Green onions and scallions are the same species as the bulb onion, harvested young, so the toxic mechanism is identical. Both the green tops and the white base count, and signs of anemia can be delayed for days.
Call a vet or poison control now. Do not wait for symptoms.
ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661. A consultation fee may apply.
Educational reference. Not individualized veterinary advice.(more)
See this page's cited references for supporting information and our Sources page for the reference organizations we use. Citations do not imply that those organizations reviewed or endorsed DogSafe.
Part of our guide to Hidden Onion and Garlic in Everyday Dog Food Risks.
Read the general guidance and keep your dog's exposure details ready for a veterinary call. This checker cannot decide whether an exposure is safe.
Why Green Onions is dangerous
Green onions and scallions are the same species as the bulb onion, just harvested young, so the toxic mechanism is identical: they damage red blood cells and risk anemia. Both the green tops and the white base count. They are a common scatter-on garnish, which means dogs often get them from plates and takeaway containers rather than from a meal, and the effect is both cumulative and delayed.
Part of the Onion guide
For related dog-safety questions and product-by-product answers, see the complete onion guide.
Signs to watch for
Weakness, pale gums, dark urine, lethargy, vomiting, rapid breathing, reduced appetite
Related items
Check the exact item or ingredient before assuming two similar exposures carry the same risk.
What to do next
Estimate how much was eaten, call your vet with the amount, and watch for pale gums or dark urine over the next several days.
🚨Step-by-step: what to do in the first 10 minutes →Available 24/7. A consultation fee may apply.
Young onion is still onion
The assumption that scallions are a herb rather than an onion is the reason this page exists.
1. Tops and bulb both count
Scallions are Allium cepa or close relatives picked before the bulb swells, not a different, gentler plant. The green tops carry the same compounds as the white base, so scraping the garnish off a takeaway container does not make the rest safe if it has been sitting in the same sauce. How much allium is too much, by form →
FAQ
Toxic by weight, with the usual delay before signs appear. A stray ring off a plate is low-risk for a big dog; a handful, or the garnish off a whole takeaway meal, is worth a call.
A trace once in a large dog, usually monitor. More than that, call, because the effect is delayed and cumulative.
Any real amount, a small dog, a Japanese breed, repeat exposure, or any sign of weakness or dark urine.
- ASPCA Animal Poison Control Center, people foods to avoid feeding your pets (onions, garlic, chives)
- Pet Poison Helpline, onion and garlic toxicity
- Merck Veterinary Manual, Allium species toxicosis
- Merck Veterinary Manual: garlic and onion (Allium spp) toxicosis in animals
- Pet Poison Helpline: garlic
- Pet Poison Helpline: onion
- ASPCA Animal Poison Control: people foods to avoid feeding your pets
- Merck Veterinary Manual: food hazards