Can Horses Eat Acorns {Explained!}

Acorns can be good food for some animals, but this is not true for most livestock. Ruminants, such as goats, sheep and cattle are badly affected by eating acorns.

Horses, donkeys and other equines also experience negative effects when large amounts of acorns are consumed.

Acorns contain a significant amount of gallic and tannic acid, and both of these substances can do a great deal of damage to the kidneys and a horse’s gastrointestinal system.

In this article, we review the symptoms of acorn toxicity in horses and provide good advice on preventing it and treating it. Read on to learn more.

What Are The Symptoms Of Acorn Toxicity?

What Are The Symptoms Of Acorn Toxicity

If your horse has the opportunity to eat large amounts of acorns, you may see some or all of these symptoms:

  • Your horse may become constipated or may experience diarrhea.
  • Acorn toxicity can cause kidney damage leading to bloody urine.
  • Steady, ongoing consumption of acorns can lead to anorexia.
  • Your horse may develop a stomachache or colic.
  • Edema is an accumulation of fluid in the legs.
  • Your horse may exhibit signs of dehydration.

Are Oak Trees Safe At All?

horses eating acorns

Although we refer to this condition is acorn toxicity or acorn poisoning, it can actually be caused by ingestion of any part of an oak tree.

A well fed horse with plenty of pasture is unlikely to eat acorns, oak leaves, branches or bark; however, a hungry horse may start this bad habit and once it started it’s difficult or impossible to break.

Legend has it that horses who develop a taste for acorns and oak trees will become addicted and may eat these substances instead of eating grass, hay and normal horse feed.

Sometimes a well fed horse may pick up a few acorns accidentally while grazing. This is not a cause for concern. Even so, you should be vigilant if you have an oak tree in your pasture.

Watch your horse during his turnout time and take note if he seems to be lingering around the oak tree an unusual amount of time. Examine his manure for remnants of acorns.

How Can You Treat Acorn Poisoning?

Unfortunately, there is no known antidote for acorn toxicity. If you catch it right away, you may be able to administer activated charcoal in hopes of soaking up the toxins in your horse’s gut.

Once absorbed into the charcoal, the toxins can be carried out of the horses system in the manure.

If you missed the initial ingestion of the acorns AND your horse begins to show other symptoms, your vet will probably want to treat them individually.

For example, if your horse exhibits dehydration your vet will probably call for intravenous fluid therapy.

Staying well hydrated can prevent kidney failure. Intravenous fluid therapy also provides support for your horse’s circulatory system. This helps with shock prevention and assists your horse’s body in processing the toxins.

How Can You Prevent Acorn Toxicity?

The most obvious thing to do is avoid having oak trees in your pasture or near it. If this is not a possibility, you need to manage your oak trees carefully.

Rake up acorns as soon as they fall, and be sure to pick up fallen branches following windstorms.

Feed your horses well and keep them active and engaged to prevent boredom and the bad habit of chewing on tree bark.

Horse Eating Tree Bark

Frequently Asked Questions

1. Are acorns the only nuts horses shouldn’t eat?

Nuts are just not a natural part of a horse’s diet, and you should take steps to prevent your horse eating any sort of nuts. Especially harmful are:
– Sago Palm Nuts contain very high levels of a poisonous substance known as cycasin. Ingesting the nuts or any part of this plant can cause ataxia, depression and diarrhea.
– Black Walnuts and their hulls can cause digestive distress if ingested. Additionally, bedding made of black walnut wood chips is toxic to horses and should not be used.
– Buckeyes or Horse Chestnuts can cause anxiety, diarrhea and even convulsions.
Take care to remove the trees that produce these nuts from your pasture. If your horse does ingest any of these, consult your vet. Luckily, horses that are well-fed and well-cared for don’t typically eat these nuts or the plants they come from.

2. If I am eating pistachio nuts, can I share them with my horse?

Pistachio nuts are very toxic to horses because they contain the oxidizing toxins:
– Tannic acid
– Gallic acid
– Pyrogallol
These substances negatively impact equines more than they do any other animal. Pistachio poisoning causes ataxia, colic, lethargy, loss of appetite, oddly colored urine and death. Do not allow your horse to eat pistachios.

3. Are sunflower seeds nuts? Are they safe for horses?

Sunflower seeds are not nuts, and they are safe for horses (both shelled and unshelled). In fact, adding a small amount of sunflower seeds to your horses’ feed can help improve coat condition. Black oil sunflower seeds are typically available in large amounts as bird feed. The black oil variety has a higher amount of protein and fat and a lower amount of fiber than the striped variety.

4. Can horses eat pumpkin seeds?

Yes, pumpkin seeds and flesh are safe for horses to eat. You can dry the seeds or feed them fresh after you clean a pumpkin to make pie or a jack o’lantern or some such. Pumpkin has less starch and sugar than apples and carrots, and it delivers many health benefits.

5. Do pumpkin seeds kill intestinal worms in horses?

Feeding pumpkin seeds (and other vine crop seeds) may very well help keep intestinal worms under control. The seeds of pumpkins, squash, cucumbers and the like contain cucurbitacin, which is a natural deworming compound.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Horses & Foals

6022 S Drexel Ave
Chicago, IL 60637

Amazon Disclaimer

Horses & Foals is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to


Horses & Foals do not intend to provide veterinary advice. We try to help users better understand their horses; however, the content on this blog is not a substitute for veterinary guidance. For more information, please read our PRIVACY POLICY.