Is My Horse Overweight? Obesity, EMS, and Laminitis Risk

By Dr Duncan Houston

A round horse can look healthy at first glance.

Owners often describe them as “well covered,” “chunky,” “good doers,” or “pleasantly plump.” The problem is that extra fat in horses is not just cosmetic. It can be linked to insulin dysregulation, equine metabolic syndrome, laminitis, joint strain, poor fitness, heat intolerance, and long-term hoof damage.

The difficult part is that many overweight horses do not look sick until their feet hurt.

That is why obesity management is not about making horses look prettier. It is about preventing pain, especially laminitis.

Quick Answer

If your horse is overweight, cresty-necked, has fat pads, gains weight easily, or becomes footsore after pasture access, they may be at risk of equine metabolic syndrome and laminitis. EMS is associated with abnormal insulin regulation, increased fat deposition, difficulty losing weight, and a high risk of laminitis. (Center for Equine Health)

The safest plan is controlled weight loss using weighed forage, low-sugar and low-starch feeding, restricted pasture, regular body condition scoring, insulin testing when indicated, farrier care, and exercise only if the horse is sound.

Why Horses Become Overweight

Many horses, ponies, and donkeys are efficient survivors.

Historically, that was useful. A horse that could maintain condition on sparse forage had a survival advantage. In modern management, with improved pasture, hay, hard feed, supplements, treats, and limited work, that same efficiency can become a serious health problem.

Common causes of obesity include:

• Unrestricted pasture

• High-calorie hay

• Grain or sweet feed the horse does not need

• Feeding by scoop or flake instead of weight

• Too many treats

• Low workload

• Limited turnout

• Pain or lameness reducing movement

• PPID or insulin dysregulation

• Owners underestimating body condition

In practice, the most dangerous phrase is often: “But he barely eats anything.”

Many easy keepers can gain weight on forage alone, especially when pasture is rich or hay is more calorie-dense than expected.

What Is Equine Metabolic Syndrome?

Equine metabolic syndrome, or EMS, is a metabolic condition associated with insulin dysregulation, increased fat deposition, and reduced ability to lose weight. Affected horses often produce excessive insulin after eating certain carbohydrates, especially sugars and starches. (Center for Equine Health)

EMS commonly affects easy keepers, ponies, donkeys, Arabians, mustangs, and other thrifty types, but any horse can be affected.

Common EMS warning signs include:

• Cresty neck

• Fat pads around the tailhead, shoulders, sheath, udder, or ribs

• Easy weight gain

• Difficulty losing weight

• Recurrent laminitis

• Foot soreness after pasture access

• Hoof rings

• Abnormal insulin testing

• Strong reaction to grass, grain, or sweet feeds

Not every overweight horse has confirmed EMS. Not every EMS horse is dramatically obese. That is why testing matters.

Why Obesity Increases Laminitis Risk

The most important obesity-related concern is laminitis.

Laminitis occurs when the sensitive laminae inside the hoof become damaged and inflamed. In severe cases, the coffin bone can rotate or sink, causing long-term pain, structural damage, and sometimes euthanasia.

Endocrine-related laminitis is now one of the most important forms of laminitis in horses. Merck Veterinary Manual notes that endocrine dysfunction is probably the most common underlying cause of laminitis today, with hyperinsulinaemia considered a major predisposing factor. (Merck Veterinary Manual)

That means the real danger is not just body fat itself.

The real danger is what that body fat may signal: abnormal insulin control, high laminitis risk, and hooves living too close to the edge.

How To Tell if Your Horse Is Overweight

Do not judge by the belly alone.

A horse can have a big belly from forage fill but poor muscle. Another horse can look “solid” but be carrying dangerous fat deposits around the neck, shoulders, tailhead, and sheath or udder.

Use body condition scoring.

The common Henneke body condition scale runs from 1 to 9:

University of Minnesota Extension notes that scores of 4 to 6 are generally considered ideal, while 7 to 9 are overweight to obese. (University of Minnesota Extension)

Also check the neck crest. A cresty neck score of 3 or higher is associated with overweight status and metabolic risk. (University of Minnesota Extension)

Areas to assess include:

• Ribs

• Neck crest

• Withers

• Behind the shoulder

• Back and loin

• Tailhead

• Fat pads around the sheath, udder, shoulders, and rump

If you cannot easily feel the ribs with light pressure, the horse may be carrying too much fat.

“Pleasantly Plump” vs Clinically Overweight

This is where owners often get caught.

A horse can look shiny, happy, and well fed, but still be clinically overweight. Obesity does not always look dramatic. In some horses, the first obvious problem is laminitis.

More reassuring

This is usually less concerning if your horse:

• Has a body condition score around 4 to 6 out of 9

• Has no cresty neck

• Has no abnormal fat pads

• Moves freely

• Has normal digital pulses

• Has no laminitis history

• Has no foot soreness after pasture

• Maintains weight with a measured diet

More concerning

This becomes more concerning if your horse:

• Has a body condition score of 7 or higher

• Has a firm neck crest

• Has fat pads

• Gains weight easily

• Is hard to slim down

• Has limited exercise

• Has unrestricted pasture access

• Gets grain or sweet feed despite low workload

• Has not had insulin testing

High risk

This is high risk if your horse:

• Has confirmed insulin dysregulation

• Has EMS

• Has PPID with high insulin

• Has previous laminitis

• Becomes pottery after pasture

• Has heat in the hooves

• Has strong digital pulses

• Has hoof rings suggesting previous laminitis

• Is overweight and still eating pasture or high-NSC feed

Critical

This is urgent if your horse:

• Is suddenly lame

• Is reluctant to walk

• Rocks back onto the hindlimbs

• Has heat in the feet

• Has strong or bounding digital pulses

• Lies down more than normal

• Refuses to turn

• Shows severe pain

• Has known EMS or PPID and any new foot soreness

That is not a weight-loss issue for later. That is possible laminitis and needs veterinary care.

When Is This an Emergency?

Call your vet urgently if your horse has signs of laminitis.

Red flags include:

• Sudden foot soreness

• A short, pottery gait

• Reluctance to walk on hard ground

• Reluctance to turn

• Heat in the hooves

• Strong digital pulses

• Rocking weight back onto the hindlimbs

• Repeated lying down

• Refusing to pick up one foot because the others hurt

• Sweating, depression, or obvious pain

Do not exercise a horse with suspected laminitis. Do not turn them out on grass to “loosen up.” Do not wait a few days to see whether it settles.

Early veterinary care, pain relief, diet control, foot support, and radiographs can change the outcome.

What Else Can Look Like Obesity or EMS?

Not every overweight-looking horse has EMS, and not every horse with weight problems has the same cause.

Important rule-outs include:

• EMS

• PPID

• Insulin dysregulation

• Excess pasture intake

• High-calorie hay

• Overfeeding grain or concentrates

• Low workload

• Pain limiting movement

• Arthritis

• Chronic lameness

• Pregnancy

• Poor topline with a hay belly

• Regional fat deposits without confirmed insulin dysregulation

• Hidden treats or multiple people feeding

• Inaccurate weight estimate

• Over-rugging or seasonal management changes

Older horses may also have PPID and insulin dysregulation at the same time. That combination can make laminitis prevention more complicated.

What Should You Do Next?

1. Stop Guessing and Measure

Start with facts.

Record:

• Body condition score

• Cresty neck score

• Weight using a scale, weigh tape, or body measurements

• Photos from the side, front, and behind

• Current hay amount by weight

• Current pasture access

• Current feed and supplements

• Exercise level

• Any history of foot soreness or laminitis

Recheck body condition and weight trends every 2 to 4 weeks.

2. Remove Unnecessary Grain and Sweet Feed

Most overweight horses do not need grain.

Remove or avoid:

• Sweet feed

• Grain mixes

• Molasses

• High-starch concentrates

• Conditioning feeds

• Large carrot or apple treats

• Sugary commercial treats

• Calorie-heavy supplements without a clear reason

If the horse needs vitamins and minerals, use a low-calorie ration balancer or mineral supplement instead of a calorie-dense feed.

Michigan State University notes that EMS management commonly involves reducing calorie intake, restricting dietary sugar, increasing exercise, and often eliminating grain and pasture during the initial weight-loss phase. (cvm.msu.edu)

3. Weigh the Hay

Hay flakes are not accurate.

If your horse needs weight loss, forage should be weighed. For many overweight EMS horses, UC Davis recommends starting around 1.5% of ideal body weight in forage per day, with possible reduction to 1.25% after 30 days if needed, under veterinary guidance. (Center for Equine Health)

For example, if the horse’s ideal weight is 500 kg:

• 1.5% ideal body weight = 7.5 kg forage per day

• 1.25% ideal body weight = 6.25 kg forage per day

Do not crash diet horses, ponies, or donkeys. Sudden severe restriction can create other metabolic problems.

4. Test the Hay if EMS or Laminitis Risk Is Present

Hay can look safe and still be too high in sugar and starch for a metabolic horse.

For horses with EMS, UC Davis recommends hay ideally below 10% non-structural carbohydrates, or NSC, on a dry matter basis. (Center for Equine Health)

If hay is too high in NSC, options may include:

• Changing hay source

• Soaking hay where appropriate

• Using a tested lower-NSC hay

• Using slow feeders to extend eating time

• Avoiding pasture or limiting it strictly

Soaking may reduce some sugars, but it is variable. Testing is more reliable than guessing.

5. Control Pasture

Pasture is often the biggest hidden calorie and sugar source.

For EMS horses, pasture may need to be reduced or eliminated, especially during weight loss or after laminitis. UC Davis lists reduced or eliminated pasture access as a core part of EMS management. (Center for Equine Health)

Options include:

• Dry lot turnout

• Track system

• Grazing muzzle

• Strip grazing

• Very limited supervised turnout

• Avoidance of lush spring and autumn pasture

• Avoidance of frosty or stressed grass

• Tested hay instead of grass

Short turnout does not always mean low intake. Some horses eat very quickly when access is restricted.

Horses are remarkably talented at speed-running poor decisions.

6. Exercise Only if the Horse Is Sound

Exercise is very useful for weight loss and insulin sensitivity, but only if the horse is not actively laminitic.

Merck Veterinary Manual notes that once laminitis has resolved, exercise can improve insulin sensitivity by building muscle and reducing fat, but exercise should not be increased if the horse becomes lame. (Merck Veterinary Manual)

If the horse is sound, start gradually.

A basic plan may include:

• Daily hand-walking

• Increased turnout in a dry lot or track

• Light ridden work if appropriate

• Walking hills when sound and conditioned

• Gradual increase in duration before intensity

If the horse is footsore, the feet come first.

7. Ask Your Vet About Insulin and PPID Testing

Testing is important if your horse:

• Has a cresty neck

• Has abnormal fat pads

• Is hard to slim down

• Has had laminitis

• Becomes sore after pasture

• Is older and has coat changes

• Drinks and urinates more than normal

• Has recurrent infections

• Has hoof rings or chronic foot soreness

EMS is diagnosed by documenting insulin dysregulation, not by body shape alone. Merck notes that obesity and a cresty neck do not automatically confirm EMS, and absence of obesity does not rule out insulin dysregulation. (Merck Veterinary Manual)

Common Mistakes Owners Make

Calling Obesity “Condition”

A horse can be shiny, round, and still dangerously overweight.

Feeding Less Grain but Ignoring Grass

For many easy keepers, pasture is the real problem.

Not Weighing Hay

If hay is not weighed, the diet is still guesswork.

Starving the Horse

Weight loss should be controlled. Severe restriction can be dangerous, especially in ponies, donkeys, and very obese horses.

Exercising a Footsore Horse

Exercise helps EMS only when the horse is sound. Active laminitis needs veterinary treatment first.

Using Supplements Instead of Fixing the Diet

No supplement can outwork unrestricted pasture, high-NSC hay, and excess calories.

Ignoring the Neck Crest

A firm crest is a metabolic warning sign, not just a cute breed feature.

How To Prevent Obesity, EMS, and Laminitis

Prevention is easier than treating laminitis.

Focus on:

• Body condition scoring every 2 to 4 weeks

• Monitoring the neck crest

• Tracking weight trends

• Weighing hay

• Testing hay for high-risk horses

• Restricting pasture when needed

• Removing unnecessary grain

• Using a ration balancer instead of calorie-heavy feed

• Exercising regularly when sound

• Keeping farrier visits consistent

• Checking digital pulses in high-risk horses

• Testing insulin and ACTH when signs suggest EMS or PPID

• Adjusting the plan before spring and autumn pasture growth

• Avoiding sudden feed changes

The best obesity plan is boring, measured, and consistent.

Very unglamorous. Very effective.

Will My Horse Be Okay?

Many overweight horses do very well when the problem is recognised before laminitis occurs.

If your horse is still sound, bright, and only mildly overweight, controlled forage, pasture restriction, exercise, and monitoring can make a big difference over weeks to months.

If your horse already has laminitis, EMS, insulin dysregulation, or PPID, the plan needs to be stricter and veterinary-guided. The outcome depends on how early the problem is caught, how severe the hoof involvement is, whether insulin can be controlled, and whether weight loss is achieved safely.

The key is early action.

A cresty neck, fat pads, and mild pasture-related foot soreness are not cosmetic details. They are warnings.

FAQs

How do I know if my horse is too fat?

Use body condition scoring and feel the ribs, neck, shoulders, back, and tailhead. If you cannot easily feel the ribs with light pressure, or your horse has a firm cresty neck or fat pads, they may be overweight.

Does every overweight horse have EMS?

No. Obesity increases risk, but EMS requires insulin dysregulation. Testing helps confirm whether your horse has a metabolic problem.

Can an overweight horse still eat hay?

Yes. Horses still need forage. The goal is to feed the right amount of appropriate forage, usually weighed, and to choose lower-NSC hay when EMS or laminitis risk is present.

Should I stop all pasture for an EMS horse?

Some EMS horses need pasture eliminated, especially during weight loss or after laminitis. Others may later tolerate limited muzzled turnout. The decision depends on insulin status, body condition, laminitis history, and veterinary advice.

Can I exercise an overweight horse with laminitis?

Not during active laminitis. A footsore horse needs veterinary care, pain relief, diet control, and hoof support first. Exercise can be added only when the horse is stable and cleared by your vet.

Final Thoughts

A “pleasantly plump” horse is not always healthy.

Obesity in horses can be the visible sign of a deeper metabolic problem, especially when there is a cresty neck, fat pads, pasture sensitivity, or foot soreness. The biggest concern is laminitis, because once the feet are damaged, everything becomes harder, slower, more painful, and more expensive.

The safest approach is simple but strict: measure body condition, weigh the hay, control pasture, remove unnecessary calories, test insulin when risk signs appear, exercise only when sound, and involve your vet before the hooves are in trouble.

Do not wait for founder to prove the horse was overweight.

Act when the warning signs are still small.

If you are unsure whether your horse is overweight, at risk of EMS, or showing early laminitis signs, ASK A VET™ can help you work through the body condition, diet, pasture access, and warning signs before a weight problem becomes a hoof crisis.