Why Do Horses Eat Manure? Vet Approved Answer

When is it normal for horses to eat manure and does it benefit them?
| Updated: January 12, 2024
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Reviewed by: Dr. Jerry Ayaebi
Thoroughbred horses grazing in a pasture at sunset

Imagine the perfect morning. You’ve just grabbed your steaming cup of coffee and walked out on your back porch to sit and gaze out over the pasture. Watching your majestic horse is the highlight of waking up, after all. But today, you’re startled by an unbelievable sight. “My Horse is eating poop!”

It’s a shocking sight, to be sure, but not a totally uncommon one. Surely, you’re wondering why on earth he would do that? Is it normal? Is it bad?

There’s actually a term for it called coprophagy. Literally meaning “the eating of feces or dung.” Fortunately, horses eating manure is a normal part of development when they’re young. Even as adults, it can be safe and beneficial, although gross to us. But let’s take a look at why horses eat manure and what the risks and benefits are.

What is Coprophagy?

Coprophagy is the scientific term for “eating feces.” It’s a common behavior in many animals, such as rabbits, rodents, dogs, pigs, and elephants. It actually serves different purposes, such as obtaining nutrients, establishing gut flora, marking territory, or hiding from predators.

In horses, eating horse poop is mostly seen in foals and young horses, but adult horses sometimes do it too. Coprophagy in horses is not usually a serious problem, but it may indicate some underlying issues that need to be addressed.

Why Do Foals Eat Manure?

A common question that horse owners ask is: Why do foals eat manure? The answer is an easy one: they eat manure to help their digestive system develop and function properly.

To add to this, when foals practice coprophagy, it enhances their immune system. This is because when ingesting manure, they might also ingest some parasite eggs, which triggers the immune system and, in turn, builds a stronger immunity.

Foals are born with a sterile gut, which means there are no bacteria in their intestines. Normal intestinal bacteria are essential for breaking down and absorbing the fiber and nutrients from food, in this case, grass or hay. Without these bacteria, foals wouldn’t be able to digest their food, and they’d suffer from malnutrition and disease.

To seed their gut with these beneficial bacteria, foals start eating manure when they are about two to three weeks old. Don’t worry; this is a normal and natural stage of a horse’s development. By eating manure, foals ingest the beneficial bacteria from their dam’s feces and transfer them to their own gut. This establishes and helps maintain a healthy gut microbiome that can enhance their immunity and prevent infections.

Some researchers believe that a pheromone exists in a mare’s feces that encourages foals to eat it, but so far, there is no evidence to support it. 

Foals do get some vitamins and minerals from their dam’s manure that they may not get from milk or solid feed. For example, foals get vitamin B12 from manure, which is important for their nervous system and blood cell formation. Manure also typically contains iron, which is important for oxygen transport and energy production.

Usually, foals stop eating manure around 12-19 weeks old. At this point, their digestive system is fully developed, and they can graze on grass or hay. Occasionally, some foals may continue to eat manure until they are weaned or even older.

Why Do Adult Horses Eat Manure?

While foals eat manure for a clear reason, adult horses eat manure for more complex and varied reasons. There are several common reasons why horses eat manure, like:

  • Nutritional deficiency: Horses will eat manure to supplement their diet with nutrients that they are lacking, such as fiber, protein, vitamin B12, or minerals. This can happen if horses are fed a diet that is low in quality or quantity of forage or if they have poor absorption or metabolism of nutrients due to age or disease. Studies have shown that manure-eating was eliminated in horses that had a readily available food source.
  • Boredom: Horses sometimes eat manure to relieve boredom or stress when they have limited access to forage or stimulation, like when confined to a stall. They are naturally curious and social animals that like to explore and interact with their environment and herd mates. If they don’t have enough opportunities to do so, they may resort to many odd behaviors.
  • Habit: A horse might be eating manure because they learned to do it from their dam or other horses when they were young. Horses are very imitative and learn by observing and copying other horses.
  • Taste: Pretty much how it sounds. Some horses might like the taste of manure.
  • Equine Motor Nueron Disease: Horses with Equine Motor Nueron Disease (EMND) have been known to eat manure. 

Is Eating Manure Harmful for Horses?

Eating manure is usually harmless for horses as long as it is not excessive or compulsive. In fact, eating manure can have some benefits for horses, such as:

  • Providing extra fiber and nutrients that can improve digestion and health.
  • Helping to establish, or re-establish, and maintain a healthy gut microbiome.

However, eating manure can also have some risks for horses, such as:

  • Transmitting parasites or diseases that can cause diarrhea, weight loss, anemia, or colic. Infected manure from horses or other animals, such as dogs, cats, or wildlife, can quickly pass a nasty bug along. Horses should be dewormed regularly and kept away from contaminated manure sources.
  • Causing dental problems or choking by ingesting foreign objects that may be present, such as stones, sticks, or plastic. Horses should be checked for any signs of oral injury or obstruction and given access to clean water at all times.
  • Interfering with the normal feeding behavior and appetite. Horses should be fed enough good quality hay or pasture to meet their nutritional needs and satisfy their grazing instinct.

How to Prevent or Reduce Manure-Eating in Horses?

If your horse is eating manure, you should first try to identify the reason why they are doing so and address it accordingly. If you are concerned about it or they are showing other changes in behavior, you should consult your veterinarian. If they are otherwise acting normally, you can try to:

  • Improve the diet: Make sure your horse is getting enough roughage in their diet, preferably from fresh grass or hay. Roughage is the main source of fiber and nutrients for horses and helps to keep their digestive system healthy and functioning properly. Horses should have access to forage all day long and be able to graze or chew for at least 16 hours a day. If your horse is not getting enough roughage, you can supplement their diet with a prebiotic or probiotic product that can help improve their gut health and digestion. You can also add a vitamin and mineral supplement to their diet if they are deficient in any essential nutrients.
  • Provide enrichment: Provide your horse with more opportunities to exercise, play, and socialize with other horses. Horses need physical and mental stimulation to keep them happy and healthy. You can enrich your horse’s environment by giving them toys, puzzles, treats, or other objects that they can interact with. You can also increase their activity level by riding, lunging, or free schooling them regularly. You can also allow your horse to spend more time with other horses in a pasture or paddock where they can graze, groom, and communicate with each other.
  • Break the habit: If your horse is eating manure out of habit, you can try to discourage them from doing so by using positive or negative reinforcement. Positive reinforcement involves rewarding your horse with praise, treats, or attention when they stop eating manure or choose another behavior instead. Negative reinforcement involves applying an unpleasant stimulus, such as a spray of water, a loud noise, or a mild electric shock when your horse starts eating manure. You should always be consistent and timely with your reinforcement and avoid being harsh or abusive to your horse.

Article Sources

BuzzPetz uses high-quality sources like medical journals, peer-reviewed studies, and statements from veterinarians to support the facts in our articles.
Chase Roseberry Author Image
Chase Roseberry

Chase’s life has been a remarkable journey into the world of animals. From his time spent working with an equine Veterinarian, raising exotic snakes, and live coral aquaculture, his diverse background fuels his passion for the animal kingdom.

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