Can they eat it? / Alsike clover
Can horses eat alsike clover?
Careful. Liver damage and sun sensitivity with heavy grazing.
A pasture legume that is fine in small amounts but causes trouble when it dominates a wet field, especially when mouldy.
Sunburn on white skin, dullness, yellow gums.
Move the horse off the clover and call your vet.
Why
Alsike clover contains photosensitizing compounds, mainly phytoestrogen-like and related substances, that the liver normally breaks down. When a horse eats a lot, especially from a wet or mouldy stand, those compounds build up and can damage the liver. Sunlight then reacts with the leftover pigments in the skin, causing sunburn-like irritation, most obvious on white or pink areas.
How much is too much
A few mouthfuls mixed into a mostly grass pasture is generally not a concern for a 1,000 lb horse. A field where clover makes up most of the forage, or a horse grazing it for days, is where trouble starts. Ponies, miniatures and metabolic horses may react to smaller amounts, so limit their access. Mouldy clover carries more risk at any quantity.
Horses
Horses in work or at pasture should not be allowed to graze a field dominated by alsike clover, especially after rain or when hay is mouldy. Keep the stand under control, rotate fields if needed, and make sure there is plenty of grass and hay so clover is never the main feed. Watch for sunburn on white legs, nose and muzzle during warm, sunny weather.
Ponies and easy keepers
Ponies, miniatures, seniors and easy keepers are more sensitive to rich forage and should be kept off clover-heavy pasture entirely. Insulin-resistant or laminitis-prone horses also need a grass-based diet, so avoid lush clover patches. Provide shade and a fly sheet with a face mask for light-skinned animals in sun.
Safe alternatives
Offer a clean grass hay such as timothy or orchardgrass, or a grass-only pasture mix. For a treat, a small handful of plain carrots or a bit of apple, cut into pieces to prevent choking, works well. Always introduce any new feed gradually and keep fresh water available.
Questions people ask
Can alsike clover in hay hurt my horse?
It can, particularly if the hay is mouldy or was baled damp. Have hay checked, keep it dry and watch for sunburn or dullness after feeding.
Is alsike clover dangerous after a frost?
Frost does not make it more toxic on its own, but stressed or damaged plants can grow mould. Keep horses off heavy clover stands in cold, wet weather.
What should I do if my horse ate a lot of alsike clover?
Move the horse off the clover and call your veterinarian right away. Do not wait for symptoms, since liver effects can build quietly.
Careful for horses means: fine in a small amount, prepared as described, and not for every pet; the details say when to skip it.
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.