Acorns, buckeyes, black walnut and yew: which native nuts and fruit poison dogs, horses and children, and which are food

Most native nuts and fruit are food or harmless, and a few can kill. Buckeye seeds and every part of a yew except its red flesh can poison a dog, a horse or a child. Wilted wild cherry leaves can kill cattle, sheep and horses within minutes. Acorns and oak leaves sicken grazing animals that eat them in quantity, and moldy black walnut husks give dogs tremors. Chestnuts, hickory nuts, hazelnuts, ripe mulberries, serviceberries, pawpaws and persimmons are food. For an animal that ate something, call a veterinarian, and for a person, call a poison center at 1-800-222-1222.

Which native nuts, seeds and leaves are poisonous, and which are food

The first table sets out eight native poisons by the part, who it harms and the signs. The second sets out nine nuts and fruit that are food.

Nuts, seeds and leaves that poison

The last column gives the part people eat, or the food the plant is mistaken for.

We do not grow horse chestnut, honey locust or the planted Japanese and English yews. Horse chestnut carries the same poison as the native buckeyes.

Nuts and fruit people eat

These are food for people when ripe, and the last column gives the catch where a source names one.

What acorns, black walnuts, buckeyes and yew do to a dog

Acorns can poison a dog, with kidney and liver damage on record, though the only harm may be a gut blocked by the nuts. The ASPCA’s plant list names oak as toxic to horses only, while the Merck Veterinary Manual records acorn poisoning in dogs. Oak leaves carry the same tannins, and the risk climbs with the amount eaten. On the ASPCA’s list, American chestnut, mulberry, the hawthorns and several hickories are non-toxic to dogs and horses.

Black walnuts turn dangerous to a dog once they mold. Molds that grow on fallen walnuts make toxins that bring vomiting, tremors and seizures, from one to several hours after a dog chews a husk or a nut. Most dogs recover in days to weeks, though some stay unsteady for months. What the same husks do to tomatoes and blueberries is the work of juglone, set out in what to plant under a black walnut.

A buckeye brings severe vomiting and diarrhea, wobbling and dilated pupils, and in bad cases seizures and coma. Yew can kill a dog suddenly through heart failure.

Call a veterinarian, or the ASPCA’s Animal Poison Control line at 888-426-4435, as soon as you suspect a dog ate any of these. A veterinarian has to tell moldy-walnut tremors apart from chocolate or pesticide poisoning, so say what the dog got into. For moldy walnuts, care means emptying the stomach if the dog has not vomited, activated charcoal, drugs for tremors and seizures, and fluids. Oak poisoning has no specific treatment beyond such supportive care.

Horses and cattle: acorns in a mast year, walnut shavings and wilted cherry leaves

Oak poisons cattle and sheep most often, but its colic and diarrhea are more severe in horses: in one series of horses poisoned by acorns, more than half died. The risk climbs with the amount eaten and when stock have little else, so a mast year, when acorns lie thick, is the fall to watch. Give other feed, keep animals off oak woods in a heavy acorn fall and rake up fallen acorns where you can. Goats tolerate tannins better than cattle do.

Three more trees each need a rule:

• Buckeye. Seeds and young shoots poison every grazing animal, bringing wobbling, twitching and paralysis, though deaths are rare. Keep stock away from buckeyes in spring and when the seeds fall.
• Black walnut shavings. Bedding that holds black walnut shavings brings lameness and swollen lower legs in a horse within a day, and laminitis if it stays. Remove it at once, and most horses improve within two days.
• Yew trimmings. Yew kills livestock fast, and poisoning usually follows when branches or hedge trimmings reach stock. Never dump yew clippings where animals graze.

Wild cherry is the storm hazard. Wilting turns natural compounds in black cherry and chokecherry leaves into cyanide, and signs start within 15 to 20 minutes of eating them:

“If cherry trees are within reach of animals in the pasture, beware of wilted leaves, because animals will readily consume them.” (Penn State Extension, Cyanide Poisoning of Livestock from Cherry Tree Leaves)

After a storm, clear any fallen cherry limb and rake up its leaves before stock go back in. Eastern red cedar is not on the ASPCA’s list of plants toxic to horses, though its cones and leaves can cause diarrhea when eaten in quantity.

Which wild nuts and fruit a child can eat

Ripe serviceberries, mulberries, pawpaws and persimmons are food for a child. So are chestnuts, hazelnuts, hickory nuts and beechnuts. Keep children from buckeyes, yew berries, raw elderberries, Kentucky coffeetree seeds and the pits of wild cherries and plums. A chewed or crushed pit releases cyanide, but one swallowed whole by accident usually passes without harm, so teach children to spit pits out. Even a harmless berry can upset a small stomach or choke a toddler.

Buckeyes are easily mistaken for chestnuts. A chestnut has a pointed tip with a little tassel and grows in a bur of dense spines that looks furry. A buckeye is glossy brown with a large pale scar, the buck’s eye of its name. The number of nuts is no test, since a buckeye husk holds one to three and a chinquapin bur holds one.

If a child eats a seed, berry or pit from the first table, call a poison center at 1-800-222-1222, free and open around the clock, without waiting for symptoms. For a buckeye, the advice is to wipe out the mouth, have the child rinse and spit, and give a few small sips of water. Every answer turns on the name of the plant:

“Find out the names of your plants. Expert help depends on accurate plant identification.” (National Capital Poison Center, Poisonous and non-poisonous plants: An illustrated list)

What edible means on a native tree

Edible on a native tree means some part of it is food, never that every part is safe. Blue Whale Trees marks black cherry, black walnut, chokecherry, white oak and black elderberry edible, and each of them has a poisonous part in the first table. The shop’s edible list gathers the trees and shrubs with fruit, nuts or berries to eat. Eat a wild nut or fruit only when you know for certain which plant it came from.

What to plant, and who to call

Start from what you need:

• Fruit and nut trees: the tree finder lists the trees and shrubs we grow with fruit or nuts to eat, by zone, size, sun and soil moisture. The Native Edible Orchard puts six of them together.
• A black walnut near the garden: what to plant under a black walnut sorts plants by how they take juglone.
• A nut or berry you cannot name: what tree dropped this keys out what eastern trees drop, and our support page takes questions about a tree you have, with photos by email.
• A pet that ate one: a veterinarian, or the ASPCA’s Animal Poison Control line at 888-426-4435.
• A child who ate one: a poison center at 1-800-222-1222.

Common questions

Are acorns and oak leaves poisonous to dogs?

They can be: oak tannins have given dogs kidney and liver damage, and swallowed acorns can block the gut. Call a veterinarian as soon as you know a dog has eaten them.

Are black walnut husks poisonous to dogs?

Yes, once they mold: moldy husks and nuts give dogs vomiting, tremors and seizures within hours. Rake up fallen walnuts where a dog runs, and call a veterinarian if one chews them.

Are buckeyes poisonous to touch?

No: none of the native buckeyes causes a skin rash, so handling one does no harm. The poison works when a seed, a leaf or a young shoot is eaten.

Can people eat acorns?

Yes, once the bitter tannins are soaked or boiled out. Raw acorns can bring stomach pain and constipation.

Sources

• Black Walnut: ASPCA Animal Poison Control Center, Toxic and Non-Toxic Plants, the entries for black walnut, buckeye, horse chestnut, oak, American yew, black cherry, chokecherry, plum, American chestnut, mulberry and shellbark hickory, with the lists for dogs and horses: moldy walnut husks and nuts giving dogs tremors and seizures and shavings giving horses laminitis, the signs of buckeye, yew and wild cherry poisoning, oak listed as toxic to horses only, the chestnut, mulberry, hawthorns and hickories listed as non-toxic, no juniper on the horse list, and the poison line’s number.
• Oak Toxicosis in Animals: Merck Veterinary Manual (Robert H. Poppenga, reviewed 2026): every oak potentially toxic, risk rising with the amount eaten and with little other feed, cattle and sheep affected most, goats resistant, the signs and the worse colic in horses, the horse series in which more than half died, kidney and liver damage or a blocked gut in dogs, supportive care only, and keeping stock off oak and raking up acorns.
• Tremorgenic Neuromycotoxicosis in Dogs: Merck Veterinary Manual (Michelle S. Mostrom, 2021), with the chapter Chocolate Toxicosis in Animals: molds on walnuts making tremor toxins, vomiting, tremors and seizures within one to several hours, recovery in days to weeks and unsteadiness for months, chocolate and pesticides among the poisonings to rule out, and the care a veterinarian gives.
• Range Plants of Temperate North America: Merck Veterinary Manual (T. Zane Davis, 2023), with the chapter Cyanide Poisoning in Animals (Scott Radke, 2026): buckeye seeds and young shoots poisoning grazing animals with rare deaths, black walnut shavings and laminitis in horses with recovery in a day or two, wild cherries killing within minutes, yew poisoning from branches and trimmings, Japanese and English yew as the common ornamentals, wilting raising cyanide, and seeds and leaves carrying more of it than fruit flesh.
• Aesculus flava: NC State Extension Gardener Plant Toolbox, the pages for yellow, Ohio, red, painted and bottlebrush buckeye, horse chestnut, white and northern red oak, black walnut, Japanese yew, black cherry, chokecherry, American plum, black elderberry, Kentucky coffeetree, red mulberry, downy serviceberry, pawpaw, American persimmon, American hazelnut, shagbark hickory, pecan, American chestnut, mayhaw and American beech: the poisonous parts, symptoms and animals for each, buckeyes causing no skin rash, the buck’s-eye scar, acorns edible once leached, cooked elderberries, the honey locust look-alike, and the edible fruit and nuts with their catches.
• Cyanide Poisoning of Livestock from Cherry Tree Leaves: Penn State Extension (Dwane Miller and Leanna Duppstadt, 2023): wilting turning cherry leaf compounds into cyanide, signs within 15 to 20 minutes, the quotation on wilted leaves within reach, and clearing fallen limbs and leaves before stock return.
• Poisonous and non-poisonous plants: An illustrated list: National Capital Poison Center, with the articles on horse chestnuts, swallowed cherry pits, yew and fall berries: the poison center number, help free and around the clock, the quotation on plant names, buckeyes mistaken for chestnuts and how to tell them apart, first aid for a child, chewed pits releasing cyanide while whole ones pass, yew seeds poisoning children, upset stomachs and choking from harmless berries, and eating wild plants only when certain.