Why Is My Horse Not Eating? Causes and When to Worry

Name: Why Is My Horse Not Eating? Causes and When to Worry
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-02

A horse that stops eating is telling you something is wrong. In most cases, a horse not eating points to pain, illness, stress, or a management problem instead of simple pickiness. Because horses are designed to eat almost constantly, even a short pause in intake can matter.

This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

A horse that refuses all feed for more than 12 to 24 hours, or shows signs of pain, needs a veterinarian today.
Pain is the most common serious cause, and gastrointestinal obstruction (a blockage) is a leading concern because it can damage the intestine [1].
If your horse is eating hay but refusing grain, or the reverse, that pattern gives your vet useful clues.
Offer fresh green grass, which many sick horses will eat even when they refuse other feeds [2].
Never force feed, and never give medication without veterinary direction.

What "Not Eating" Actually Looks Like

Horses are trickle feeders. They graze or nibble hay for most of the day and night, with short rest periods. Normal eating behavior is steady and fairly easy to recognize once you know your horse's routine. Automated monitoring systems can identify eating behavior in stalled horses with high accuracy, which is one reason barn cameras and smart feeders are becoming more common [3].

A horse that is "not eating" may show one of several patterns:

Refusing everything, including hay, grain, and treats.
Eating hay but leaving grain, or eating grain but ignoring hay.
Picking at food, dropping mouthfuls, or quitting after a few bites.
Standing away from the feeder, lying down more than usual, or acting dull.
Eating slowly, which can be easy to miss in a busy barn.

Knowing which pattern you are seeing helps your veterinarian narrow the list quickly.

Why Is My Horse Not Eating? Main Causes

Many conditions cause a horse to go off feed. Some are painful and urgent. Others are mild or management related. The table below groups the most common causes and what typically points to each one.

Cause	Typical clues	How urgent
Gastrointestinal obstruction (blockage)	Pawing, rolling, flank watching, no manure, sweating	Emergency now [1]
Feed impaction or coarse feed	Reduced water intake, recent diet change, mild colic signs	Same day [1]
Dental problems	Quidding (dropping wads of hay), weight loss, slow eating	Routine to same day
Pain anywhere (lameness, ulcers, injury)	Stiff movement, grumpy attitude, poor appetite	Same day
Stress or herd change	New barn, new horse, travel, weather shift	Monitor closely
Fever or infection	Dull attitude, increased breathing, warm to touch	Same day
Liver disease or rare tumors	Poor weight gain, inappetence, vague signs	Same day [4]
Unpalatable or spoiled feed	Sudden refusal, moldy or musty smell	Management fix
Rapid eating and choke	Coughing, feed and saliva from the nose	Emergency now [5]

Obstruction and Colic

Intestinal obstructions are common in horses and can occur anywhere in the digestive tract [1]. They cause sharp, severe pain and can stop food from moving through the gut. In some cases they also impair blood flow or damage intestinal tissue [1].

Obstructions can be mechanical (a physical blockage) or functional (the gut simply stops moving) [1]. Feed impactions, parasite problems, bad teeth, intestinal inflammation, electrolyte imbalances, and changes in diet, activity, medication, or sudden stress can all play a role [1]. Coarse feed, low water intake, and eating foreign objects are other common factors [1].

This is the cause owners worry about most, and rightly so. A horse with a blockage often stops eating and shows pain within hours.

Choke and Rapid Eating

Choke in horses is an esophageal obstruction, not a throat problem like in people. Bolting feed quickly raises the risk [5]. One study found that horses ate concentrate more slowly from a shallow trough than from a hanging feeder or a pan on the ground, and that feeding from the ground produced the most wasted feed [5]. If your horse bolts grain, changing the feeder style is a simple, evidence-based step.

Dental and Mouth Problems

A horse with a painful tooth, sharp enamel point, or mouth ulcer may want to eat but cannot chew comfortably. Watch for quidding, which is dropping partially chewed balls of hay. This often shows up as a horse eating hay but leaving grain, or the opposite, depending on which texture hurts.

Pain and Illness Elsewhere

Horses are stoic. A lame horse, a horse with gastric ulcers, or one with a low-grade infection may simply eat less. Any source of chronic pain can suppress appetite.

Liver and Other Internal Disease

Liver problems and, rarely, liver tumors can cause vague signs like poor weight gain and inappetence before anything else shows up [4]. These cases are hard to catch early because the signs are so nonspecific [4]. Unexplained weight loss with a poor appetite always deserves a veterinary workup.

Stress, Feed Changes, and Palatability

Horses are sensitive to smell and taste. They use smell first to decide whether feed is safe to eat, and horses with more past experience of a plant's smell and taste recognize it faster in the future [6]. That means a sudden feed change, a new hay supplier, or a strange smell in the bin can put a horse off its feed.

Stress from travel, a new herdmate, or a change in routine can also reduce intake for a day or two.

The Weight Loss Puzzle

If your horse is eating well but not gaining weight, appetite is not the problem. That pattern points toward poor digestion, parasites, dental issues, or underlying disease. It is a different workup than a horse that has stopped eating, so describe the difference clearly to your vet.

Red Flags That Make It an Emergency

Call your veterinarian immediately, day or night, if you see any of these:

Rolling, thrashing, or repeatedly getting up and down.
Pawing at the ground, kicking at the belly, or flank watching.
No manure for 12 hours or more.
A distended or tight belly.
Feed or saliva draining from the nose, or coughing while eating.
Profuse sweating without exercise or hot weather.
A temperature above the normal adult range (your vet can tell you your horse's baseline).
Refusing all food and water for more than 12 to 24 hours.

These signs suggest obstruction, choke, or another serious problem that will not resolve on its own [1][5].

Safe Things You Can Do While You Wait

While you wait for your veterinarian, keep it simple and safe.

Remove grain and concentrates. Offer only small amounts of hay or fresh grass.
Offer fresh green grass. Many horses will eat grass even when they refuse other feeds [2].
Try small amounts of a novel, appropriate feed and let the horse choose what it finds palatable [2].
Add flavor. Molasses, applesauce, carrots, or peppermint may increase acceptance in a horse that is not eating [2].
Keep fresh, clean water available at all times. Low water intake contributes to impactions [1].
Walk your horse gently if your vet advises it, but do not force movement during severe pain.
Do not give pain medication, banamine, or any drug unless your vet tells you to. Masking pain can hide critical signs.
Do not force feed or use a stomach tube on your own.

If your horse is eating hay but refusing grain, note that. If it is the reverse, note that too. Your vet will use those details.

If you also care for other species, the same "off feed" logic applies to them. You can read more about appetite loss in dogs in Why Is My Dog Not Eating? and Dog Not Eating: When to Worry and What to Do, and about cats in Cat Not Eating? When to Worry and What to Do.

What Your Veterinarian Will Check and Test

Your vet will start with a full physical exam, including heart rate, respiratory rate, temperature, gut sounds, and a careful check of the mouth and teeth. They will ask about recent diet changes, water intake, manure output, and stress events, because all of these play a role in functional obstructions [1].

Depending on findings, they may recommend:

A rectal exam to feel for impactions or distension.
A nasogastric tube to check for reflux and to relieve pressure.
Bloodwork to look at electrolytes, liver values, and signs of infection or inflammation.
Ultrasound of the abdomen or liver.
Dental examination with a speculum.

If liver disease is suspected, imaging and sometimes biopsy help confirm it, though these cases can be hard to diagnose early [4].

Treatment depends on the cause. Your vet will calculate any medication dose from your horse's weight and health status.

Prevention and Daily Monitoring

Most appetite problems are easier to prevent than to treat.

Feed on a schedule and change diets gradually over 7 to 10 days.
Use a shallow trough for concentrates if your horse bolts its feed, since intake is slower from a trough than from a hanging feeder or ground pan [5].
Provide constant access to clean water, and check buckets in freezing weather.
Have teeth checked at least once a year, more often for seniors.
Keep a deworming plan your vet approves.
Watch manure output daily. It is one of the best early warning signs.
Learn your horse's normal eating speed and habits so changes stand out.
Consider a stall camera or smart feeder, since eating behavior is a reliable health indicator and can now be tracked automatically [3].

If your horse is eating but still losing weight, that is a separate problem. Bring it up at your next visit instead of waiting for appetite to drop.

Limitations and When to Contact a Veterinarian

No article can tell you what is wrong with your individual horse. Only a veterinarian who examines your horse can do that.

Call your veterinarian the same day if your horse:

Refuses all feed for 12 to 24 hours.
Eats hay but refuses grain, or the reverse, for more than a day.
Shows mild colic signs that come and go.
Has a fever, dull attitude, or reduced manure.
Has unexplained weight loss despite eating.

Call immediately, at any hour, if your horse:

Is rolling, thrashing, or in obvious severe pain.
Has feed or saliva coming from the nose.
Has no manure for 12 hours or more.
Has a distended belly or is sweating without cause.

Schedule a routine visit for slow eating, quidding, gradual weight loss, or a horse that has always been a picky eater but is otherwise well.

Frequently Asked Questions

How long can a horse go without eating?

A healthy adult horse should not go more than about 12 to 24 hours without eating before you call a veterinarian. Horses are designed to eat almost continuously, so a full day of refusal is a serious sign. If your horse also stops drinking or passing manure, treat it as an emergency.

Why is my horse eating hay but not grain?

This pattern often points to pain, stress, or an unpalatable concentrate instead of a total loss of appetite. Some horses develop mouth pain that makes chewing hard grain uncomfortable while soft hay is still manageable. It can also mean the grain is spoiled or was recently changed. Have your vet check the mouth and teeth if it lasts more than a day.

Can stress cause a horse to stop eating?

Yes, stress from travel, a new barn, a new herdmate, or a routine change can reduce appetite for a day or two. Sudden stress is also listed as a factor in functional obstructions, so it is not always harmless [1]. If your horse is otherwise bright and drinking well, monitor closely. If it lasts longer than 48 hours or comes with pain signs, call your vet.

Should I try to tempt my horse with treats or molasses?

Yes, small amounts of palatable additions can help. Molasses, applesauce, carrots, and peppermint may increase feed acceptance in a horse that is not eating [2]. Fresh green grass is often accepted when other feeds are refused [2]. Keep portions small and avoid sweet feed in large amounts, since it should be used sparingly in most cases [2].

What does it mean if my horse is not gaining weight but eating well?

This usually means the problem is digestion, parasites, dental function, or underlying disease instead of appetite. Liver disease and rare liver tumors can cause poor weight gain and inappetence with very vague early signs [4]. Ask your veterinarian for a full workup, including bloodwork and a dental exam, instead of assuming your horse just needs more feed.

References

Gastrointestinal Obstruction (Blockages) in Horses - Horse Owners. Merck Veterinary Manual.
Feeding the Sick Horse and Other Equids - Management and Nutrition. Merck Veterinary Manual.
Sleeping and Eating Behavior Recognition of Horses Based on an Improved SlowFast Network. Sensors (Basel, Switzerland), 2024.
Two cases of primary hepatic neoplasia in young horses: Diagnostic challenges and clinical implications. Journal of equine veterinary science, 2026.
Effect of feeder style on intake rate of equine concentrates. Journal of equine veterinary science, 2026.
Horse Olfactory Exploration of Various Plants with Regard to Smell and Taste Familiarity. Animals : an open access journal from MDPI, 2026.