.

Using unsoaked pellets or cubes in a choke-prone horse
Older horses with poor chewing may need feeds soaked thoroughly.

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How To Prevent Senior Dental Problems From Becoming Crises

You cannot stop dental ageing, but you can reduce pain and catch problems earlier.

Helpful steps include:

• Schedule regular veterinary dental exams

• Increase exam frequency for horses with known dental disease

• Monitor weight and body condition monthly

• Watch for quidding or feed dropping

• Inspect manure for long fibres

• Feed according to chewing ability, not just age

• Introduce soaked feeds gradually

• Keep water easy to access

• Avoid large dry meals in horses with poor teeth

• Check for PPID and other senior diseases when weight changes

• Treat periodontal disease early

• Investigate bad breath or nasal discharge promptly

• Do not ignore painful incisors or EOTRH signs

Prevention in senior horses is not about making old teeth young again. It is about preserving comfort, chewing ability, and body condition for as long as possible.

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Will Your Senior Horse Be Okay?

Many senior horses do very well with the right dental and feeding plan.

The outlook is best when problems are caught early, the horse can still chew some forage, painful teeth are treated, and the diet is adjusted before major weight loss occurs.

Even horses with missing teeth can often live comfortably if their diet is changed appropriately. Some horses with severe EOTRH improve significantly after extraction once the painful teeth are removed. (Center for Equine Health)

The outlook becomes more guarded when:

• Weight loss is severe

• Multiple cheek teeth are missing

• The horse has repeated choke

• EOTRH is advanced

• Tooth root infection is present

• There is chronic sinus involvement

• Other senior diseases are also present

• The horse cannot safely maintain intake

The main message is this: old teeth are manageable, but ignored dental pain is not.

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FAQs

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Do horse teeth keep growing forever?

Not exactly. Horse teeth continue to erupt through life as they wear, but there is a finite reserve crown. In old horses, that reserve can become depleted, leaving less functional tooth for chewing. (MSD Veterinary Manual)

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Why is my old horse dropping hay?

Dropping hay, or quidding, often means the horse cannot grind forage properly. Common causes include worn teeth, missing teeth, sharp points, periodontal disease, or mouth pain. A veterinary dental exam is recommended.

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Can an old horse live without front teeth?

Yes, many horses can adapt well after incisor extraction, especially if their cheek teeth still work. They may need feeding adjustments, but many can graze using their lips and tongue. (Center for Equine Health)

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How often should an older horse have dental exams?

Most horses should have at least annual dental exams. Older horses, especially those with dental disease, missing teeth, EOTRH, weight loss, or quidding, may need exams every 6 months. (AAEP)

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Is EOTRH painful?

Yes, EOTRH can be very painful, especially in advanced cases. Signs may include gum inflammation, loose or fractured incisors, draining tracts, bad breath, reluctance to bite treats, and discomfort when incisors are touched. (MSD Veterinary Manual)

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Final Thoughts

“Long in the tooth” is more than an old saying. It is a reminder that a horse’s mouth changes dramatically over a lifetime.

A senior horse may look like they are eating, but still be failing to chew enough to maintain weight. They may seem fussy, but actually be protecting a painful tooth. They may avoid carrots not because they are picky, but because biting hurts.

The best senior dental care is proactive. Watch how your horse eats, monitor weight, check for quidding, schedule proper dental exams, and adjust the diet before weight loss becomes severe.

Old horses can live very well with imperfect teeth. They just need us to stop feeding them like young horses with perfect mouths.

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If you are unsure whether your senior horse’s weight loss, quidding, bad breath, or reluctance to eat is dental pain, ASK A VET™ can help you decide what to do next.