Which plants are poisonous for horses?

While you might know exactly what your horse can eat, they’re not always the best at judging what’s safe and what isn’t. Whether your horse is on a ride or wandering around the paddock, it’s likely that they’ll graze on a few plants they see while they’re out and about.

Many plants are safe for your horse to eat, and they’ll happily munch along with no issues. However, some plants have the potential to be poisonous to horses if they consume them, so it’s important that you’re aware of them and inspect your pasture to keep your equine friends safe.

In this guide, we’ll look at:

• Signs of poisoning in horses
• Poisonous plants for horses
• How to stop your horse eating poisonous plants
• Non-toxic hedgerow plants for horses

Signs of poisoning in horses

If your horse eats something that is toxic to them, they may show some of the following symptoms:

Blindness Breathing difficulties Colic Collapse Constipation Convulsions Diarrhoea Dilated pupils Excessive salivation Extreme thirst Gait irregularities Hypotension (blood pressure with a MAP of less than 60 mm hg)

Irregular heart rate Jaundice Lack of coordination Lethargy Loss of appetite Muscle twitching Photosensitivity Recumbency Seizures Skin irritation Swelling around the face or neck Unsteadiness or lack of coordination Vomiting Weight loss

Poisoning can be fatal if left too long so, if you notice any of these symptoms, no matter how mild, then it’s important to contact your vet immediately.

Different poisons can require different treatments. In some cases, your vet can wash your horses stomach out to remove the poison. Alternatively, they may give your horse activated charcoal to absorb the poison, or laxatives to help the plant move through the body and reduce the amount of poison that is absorbed. So, if possible, your vet will need to know which plant your horse has eaten.

Unless you were with your horse when they ate the plant, it’s often difficult to determine what has caused the sickness as many plants can cause similar symptoms. Instead, it’s a good idea to inspect your pasture, paddock, and your horse’s feed. This also means you’ll be able to remove the plant from the area to prevent them eating it in future. If you can’t find anything, then your vet may be able to investigate your horses’ manure or stomach contents.

Poisonous plants for horses

Atypical myopathy (from sycamore poisoning) and acorn poisoning are the most common types of poisoning in horses, but there are many other plants here in the UK that can also be dangerous. To keep your horse safe and healthy, it’s a good idea to familiarise yourself with the different plants and trees that can be toxic to horses, so you can avoid them.

Some of the most common toxic plants that you’ll find here in the UK include:

Alsike clover Bluebells Bracken fern Buttercups Charlock Cherry trees (including wild and black cherry) Curly dock leaves Daffodils Deadly nightshade Foxgloves Hawkweed Hemlock (also called cow bane) Horse chestnut tree (conkers) Horsetails Ivy Laburnum Larkspur

Laurel Lily of the valley Maple trees Meadow saffron Monkshood Mistletoe Oak trees and acorns Pear trees Pigweed Privet Pyracantha (also called firethorn) Ragweed Rhododendron St. John’s Wort Sycamore Wisteria Yew

You can read more about these plants, including what they look like, where they’re found, and the symptoms of poisoning in the table below.

Plant name	Appearance	Where is it found?	Symptoms
Alsike clover		Pastures, fields, roadsides, and wasteland.	Photosensitisation Head pressing Yawning Recumbency Skin irritation Jaundice Weight loss
Bluebells		Woodland, hedgerows, and gardens.	Vomiting Diarrhoea Lack of urination Hypotension (blood pressure with a MAP of less than 60 mm Hg)
Bracken fern		Woodlands, heathland, moorland, and on hillsides, as well as the roadside.	Nervousness or agitation Muscle spasms Falling Unsteady gait A ‘tucked up’ appearance of the flanks Loss of appetite Constipation Diluted pupils Irregular heartbeat
Buttercups		Pastures, meadows, woodland, roadsides.	Excessive salivation Diarrhoea Colic Convulsions Blisters in and around the mouth Blood in urine Loss of appetite Low pulse rate Paralysis Swelling of the face
Charlock		Fields, pastures, roadsides, and wasteland.	Diarrhoea Difficulty breathing Bloating Frothing at the mouth
Cherry trees (including wild and black cherry)		Woodland, hedgerows, parkland, and gardens.	Irregular heart rate Laboured breathing Lack of coordination Agitation Excessive salivation Trembling or shaking Dilated pupils
Curly dock leaves		Grassland, roadsides, wasteland.	Difficulty breathing Lack of coordination Loss of appetite Muscle tremors Weakness Convulsions Erratic behaviour Excessive salivation Recumbency
Daffodils		Woodlands, parkland, roadsides, and gardens.	Lack of coordination Convulsions Diarrhoea Excessive salivation Hypotension (blood pressure with a MAP of less than 60 mm Hg) Tremors Photosensitivity Dehydration Irregular heart rate
Deadly nightshade		Woodland, grassland, heathland, and moorland.	Irregular heart rate Diarrhoea Loss of appetite Lack of coordination
Foxglove		Woodlands, heathlands, roadsides, gardens, and hedgerows.	Small pupils Difficulty breathing Convulsions Swelling around the face or neck Strong and slow heartbeat Weakness
Hawkweed		Grassland.	Unsteady gait Difficulty breathing Bending of the hock Knuckling over (straightened fetlock)
Hemlock (also called cowbane)		Riverbanks, ditches, and wasteland.	Trembling Confusion and disorientation Lack of coordination Frequent urination Diarrhoea Seizures Bloating Irregular heart rate Dilated pupils
Horse chestnut (conkers)		Woodlands, parkland, and roadsides.	Loss of muscle control Convulsions Tremors Hypersensitivity Colic
Horsetails		Meadows, wasteland, and grassland.	Loss of balance Loss of muscle control Nervousness and anxiety Paralysis Weight loss Staggering Convulsions Inability to stand
Ivy		Woodland, scrubland, wasteland.	Colic Diarrhoea Dehydration Irritation around the mouth Loss of appetite Excessive salivation Fever Weakness
Laburnum		Parkland and gardens.	Muscle spasms Convulsions Lack of coordination
Larkspur		Parks and gardens. Very rarely grows in the wild in the UK.	Muscle tremors Weakness Irritability Stiffness Confusion Constipation Collapse Nausea Bloating Irregular heart rate Seizures
Laurel		Woodland and hedgerows.	Irregular heart rate Diarrhoea Excessive salivation Hypotension (blood pressure with a MAP of less than 60 mm Hg) Weakness Tremors Seizures Blindness Lethargy Loss of appetite Difficulty breathing
Lily of the valley		Woodland and gardens.	Loss of appetite Nausea Diarrhoea Vomiting Weight loss Weakness Sleepiness Muscle tremors Convulsions Hypotension (blood pressure with a MAP of less than 60 mm Hg) Irregular or rapid heart rate
Maple trees		Woodland, scrubland, and hedgerows.	Lack of appetite Dark urine Lethargy Colic Increased heart rate Heavy or rapid breathing
Meadow saffron		On damp meadows, by riverbanks, or in woodland.	Colic Diarrhoea Weakness Difficulty breathing Difficulty swallowing Lack of coordination Irregular gait Extreme thirst
Monkshood		Woodland and gardens.	Irregular heartbeat Irregular or rapid breathing Excessive salivation Weakness Hypotension (blood pressure with a MAP of less than 60 mm Hg) Collapse
Mistletoe		On the branches of other trees, particularly hawthorn, poplar, lime, and apple trees.	Diarrhoea Colic Hypotension (blood pressure with a MAP of less than 60 mm Hg) Convulsions
Oak trees and acorns		Woodland, fields, hedgerows, gardens, and parkland.	Diarrhoea or constipation Colic Loss of appetite Foaming at the mouth Irritation around the mouth Frequent urination Excessive salivation Watery eyes Difficulty breathing Swelling around the face and neck High temperature Irregular heart rate
Pear trees		Orchards, gardens, and parkland.	Colic Diarrhoea
Pigweed		Fields and gardens.	Weakness Tremors Difficulty breathing Swelling around the face and neck
Privet		Scrubland, woodland, and hedgerows.	Diarrhoea Weak pulse Low temperature Increased heart rate Lack of coordination Staggering Convulsions Paralysis Dilated pupils
Pyracantha (also called firethorn)		Hedgerows and gardens.	Difficulty breathing Anxiety Confusion Vomiting
Ragwort		Pastures, sand dunes, roadsides, and wasteland.	Colic Diarrhoea or constipation Lack of coordination Sensitivity to sunlight Head pressing Blindness Collapse
Rhododendron		Woodland and heathland.	Colic Difficulty breathing Diarrhoea Excessive salivation Loss of appetite Paralysis Seizures Lack of coordination Weakness
St. John’s Wort		Woodland, grassland, and roadsides.	Diarrhoea Dilated pupils Sensitivity to sunlight Swelling of the skin Irritation or blistering of the skin Itching Lethargy Lameness
Sycamore		Woodland, hedgerows, and parkland.	Muscle stiffness Sweating Increased heart rate Dark urine Muscle tremors Reluctance to walk Weakness Difficulty breathing
Wisteria		Parkland and gardens.	Loss of appetite Extreme thirst Dehydration Diarrhoea Nausea Colic
Yew		Woodland and hedgerows (particularly in churchyards).	Diarrhoea Lack of muscle control Trembling Nervousness Convulsions Difficulty breathing Low heart rate Collapse

Is Japanese knotweed poisonous to horses?

 

Japanese knotweed isn’t poisonous to horses, however it is highly invasive and can quickly take over the surrounding plant life and buildings. If you notice any around your paddock or field, then it’s a good idea to contact a professional removal company who can treat and dispose of it correctly.

Are nettles poisonous to horses?

Stinging nettles are not toxic to horses and will not usually produce any symptoms of poisoning. However, nettles are known for the sharp stinging hairs present on their leaves which can cause irritation. For this reason, your horse will usually avoid eating them. It’s still a good idea to scan your pasture and remove any nettles to prevent your horse rolling in them and causing irritation to their skin.

Are lilacs poisonous to horses?

Most species of lilacs, such as common lilac, are not considered toxic and are safe for your horse to eat. However, Persian lilac can be poisonous if consumed. For this reason, it’s a good idea to keep your horse or pony from eating any lilac bushes.

Horses and clover poisoning

Aside from alsike clover (which is toxic), most other species of clover are safe for horses in small amounts and can actually provide your horse with lots of nutrients. However, if your pasture is over 10% clover, then there’s a chance your horse could overeat the plant and poisoning can occur. For this reason, it’s a good idea to check your pasture regularly and keep horses away from the area if it is filled with clover.

Overgrazing can encourage more clover to grow. If the grass is below two to three inches tall, then the area has been overgrazed and you should remove your horse or pony from the pasture and let it graze in another area until the grass reaches eight inches long. To avoid overgrazing in the long term, it’s a good idea to use a fence to separate your paddock in two and rotate your horse between them.

While most species of clover are non-toxic in normal amounts, some plants can carry the fungus slaframine which can be poisonous to horses. The fungus will appear as dark brown spots on the leaves and usually grows in cool, wet weather. Symptoms of slaframine poisoning include excess salivation, colic, bloating, stiffness, and diarrhoea. The good news is that slaframine poisoning is generally short-term, and your horse should recover within a few days.

If you notice that areas of your pasture have been infected with slaframine, it’s a good idea to remove your horse from the area and spray it with a herbicide to get rid of the clover. There are a range of herbicides on the market that are safe for use on horse pastures. Just make sure you follow the instructions on the bottle carefully.

Will your horse recover from poisoning?

If caught early, your horse should make a full recovery from being poisoned, but if left too late, liver failure can occur. After this time, treatment can be used to help the liver regenerate. However, sometimes the liver can become too damaged for the horse to recover.

In some cases, even small amounts of highly toxic plants, such as ragwort, could quickly lead to liver failure and lessen your horse’s chances of recovering. So, it’s best to make sure your horse avoids eating all toxic plants, particularly those that can be highly poisonous, such as ragwort, sycamore, oak, and yew trees, and bracken.

How to stop your horse eating poisonous plants

Unless they’re highly poisonous, your horse will need to eat large quantities of the toxic plant to be poisoned, and many toxic plants have a bitter taste that can deter your horse or pony from eating them. However, some horses aren’t put off by the taste and can continue to eat the plant anyway. To stop them eating them, it’s a good idea to look at the reason why they might be doing so in the first place.

In the pasture

Horses will usually avoid eating poisonous plants if they have an abundance of other food sources. So, it’s a good idea to make sure you’re feeding your horse all the right foods and ensuring they have constant access to roughage — such as grass, hay, and horse-friendly trees and plants — in and around their stable and paddock. This will help stop them foraging around for extra food.

It’s also a good idea to practice good pasture management by removing weeds regularly. This will allow grass to grow, giving your horse more to feed on.

Your horse will also be more likely to eat toxic plants if there’s a lot of them around the pasture, so it’s a good idea to check the whole area at least once a month and clear away any plants that could be poisonous. Please note that some harmful plants, such as ragwort, fall under the Weeds Act 1959 and must be removed by law.

For trees that could be hard to remove, you can put up extra fences to keep your horse away. It’s also a good idea to conduct a search of your paddock each time you turn your horse or pony out in case any leaves have blown off surrounding toxic trees.

As a horse owner, you know that you don’t always have full control over what your horse eats. Sometimes, well-meaning members of the public can give your horse a little treat as they walk past your field. To stop them giving your horse something they shouldn’t, it’s a good idea to put signs up around the area advising the public what is and isn’t safe to feed horses. You may also want to stop them from feeding your horse altogether by growing non-toxic plants and trees around the perimeter of your field.

In some cases, poisonous plants can be mixed in with hay if they’ve taken over hayfields. If you produce your own hay, you can avoid this by inspecting your fields and removing toxic plants. If you buy your hay from somewhere else, avoiding contamination is a little harder. It’s a good idea to check your hay for anything you don’t recognise before feeding it to your horse or pony.

On a ride

Horses are grazing animals and sneaking a bit of grass while on a ride is perfectly natural. Usually, this doesn’t cause any problems. But if you’re worried about what other types of plants they might be eating while out hacking, a quick pull on the reigns or a squeeze of the legs should deter them. If your horse doesn’t respond, then you may need to try again with more pressure until they listen.

Non-toxic hedgerow plants for horses

Now you know which plants are toxic for your horse, you might be wondering which trees and plants are safe. If you’re decorating your pasture, or would like to plant some shrubs and trees for privacy, then the following hedgerow plants, flowers, and trees would be a great option.

Hawthorn

Hawthorns are great non-toxic plants for horses, and the berries and leaves are often used in some equine health supplements due to its circulation boosting properties. This makes them perfect hedgerow plants for horses.

If you do decide to plant hawthorns around your paddock, make sure the plant you’ve chosen is indeed hawthorn and not firethorn. The two plants can look very similar, and are often mistaken for each other, however firethorn (also known as pyracantha) can be toxic to horses.

You can tell the difference between hawthorn and firethorn by looking at their leaves and berries. Firethorn has short leaves with a glossy finish and rounded berries. Hawthorn leaves are slightly longer, and the berries are a little more elongated, too. If you’re buying your plant from a garden centre, they’ll be able to advise on which type is which.

Hornbeam

Hornbeam is a very popular plant for horse-friendly hedgerows as it’s non-toxic and provides a great shaded area for your horse to rest in to keep away from the heat or flies. It’s also evergreen, which means it will keep its leaves and provide plenty of forage for your horse or pony all through the year.

Dogwood

Dogwood is another great hedgerow plant for your horses, and often grows wild in hedgerows and woodland. No part of the dogwood plant is poisonous, and your horse or pony will happily munch away if you plant some around your paddock.

Hazel

Hazel trees are another great hedgerow plant that is perfectly safe for your horse to eat. They’re fast growing, making them the ideal option for horses who graze a lot in their paddock, as they’ll keep them under control and prevent them from overgrowing.

Beech

Beech trees are considered safe for horses to eat, and they’ll often eat the leaves, twigs, and bark if they get the chance. In the spring and summer, these trees will provide a dense canopy of leaves, making them the perfect shaded spot for your horse or pony to rest and cool down.

Roses

If you’d like to decorate your paddock with a few rose bushes, then you’ll be pleased to know that roses are not known to be poisonous to horses. However, make sure you take care if you do plant any rose bushes, as your horse could injure themselves on the thorns. It’s a good idea to clip the thorns off or build a fence around the area to keep your horse or pony safe.

Sunflowers

Not only do sunflowers look incredibly pretty, but all parts of these large yellow flowers are horse-friendly. In fact, sunflower seeds, particularly black oil sunflower seeds, are rich in omega-6 fatty acids, which can help improve coat condition.

Lavender

The bright purple flowers of the lavender plant can help to brighten up your paddock, and the smell of the plant as its carried in the wind can have relaxing benefits for both you and your horse. Plus, it’s perfectly safe for your horse to eat.

Rowan

If you’d like to provide your horses with some privacy, or want to keep the public away from your pasture, then rowan trees would make the perfect addition to your hedgerow. These plants are non-toxic for horses, and while they won’t be very interested in eating the red rowan berries, they might nibble on the leaves.

Willow trees

Willow is another great horse-friendly tree for planting around your paddock. Many horses love eating willow leaves, and the drooping branches provide the perfect shaded spot for them to rest, cool down, and keep away from flies in the summer months.

It’s important to familiarise yourself with the different poisonous plants for horses. If you keep an eye out for these plants in your pasture, or while you’re out on a ride, you can help your horse stay safe and healthy.

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