Plants toxic for Horses. Yew. An image of the Yew Tree.

Which plants are most toxic to horses? In this series of posts, I continue to describe the most common plants that are toxic to horses.


Yew (Taxus baccata) is an evergree tree, native to Britain. It can grow to 20m in height. It grows in gardens, and churchyards all over Britain. Some trees reach 600 years old.

What the herbalist says:

The herbalist Culpeper tells us that: Yew grows to be an irregular tree, spreading
widely into branches. The leaves are long, narrow, and placed with a beautiful regularity.
The flowers are yellowish, and the berries are surrounded with a sweet juicy matter. It grows in woods, and in gardens. This is a tree of Saturn. The leaves are said to be poisonous; but the wood, if it grew with more regularity, would be very valuable. This tree, though it has no place among medicinal plants, yet it does not deserve (at least in our climate), so bad a character as the ancients gave it, viz, a most poisonous vegetable, the berries of which threaten present death to man or beast that eat them; many have eaten them in this country and survived.

The active agent:

The poisonous agents in Yew are toxic alkaloids. Amongst these are Taxine and Taxol. These are absorbed in the gut, and can impact the heart. The alkaloids are not present in the red berries. Rather, they are present in all other parts of the tree. The toxins are not rendered inactive by drying. Clippings of Yew can thus be of danger to animals. Following ingestion, there may be a loss of coordination in the animal, and variable pulse. In some cases, there are no symptoms at all, and the animal collapses a couple of hours after ingestion.

Herbal Medicine

In herbal medicine, tinctures of Yew have been prepared from the young shoots. Skin eruptions, cystitis, headaches, gout and rheumatism.

A Yew in the Paddock?

Looking at forums such as Horse and Hound, it is clear this is an issue for yard owners and users. Some ensure the tree is fenced off, or mown around so that horses will not graze up to it. One yard manager felt that as an evergreen there is no shed. In fact, Yews do shed needles, and some have noticed large reduction of needles. This can take place between every four and seven years. I would look before purchasing land – as a yew is a stately and large tree. It would be a shame to cut down such a tree. If one is on your land, it would seem safer to ensure that it is well fenced off. And all windfall is removed after high winds.


Other articles about plants appear on my Professional Facebook Page.
If there is a plant you would like me to write about, please get in touch via Contacts.

Quarterly Holistic Newsletter

If you have enjoyed this article, please keep in touch and sign up for our Quarterly Holistic Newsletter.

Keith Allison: A guide to Plants Poisonous to Horses. J.A. Allen. Revised edition, 2011.
John Gerarde: The Herball or General Historie of Plantes, 1636.
Culpeper: Index Of Herbs By Nich. Culpeper, Gent. Student in Physick and Astrologie, 1616, 1654

Please follow and like us: