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Nuts a Horse Cannot Eat

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The horse is a natural grazer, and when he is provided with plenty of good forage his interest is rarely swayed by other available foods. Generally, they must be hungry to consume potentially dangerous foods. For instance, a horse may ingest nuts from time to time without repercussion. But certain nuts can cause a variety of health problems or even death. Knowing which trees are dangerous will help you keep them out of horses' reach, safeguarding his health and preventing poisoning.


Buckeyes, also called horse chestnuts, are the product of the Ohio buckeye or American buckeye tree. Buckeyes contain the toxin aesculin as well as tannic acid, the toxin found in acorns. A horse who has ingested buckeyes may appear excited, may have convulsions or diarrhea, and may exhibit coordination problems, according to the American Society for the Prevention of Cruelty to Animals. Animals may be prone to eating the plants and their nuts when other forage is scarce. Young spring plants are the toxic than mature trees. Keeping your animals from grazing in woodland areas can prevent buckeye poisoning.

Black Walnuts

The ASPCA reports that no known toxin is responsible for poisoning in horses, but ingestion of the nuts or their hulls can cause digestive problems. But interestingly, bedding crafted from the wood of a black walnut tree is toxic to horses, and exposure can cause such health problems as laminitis, depression, fluid buildup in the legs and colic. When ingested, black walnuts can cause laminitis and colic. A particular mold found within the husk of the nut can cause liver cancer. Due to the highly toxic nature of the tree and its nuts, caregivers may choose to keep their horses safe by pasturing them a good distance from black walnut trees.


Acorns, the product of oak trees, are toxic to horses when ingested in large quantities. Though horses won't typically seek out the nuts due to their bitter taste, lack of quality forage may send horses searching for alternative food sources -- and they may pick up a few accidentally while foraging. Horses may develop an addiction to acorns, actively seeking them even if a healthier choice is readily available, according to the website PetMD. Concerned caregivers can remove oak litter from a horse's pasture and pasture interested equines in enclosures lacking oak trees. Since acorn poisoning can mimic symptoms of other serious health conditions, seeking a veterinarian's counsel is prudent.

Sago Palm

Sago palms thrive in warm places like Florida, Texas and Southern California, and they can be found inside many homes as decorative house plants. While all parts of the plant are toxic, the nuts of the plant contains the highest levels of the poison cycasin. Animals tempted by the easily digestible nuts may suffer consequences of cycasin poisoning including diarrhea, depression and lack of coordination. As there is no antidote, a veterinarian may treat an affected animal with charcoal for toxin absorption, plus other drugs to support liver function.