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Horse

Foods

Yew

Taxus spp.

Also known as: yew tree, English yew, Japanese yew, yew berries, yew clippings, taxus

Danger (Avoid)

Yew is the most acutely lethal plant your horse is likely to encounter. There's no slow buildup, no window to notice symptoms, no time to call the vet. Horses have been found dead beside yew hedges with the leaves still in their mouths. This plant kills in minutes, and it grows in gardens, churchyards, and hedgerows everywhere.

Quantity

As little as 0.5 to 2 grams of yew leaves per kilogram of body weight can be lethal. For a 500kg horse, that's roughly a single mouthful of leaves. There is absolutely no safe amount and no margin for error.

Notes

Yew is extremely common in gardens, parks, churchyards, and as ornamental hedging — people don't realize it's lethal to horses because it looks so ordinary. Clippings thrown over a fence into a horse paddock are a leading cause of death. Even dried or dead yew retains full toxicity. The red berry flesh is the only non-toxic part, but the seed inside it is lethal. Neighbors trimming their yew hedges and dumping clippings near a horse fence is a tragically common scenario.

Negative Signs

* Trembling and muscle weakness
* Staggering and loss of coordination
* Difficulty breathing
* Dramatically slowed heart rate, then sudden collapse
* Sudden death — often the first and only sign

FAQ

Q: My neighbor has a yew hedge along the fence line of my horse's paddock. What do I do?
A: This is urgent. Talk to your neighbor immediately about the danger, and either get the hedge removed or install a solid secondary fence well back from the yew so your horse cannot reach over, through, or around to the leaves. A horse stretching its neck over a fence to browse on a yew hedge is one of the most common lethal poisoning scenarios. Don't wait — act today.

Q: Are yew berries safe since birds eat them?
A: Birds can eat the red flesh because it's the one non-toxic part, and they pass the seed through undigested. Horses chew and crush the seed, which is lethal. Nothing about the yew is safe for horses.

Alternatives

Remove yew from anywhere a horse can reach — including over fences, along paddock boundaries, and in neighboring gardens. Talk to your neighbors about yew. If you can't remove the trees, fence them off with a wide margin. Check paddock boundaries after storms, which can blow branches into fields.

Risks & Disclaimer

If you see your horse eating yew, this is the most urgent veterinary emergency possible. Call your vet while running to remove the horse from the source. Do not wait to see if symptoms develop. In most cases, by the time symptoms are visible, it is already too late. There is no antidote.