Can Dogs Eat Onion?
No. Onion is toxic to dogs. It contains N-propyl disulfide (Allium) and oxidative damage to red blood cells (Heinz body anemia). There is no amount we can call safe, so it should stay off the menu. If your dog has already eaten some, contact your veterinarian or a pet poison hotline right away.
ASPCA Animal Poison Control (US): (888) 426-4435 (a fee may apply) · Pet Poison Helpline (US/CA): (855) 764-7661 (a fee applies)
Why it is toxic
N-propyl disulfide (Allium) · oxidative damage to red blood cells (Heinz body anemia)
Which parts are the problem?
Dose & exposure rules
Toxicosis reported at about 0.5% of body weight in onion; repeated small amounts accumulate
If it must be on the menu: safe preparation
None in any form
Symptoms to watch for
vomitingdiarrhealethargypale gumsred or brown urinebreathing effort
Anemia often delayed 1-5 days
What to do now
Vet visit even if the dog seems fine — damage is cumulative
FAQ
How much onion can a dog eat?
Toxicosis reported at about 0.5% of body weight in onion; repeated small amounts accumulate
What are the signs of onion problems in dogs?
Watch for: vomiting; diarrhea; lethargy; pale gums; red or brown urine; breathing effort. Anemia often delayed 1-5 days
What should I do if my dog ate onion?
Vet visit even if the dog seems fine — damage is cumulative
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