Can they eat it? / Black walnut shavings
Can horses eat black walnut shavings?
Never as bedding. Laminitis within hours of standing on it.
Fresh black walnut wood in shavings causes laminitis after as little as 12 hours of contact. Buy bedding from a known source and ask what wood it is; dark, aromatic shavings are the warning.
Heat in the hooves, reluctance to move, rocked-back stance, swollen legs.
Get the horse off the bedding, hose the legs, and call your vet.
Why it is dangerous
Black walnut (Juglans nigra) wood contains a compound called juglone, along with related tannins and phenolic compounds. When fresh walnut shavings are used as bedding, these substances are absorbed through the sole and are thought to disrupt blood flow within the hoof, which can trigger laminitis. The reaction can appear within hours of contact, so the bedding is the first thing to check. Dark, aromatic shavings are a warning sign.
How much is too much
For a 1,000 lb horse, there is no safe amount of black walnut shavings to use as bedding, because the harm comes from prolonged contact with the hoof rather than from a dose. Even a few hours of standing on it can be enough to cause problems. Ponies, miniatures and metabolic horses are at least as vulnerable, and in many cases more so, so the same rule applies to every horse.
Horses
Full-size horses in work or at pasture should never be bedded on black walnut shavings, even briefly. Stalls, trailers and run-in sheds are common places where walnut shavings sneak in. Ask your bedding supplier what wood the product is made from and keep a close eye on any new bedding you bring in. Check the feet and legs of any horse that has been standing on a fresh batch.
Ponies and easy keepers
Ponies, miniatures, seniors and horses prone to insulin resistance or laminitis are especially sensitive, and their hooves can react faster and more severely. Never use walnut bedding for these horses, and be wary of any dark, aromatic wood shavings. If you notice unusual heat in the feet or a reluctance to move after a bedding change, act immediately and call your vet.
Safe alternatives
Choose bedding made from pine, aspen or straw, which are commonly used and well tolerated. Look for kiln-dried shavings from a reputable mill, and ask the supplier to confirm the wood species. Spread bedding deeply enough that the horse is not in direct contact with any single layer for long periods.
Questions people ask
Can black walnut shavings be in hay?
Hay is not usually made with walnut, but walnut shavings can be mixed into bedding or used in stalls. If you are unsure what is in your bedding or hay, ask your supplier and watch the horse's feet.
What if my horse ate black walnut shavings?
Eating a small amount of shavings is different from standing on them, but either way, contact your vet promptly. Watch for signs of hoof pain, heat or a stiff gait, and do not wait for symptoms to worsen.
Are aged or composted walnut shavings safe?
Aged or composted walnut is less likely to cause problems, but there is no reliable way to confirm it is safe for a horse's feet. Keep walnut bedding away from horses entirely to be safe.
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.