​As our horses and ponies are heading out to spring grass there are some nasty plants we need to keep our eyes open for.

There are many poisonous plants but thankfully only a few that our horses are likely to come into contact with. We do, however, need to be aware of these few in order to guard against the possibility of severe discomfort, illness or even death of our horses if ingested. In the wild, horses will graze a wide range of plant species and in many cases dangerous plants taste bitter and the horse will avoid them, but some plants are more insidious with a gradual toxin build-up.


One of the most recognisable poisonous plants is ragwort. It is very common and grows naturally in grassland, spreading by wind-blown seeds which can travel quite a distance. When growing fresh most horses will avoid ragwort but when dried - as in hay or cut/pulled plants left in the grazing area - it loses its bitterness and is far more palatable but no less toxic. In very heavily over-grazed areas, where horses are hungry and ragwort plentiful, it may be eaten out of desperation. The plant takes a year to develop before the familiar yellow flowers appear and can go unnoticed, so paddocks should be checked regularly for the first signs of the seedlings and frilly-leaved rosettes. Even if your horse is stabled you need to remain vigilant that there is none in your hay, check your hay regularly and always use a reputable and trusted supplier. Any ragwort found in your paddocks should be dug up, including the roots, and ideally the plants burned. It is advisable to wear gloves when handling ragwort.

Several familiar trees are considered dangerous. All parts of the yew tree are highly toxic to horses, and fatal poisoning happens almost instantly from only a very small amount. Horses should not be grazed anywhere that has a yew tree or hedge. Oak trees are another frequent cause of poisoning amongst horses, with acorns being the biggest culprit, and there is even evidence that some horses become ‘addicted’ to acorns and seek them out! Sycamores have been recognised as being linked to Atypical Myopathy, an often-fatal muscle condition. This is due to a toxin found with the seeds and, to a lesser extent, the leaves so autumn is a critical time for this condition. Fence off access to sycamore trees and remove any leaves or seedlings from paddocks – bear in mind that the ‘helicopter’ seeds can travel some distance, particularly in strong winds.

Dried bracken used to be used as a bedding for horses, and even a forage during lean times, but it is now known to be toxic when consumed in large quantities. Thankfully, there is no need to worry if your horse manages to grab a quick mouthful ‘snack’ of bracken while you are riding, but ensure the plant is removed from your fields to avoid long-term exposure.

Some plants such as deadly nightshade and larkspur (garden Delphiniums) are extremely toxic but also rare and unlikely to be found in a pasture but, especially if your fields are alongside gardens, these kinds of plants need to be considered. Others, such as foxglove are equally as poisonous but, as woodland plants, are unlikely to be found in well managed paddocks, but be aware, particularly if your field is near woodland.

Checking your paddocks, learning what plants are growing there, discovering if any are dangerous and practicing good pasture management will minimise the chance of your horse ingesting a toxic plant, but if you have any concerns talk to your vet. World Horse Welfare have produced a helpful leaflet listing some of the key plants that pose a threat to your horse, with photographs to help you identify them. Download it for free here: https://bit.ly/34Bv1TN You can find out more about good pasture management by contacting the World Horse Welfare Advice Line on 01953 497238.