PupkeeperToxic
Can dogs eat onions? No: toxic
Toxic. Onions in any form, raw, cooked or powdered, can damage a dog's red blood cells and cause anemia, often days later.
If your dog ate or touched this, call your vet or a pet poison line now
United States
Poison lines in other countries: United Kingdom, Australia, Canada, New Zealand
What to do now
- Call your vet or a pet poison line now.
- Note what was eaten, roughly how much, and when.
- Bring the food label or recipe if you have it.
- Watch for weakness, pale gums or red urine over the next several days.
Don't
- Don't make your dog vomit unless a vet tells you to.
- Don't wait for signs; they are often delayed.
Signs to watch for
- Vomiting
- Drooling
- Diarrhea
- Weakness or lethargy
- Pale gums
- Fast breathing or panting
- Red or dark urine
- Fainting or collapse
When signs appear: Stomach upset may come first; anemia signs often appear 3-5 days later
Why
Onions contain sulfur compounds that damage red blood cells, and powdered or dried forms are more concentrated. Signs are often delayed, so a dog can look fine at first.
Sources
- AKC: Can Dogs Eat Onions?
- VCA Animal Hospitals: Onion, Garlic, Chive, and Leek Toxicity in Dogs
- Merck Veterinary Manual: Garlic and Onion (Allium spp) Toxicosis in Animals
Guide reviewed 9 October 2026.
General information from the sources above, not a diagnosis. When in doubt, call your vet.