Can they eat it? / Foxglove
Can horses eat foxglove?
Never. Acts on the heart; dried in hay it is still deadly.
A garden and roadside plant. Horses rarely eat it fresh but will in hay.
Irregular heartbeat, colic, diarrhea, collapse.
Call your vet now. Note what was eaten, how much and when; do not wait for signs.
Why it is dangerous
Foxglove (Digitalis purpurea) contains cardiac glycosides, compounds that act directly on the heart muscle and disrupt its electrical rhythm. The toxins stay active when the plant is dried, so foxglove that ends up in hay is just as dangerous as fresh plant. Even small amounts can cause an irregular heartbeat and collapse, and signs may take hours to appear.
How much is too much
For a 1,000 lb horse there is no safe amount of foxglove, fresh or dried. A single leaf or a few mouthfuls of hay containing it can be enough to cause serious harm. Ponies, miniatures and horses with heart or metabolic conditions are at even greater risk. Treat any exposure as an emergency, however small it looks.
Horses
Horses in work or at pasture are at risk mainly from foxglove growing along fence lines, in ditches, or in gardens next to paddocks. Check every field and roadside edge, and inspect hay before feeding it, since dried foxglove blends in with other leaves. Remove any plants you find, wearing gloves, and call your vet immediately if you suspect a horse has eaten any.
Ponies and easy keepers
Ponies, miniatures, seniors and easy keepers are especially vulnerable because their smaller body size means a smaller dose causes greater harm. Horses with heart or metabolic problems may also react more severely. Keep foxglove out of reach entirely, and make sure any hay you buy for these horses is checked for stray plants before it is fed.
Safe alternatives
Offer good-quality grass hay, which is safe and forms the foundation of a healthy diet. For a treat, use a small handful of plain carrot pieces or a few apple slices, cut into bite-size pieces to avoid choke. Always introduce new foods slowly and in small amounts.
Questions people ask
Can foxglove in hay hurt my horse?
Yes. Foxglove stays toxic when dried, so it is dangerous in hay. Inspect hay carefully and call your vet right away if you find any.
My horse ate foxglove after a frost. Is it safe now?
Frost does not remove the toxins. Treat it as an emergency, call your vet now, and note what was eaten and when.
How much foxglove is too much for a horse?
There is no safe amount. Even a small quantity can affect the heart, so contact your vet immediately rather than waiting for signs.
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.