are acorns poisonous to horses

Can Horses Eat Acorns

Are Acorns Poisonous To Horses?

As horse owners, one of our biggest fears is that our equine companions will eat something dangerous out in the pasture – especially if they have a tendency to be serious munchers.

With oak trees being a common feature of the British countryside, there’s a chance your horse may pick up a few acorns accidentally while grazing. But is this good or bad?

In small amounts, acorns aren’t a big deal for horses, but if they eat a bunch, it could lead to serious health issues.

Read on to learn about the potential risks of acorns for your horses and how you can keep them safe and healthy.

Horse in front of an oak tree

Can Horses Eat Acorns?

If you have an oak tree in your paddock, chances are there are a few acorns around where your horse grazes. When autumn arrives and the acorns start dropping, you might catch your horse crunching down on a few. Some horses even develop a peculiar fondness for the taste. But is it safe for your horse to eat?

The unfortunate truth is: oak acorns and horses don’t mix, no matter how delicious they may find them. While there’s some talk about the potential benefits of this botanical nut for horses, it’s not worth the risk of feeding it to them or allowing them to eat it.

A horse eating a couple of oak acorns won’t generally pose a problem, especially if they have a well-balanced diet with plenty of high-fibre hay or grass. However, this isn’t always the case, as some horses can have different reactions and tolerances to acorns.

Certain horses are more prone to acorn poisoning, and even a tiny amount can make them ill. It’s impossible to predict how your horse will react or determine a “safe” amount.

A horse consuming a large number of acorns can result in acorn toxicity due to the presence of tannic acid (tannins). Tannic acid can be found in immature green acorns and other parts of oak trees such as oak leaves. These tannins can interfere with the horse’s nutrient absorption and can potentially lead to gut and kidney issues.

Green acorn on a tree

Green acorns are full of tannic acid which is particularly bad for horses

Symptoms of Acorn Poisoning in Horses

If you suspect your horse has consumed acorns, the first indication will be empty acorn husks in their droppings. If this happens, it’s essential to keep a close eye on them and be mindful of the following potential symptoms:

  • Reduced appetite

  • Lethargy

  • Constipation or diarrhoea

  • Depressed behaviour

  • Colic-like pain or abdominal pain

  • Ventral oedema (swelling of the lower neck and abdomen)

  • Potential kidney damage or kidney failure

  • Brown/red urine

  • Increased time spent lying down

  • Signs of dehydration

  • Clear discharge coming from eyes or nose

It’s worth noting that many of these signs are similar to those of other illnesses and health conditions. Because of this, identifying if your horse has acorn poisoning can be challenging without proper medical knowledge.

While you know your horse best, if you suspect they’ve ingested acorns and are experiencing subsequent illness, it’s wise to seek further advice from your veterinarian.

Early signs of acorn poisoning can be subtle and easily overlooked. This is why it’s essential to keep a watchful eye on them and contact your vet immediately.

Chalie perfecting the munch and roll technique

Horses noramlly roll just to scratch their backs, but if they seem like they are in discomfort you should investigate further. Fortunately Charlie was just having fun here.

Why Might a Horse Eat Acorns?

Fortunately, most horses don’t find acorns appetizing, which is why cases of acorn toxicity in horses are relatively rare. Horses are grazing animals so there is a chance they may accidentally consume some. But, there are also instances where they may be tempted to consume them.

For instance, fresh oak tree shoots can be quite tempting for horses if they’re bored or lack better-tasting alternatives like quality grass, grain, or hay. Overgrazed paddocks and reduced grazing quality can also increase the chance of horses eating acorns. Some may even develop an addiction.

Additionally, young horses are quite inquisitive and may end up overeating this new and interesting food.

So how can you prevent your horse from eating acorns and potentially getting acorn poisoning?

Tips to Prevent Acorn Toxicity in Horses

Given the unpredictable nature of acorn poisoning, it’s wise to take whatever preventative measures you can to minimize their exposure.

The most effective approach to dealing with acorn poisoning is to prevent it from occurring altogether. Managing your pastures to discourage horses from consuming acorns or oak leaves is key.

There’s no need to go chopping down oak trees in your pasture. The following tips are easy to implement and help prevent potential acorn poisoning:

  • Stop your horse from grazing under oak trees, especially when acorns are dropping – such as in autumn. You can do this by fencing off around the perimeter of the tree’s branch span.

  • Regularly rake up fallen acorns from the ground, especially green acorns.

  • Keep the branches trimmed and out of reach from your horses as oak leaves and branches also contain toxins.

  • Provide plenty of good quality forage to keep your horses satisfied. Unless your horse has a strong preference for acorns, they will prefer the forage.

Hay bale in the sun

Good quality forage will keep your horse full and stop them rooting around for other things to eat

What Are Some Horse-Friendly Alternatives to Acorns?

If your horse is rooting around for things to eat, you could try giving them these benefits from healthier – and safer – alternatives.

Good-quality hay or access to pasture is often sufficient to meet their nutritional need. But if you want to treat your horse occasionally or divert their attention from acorns when they get bored of their regular roughage, there are plenty of horse-friendly alternatives to try:

  • Apples (without the core)

  • Peaches (without the core)

  • Carrots

  • Celery

  • Oatmeal

  • Melon (without the rind)

  • Oranges (without the peal)

  • Pears (without the core)

Remember, even with these safe alternative treats, it’s key to offer them in moderation to your equine companion.

Squirrel eating an acorn

Acorns – best left to the squirrels


How many acorns can a horse eat before it develops acorn poisoning?

It’s impossible to predict how a horse will react or determine a “safe” amount before they could be affected by acorn poisoning. Not every horse is the same and some are more prone to acorn poisoning, so even a small amount can make them sick. That’s why it’s generally best to steer clear of acorns altogether and avoid any potential risks.

What is the treatment for acorn poisoning?

Currently, there is no specific treatment or cure for acorn poisoning, so your vet will primarily provide supportive care to manage symptoms. This may include intravenous fluids for dehydration and mineral oil and charcoal to help eliminate the tannin from the digestive system.

The prognosis is usually good as horses would need to consume a large quantity to experience acorn toxicity.

Can acorns be addictive to horses?

Sometimes (but rarely), a horse may develop a strong preference for acorns, often seeking them out over quality forage. The good news is, most horses will prefer their roughage as long as it’s high-quality and enough to keep them satisfied.

Similar Posts