Can they eat it? / Ragwort and groundsel (Senecio)
Can horses eat ragwort and groundsel (senecio)?
Never. Slow liver damage that shows months later.
Horses avoid the fresh plant but eat it readily in hay, where it keeps its toxins. Damage builds with every mouthful over months. Pull it before it seeds and check hay fields.
Weight loss, dullness, photosensitivity (sunburn on white skin), yellow gums, head pressing; often months after exposure.
Call your vet; blood tests show liver damage before signs do.
Why it is dangerous
Ragwort and groundsel (Senecio species) contain pyrrolizidine alkaloids, which the liver converts into toxic metabolites. These damage liver cells and block their repair, so harm builds slowly with each exposure. The alkaloids survive drying, so the plant stays dangerous in hay. Fresh plants are bitter and usually avoided, but once cut and dried the taste is masked and horses eat it readily. There is no way to reverse established liver scarring.
How much is too much
There is no safe amount of ragwort or groundsel for a horse, whether a full-size horse, a pony, or a miniature, and no level has been established below which the plant is harmless. Damage is cumulative, so small amounts repeated over weeks or months add up as much as one large dose. Even a few stems in a hay net contribute. Metabolic horses and ponies may not show signs any sooner, and their liver disease can be just as hard to spot. Treat any exposure as a concern.
Horses
Full-size horses at pasture or in work are most often exposed through contaminated hay, especially from fields left to seed or cut without removing the plant. Check every bale and net you feed, shake out hay and look for yellow flowers or the coarse, lobed leaves. Walk fences and field edges in summer and autumn and pull plants before they set seed, wearing gloves. Keep a hay log so you can trace a problem back to its source if signs appear.
Ponies and easy keepers
Ponies, minis, seniors and insulin-resistant or laminitis-prone horses are not more resistant to this toxin, and their liver problems can be harder to read because they already have chronic issues. Watch closely for weight loss, dullness or changes in attitude, and pay attention to any new sensitivity to sunlight on white skin. Ask your vet to check liver values during routine bloodwork, especially if your horse is on a field or hay you cannot fully verify.
Safe alternatives
Offer clean, tested grass hay that you have inspected yourself, shaken out and checked for weeds. Fresh pasture that has been walked and cleared of Senecio is another option. A ration balancer or a measured amount of plain alfalfa can add nutrition when hay quality varies. Always check labels and ask your supplier where the hay was grown.
Questions people ask
Can ragwort be in hay?
Yes. The toxins stay active after drying, and horses often eat dried ragwort in hay more readily than fresh. Inspect every bale and net before feeding.
My horse ate ragwort. What should I do?
Call your veterinarian promptly, even if your horse looks well. Liver damage can be found with blood tests before any signs appear.
Is ragwort banned in competition?
Rules vary by organization and country. Check the rulebook for your discipline and ask your veterinarian or governing body, since some competitions require a clean, weed-free feed and paddock.
Toxic for horses means: do not give it; if they ate it, call your vet or a poison line.
General information from veterinary guidance, not a diagnosis. If you are worried, call your vet or a pet poison line: ASPCA Animal Poison Control (888) 426-4435. Charges may apply.
Written by Hoofdeck editors · updated Nov 13, 2026 · from ASPCA Animal Poison Control, Merck Veterinary Manual and university extension guidance.