Can horses eat onions?
No – toxic. Horses should never eat onions. ASPCA lists onions as toxic to horses because they can break down red blood cells. CliniTox (University of Zurich) describes anemia and jaundice in horses after eating wild onion.
Good to know: Rutgers (2004) still considered very small amounts probably acceptable; we follow the more cautious view.
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 onions. 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 – Onion (toxic to horses)
- CliniTox (Universität Zürich) – Pflanzengifte: Allium sp. (Zwiebel)
- Rutgers Equine Science Center – Fact Sheet #062: Odd Things that Horses Eat (reviewed 2004)
- RSPCA – What to feed your horse
Last checked: October 2026