Things you should never feed your horse

Horses are herbivores – an animal that feeds on plants. Their digestive systems are highly sensitive, and they are unable to vomit, so it can be dangerous for horses to eat something they can’t digest.

Your horse’s stomach contains good bacteria created to break down the food they eat every day. If their daily diet changes suddenly, your equine friend may be at greater risk of health concerns like colic – which is why it’s worth making any adjustments slowly.

Constant access to fresh, clean water is essential for your horse’s health.

Equines need lots of fibre from forage too, so don’t hold back with the hay!

To feed or not to feed? Let’s explore what not to feed your horse…

Two horses eating hay

Mouldy forage

Hay or haylage that has been stored incorrectly, or cut from poor quality pasture, may become mouldy and will be inedible for your horse.

Unsuitable hay or haylage has an unpleasant or strong smell, rotten sections that are darker or lighter (depending on the type of mould), and it may be difficult to pull apart or full of spiky or poisonous plants.

Poor quality feed

Always check the ‘use by’ and ‘best before’ dates on bags of feed, but don’t rely on them to inform you about the quality of that feed, due to the way it may have been stored before you bought it.

Use your common sense when deciding whether feed is safe for your horse; it shouldn’t be mouldy or dusty, for example. Good quality horse feed will look nice and smell pleasant.

Food for other animals

Food that has been created for other animals will not be suitable for your horse.


It’s never acceptable to feed horses meat of any description.

Meat by-products

Anything you feed to your horse should be free from meat by-products, too. For example, horses cannot digest products like gelatine.

Grass clippings

Once your lawn has been mowed, the grass clippings have already started to ferment and break down. By the time grass clippings reach your horse’s stomach, they’re fermented and can cause colic.

Gloved hand holding grass clippings.

Garden cuttings

As with grass clippings, it’s dangerous to feed garden cuttings to your horse. Another risk of garden cuttings is that they may contain poisonous plants.

Processed foods

Heavily processed food can be harmful to horses, e.g. pot noodles, crisps, biscuits, etc.


While it may be tempting at times, don’t feed your horse sweets. It doesn’t matter how sweetly they ask for a tiny taste, sweets aren’t safe for horses!


Like dogs and cats, horses can’t eat chocolate due to a toxic chemical, ‘theobromine’. The symptoms caused by consumption of theobromine include colic and seizures.


Peppermints are generally considered safe for horses, however, it’s vital that horses are not fed mints that may contain animal by-products. Plus, horses should never consume chewing gum or mints that are chewy.


If you’re lactose intolerant, you have that in common with your horse!

Equines aren’t able to consume dairy. Even small amounts of dairy cause diarrhoea in horses, whereas large amounts of dairy will cause colic.


Although people used to think feeding bread to horses was harmless, it has been discovered that bread can cause a blockage in your horse’s digestive system, leading to colic.


Part of the ‘Allium’ family of plants, onions are toxic to horses because they damage red blood cells and cause anaemia.

Other members of the Allium plant family your horse cannot eat:

  • Leeks.
  • Shallots.
  • Chives.

Please note: Garlic is an Allium plant, however, small amounts of garlic are safe for your horse to eat in the form of a specially designed feed supplement; if you have any doubts about feeding garlic to your horse, ask your vet for advice!

Deadly nightshade

Nightshades are a family of plants, not just the flower.

All nightshade plants are toxic to horses, and deadly nightshade can cause symptoms such as dilated pupils, blindness, and muscle tremors.


Tomato plants are related to deadly nightshade. ‘Atropine’ is found in tomato plants and can cause colic in horses because it slows down digestion.

The tomato itself contains ‘hyoscyamine’, which increases your horse’s heart rate and damages their digestive system.


Raw or cooked, potatoes are poisonous to horses!

Due to being part of the nightshade family of plants, potatoes are not safe to feed to your horse.

Potatoes on a chopping board, with a potato peeler.

Fruit with stones and seeds

In the same way fruit with pips and pits aren’t safe to feed to your horse, fruit with stones and seeds aren’t suitable for horses either because they’re a choking hazard and may contain toxins.


Symptoms observed in horses who have eaten avocado include difficulty breathing, an irregular heartbeat, and colic.


If they eat rhubarb, horses can suffer from tremors and urinary tract problems that can lead to kidney failure.  


Avoid sharing a cup of coffee or tea with your equine friend!

Not only can caffeine cause an irregular heartbeat in equines, it can also lead competition horses to fail drug tests.


Cruciferous vegetables, like cabbage, contain ‘raffinose’ – which is known to cause intestinal gas. Your horse may end up suffering from colic if they eat cabbage or any other type of cruciferous vegetable:

  • Broccoli.
  • Cauliflower.
  • Brussels sprouts.


Traditionally, bran was fed to horses as a mash because it was thought to ease digestive discomfort. However, it has since been discovered that bran causes vitamin and mineral deficiencies in horses, so it is no longer considered safe to feed.

Poisonous plants

All poisonous plants must be pulled up, including their roots, and disposed of safely.

The devastating impact of poisonous plants can be avoided, if you know what to look for in your horse’s field.

Some of the plants that are poisonous to horses include:

  • Ragwort.
  • Acorns.
  • Foxglove.
  • Ivy.
  • Yew trees.
  • Sycamore.
  • Privet.
  • Laburnum.
  • Buttercups.
  • Hemlock.
  • Alsike clover.
  • Bluebells.
  • Wisteria.
  • St John’s Wort.
  • Laurel.
  • Mistletoe.
  • Bracken.
  • Daffodils.
  • Curly dock. 
  • Horsetail/marestail.
  • Meadow saffron.
  • Rhododendron.
  • Maple trees.
  • Horse chestnut trees.

Ragwort plant in a field.

Visit our visual guide to poisonous plants to learn more.

If you think your horse might have eaten something toxic, please contact your vet immediately.

Don’t forget, you can always ask your vet for advice about poisonous plants if you don’t know what they look like, or need to know how to remove them safely!

Safe snacks

In need of a safe snack for your horse?

Just as with humans, horses can enjoy very small amounts of tasty treats without unpleasant side effects. Provided they’re offered in tiny portions, you’re able to safely feed the following food to your horse:

  • Carrots (cut lengthways, to avoid choke!).
  • Bananas.
  • Watermelon.
  • Apples (without the core!).
  • Strawberries.

Looking for more horse advice?

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