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20 Things You Should NEVER Feed Your Horse

Republished from

Let’s be honest we all like to spoil our horses with treats from time to time but are you feeding them the right thing? While we all know that you should never feed ragwort to horses, be honest how many of you knew that bran isn’t good for them either?


Many people think that horses, like all grazing animals, can eat all types of plants without suffering any ill effect from them. After all who hasn’t experienced their horse diving his head into a bunch of stinging nettles to eat as many as he can? Some plants, however, can be as deadly to horses as they are to us. The most important plants to avoid are:


Ragwort is one of the most important plants to NEVER feed your horse. It contains pyrrolizidine alkaloids which are extremely toxic to horses. The toxins build up over time and cause irreparable liver damage which will quickly result in liver failure and ultimately death. Ragwort is so toxic that it can even be harmful to humans (although there’s no risk of serious liver damage) if it gets onto your skin, it’s for this reason that you should always wear protective gloves when removing it from any grazing pastures.


All types of privet are highly poisonous to horses but the box privet is the most dangerous, even in small amounts it can prove to be fatal.


A member of the digitalis family foxgloves are so poisonous that eating just a 100g can kill a perfectly healthy horse in just a couple of hours.

Deadly nightshade

While the name ‘deadly’ is an obvious clue that it’s toxic it’s worth noting that other plants in the same family should also be avoided. Plants such as mandrake, tomato, potato, tobacco and eggplant all belong to the nightshade family. Mild cases can result in colic like symptoms and increased heart rate but sadly it can resulting death.


Even if it’s dried and fed as hay bracken (or bracken fern as it’s sometimes called) can still be extremely toxic to horses and will, if not treated quickly, be fatal. Horses won’t naturally choose to eat bracken but will if it’s been picked a fed to them.


This plant, which produces spores rather than seeds, is extremely toxic to horses. Like a lot of plants that are harmful to horses its toxins, which destroys the vitamin B in the horse’s blood, become more potent when they’re dried. The effects of feeding horsetail are a weakness (especially in the muscles) and an increased arrhythmic pulse that can, in a lot of cases, sadly prove to be fatal.


Milkweed is extremely toxic to horses and can cause spasms, loss of control of muscles and even affect the horse’s heart rate. In extreme cases, it can paralyze the muscles around the lungs. As a rule, horses won’t eat milkweed but if they don’t have enough good quality food or grazing they could end up eating it. Unlike some other toxic plants though milkweed is very rarely fatal to horses.

Lawn or garden cuttings

While horses can eat grass until the metaphorical cows come home they should only eat fresh grass. As soon as the grass is cut it starts to ferment and when it reaches the horse’s stomach it continues to ferment and expand. This can result in colic and, in extreme cases, can rupture the stomach. While grass naturally eaten by horses will still ferment, this process won’t start until it’s moved much further along the digestion tract.


You might be surprised to know that you shouldn’t feed horses buttercups, doing so can irritate their mouth and cause diarrhea as well as colic. Generally, horses will graze around them and if they’re dried in hay or have been frozen (ie during winter) they will no longer be toxic. That said though you shouldn’t feed them to horses anyway.

There are a large number of other plants, such as Laurel and Red Oak (including acorns), that can be harmful to horses and cause symptoms such as colic and diarrhea, but the plants listed above are the most important to avoid.

Fruit and Vegetables

While things such as carrots, apples and watermelon are perfectly okay for you to feed to your horse you may be surprised to know some of the things you should never feed to horses.


It’s not just the fruit of avocados that’s toxic to horses but every single part of the tree is too, from the fruit to the leaves and even the bark. They can cause a very irregular heartbeat as well as breathing issues, colic and in some cases death.


Being from the same family as the deadly nightshade tomatoes contain an alkaloid known as atropine that can not only cause colic and digestive problems but also increase your horse’s heart rate. Generally, horses don’t like the taste of tomatoes so they won’t choose to eat them but if they’re in your sandwich, for example, it could disguise the taste.


Like tomatoes, potatoes are part of the deadly nightshade family and should never be fed to horses. If nothing else they can pose a choking hazard to your horse but are also toxic to horses, especially if they’re green or are rotten.


Containing high levels of calcium oxalates rhubarb is not only toxic to horses but a large number of other animals too. They can cause tremors and, if the horse ingests enough, kidney failure.

Garlic, onions, chives and leeks

While garlic supplements are perfectly okay to feed to horses raw garlic, onions, chives and leeks should only be given in very small amounts. They all contain N-propyl disulphide which can cause anemia in horses. As a ‘by the way’ footnote, it’s the N-propyl disulphide that makes our eyes water when cutting onions.

Unpitted fruit

While a large number of fruits are perfectly safe for your horse to eat you should only ever feed them fruit that has had the stone or seeds removed. Along with containing small amounts of toxins (such as arsenic in apple pips and cyanide in peaches) they can increase your horse’s chance of choking.

Other foods you should never feed your horse

Feeding things like moldy or dusty hay to your horse is common sense but there are a number of other things you shouldn’t feed your horse.


In the past, it was thought that bran was good for horses but recent studies have shown that it can cause a mineral imbalance and have a negative effect on their digestion which will cause diarrhea.

Cattle feed

You might think that horses are able to eat cattle feed but this isn’t the case. Horses and cattle are very different animals with totally different digestive systems and what is okay for one could prove fatal to the other. Likewise, you should never feed something meant for horses to cattle either.

Dairy produce

Like a lot of animals, horses are in fact lactose intolerant and eating dairy products such as milk and cheese can cause severe diarrhea. In some cases continued consumption of lactose can cause colic and other digestive issues.


While you might think its kind to share your sandwich with your horse this can block their digestive system and cause colic. Horse’s aren’t able to break down processed foods so it ends up causing an obstruction in their digestive tract.


Containing a toxic chemical called theobromine, chocolate can be fatal to horses if they digest large quantities of it. In smaller doses, it has a similar effect to caffeine which could result in competition horses failing a drug test and ultimate disqualification. You may be interested to know that theobromine can also be toxic to humans! It’s the speed at which our body metabolizes theobromine that prevents use suffering any effects from it when we eat a ‘normal’ amount.

So what is good to feed my horse?

After all of this talk of things you should never feed your horse you may be starting to worry about what is actually safe to feed him. Like all treats its always best feed them in moderation so if you’re going to feed your horse treats then don’t overdo it. That said as long as you remove any pips, seeds or stones and the skin or peel as well as cut them so there’s no chance of your horse choking them all of these make great treats. 




Melons (especially watermelon)





Berries (especially strawberries)


Grapes (including raisins)

Green beans


Citrus fruits



You would never eat something yourself if you weren’t sure if it was okay to do or not so why would you consider giving it to your horse! If you’re not sure if something is safe for your horse or not then it’s always better to avoid it. 

I hope you found this article helpful if you did I’d be grateful if you could share it please as it would really help me.

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