Can horses eat acorns?
No – toxic. Horses should never eat acorns. ASPCA lists oak as toxic to horses, and acorns can also obstruct the digestive tract. The Merck Veterinary Manual describes severe gut damage with diarrhea and colic in horses.
Good to know: Merck’s pet owner version reports malformed foals and abortions in mares that ate acorns during the second trimester. With plenty of good hay, most horses leave oak litter alone (Rutgers).
Did your horse eat some?
Stay calm and call your vet or an emergency vet right away – never watch and wait (RSPCA). Tell them what your horse ate, how much and when.
- ASPCA Animal Poison Control: (888) 426-4435 (a fee may apply)
- Keep a leftover, the packaging or the plant.
Better choices, for example
Questions
My horse ate acorns. What should I do?
Stay calm and call your vet right away, even if your horse seems fine – never watch and wait (RSPCA). Tell them what your horse ate, how much and when.
Sources
- ASPCA Toxic and Non-Toxic Plants – Oak (toxic to horses)
- Merck Veterinary Manual – Oak Toxicosis in Animals
- Merck Veterinary Manual (Pet Owner Version) – Quercus Poisoning (Oak Bud Poisoning, Acorn Poisoning)
- Rutgers Equine Science Center – Ask the Expert: Are oak leaves, acorns, and bark toxic to horses?
- CliniTox (Universität Zürich) – Pflanzengifte: Quercus sp. (Eiche)
- Redwings Horse Sanctuary – Fuss, don’t feed!
- RSPCA – What to feed your horse
Last checked: October 2026