My dog ate a sandwich with onion. Should I worry about onion toxicity?
Updated On September 23rd, 2025
Pet's info: Dog | Boxer | Female | 75 lbs
I have a 75lb boxer and she fot I to the trash and ate a sandwich that had some chopped up onion on it . Will she be ok ?
2 Answers
Most Helpful Answer
Published on August 2nd, 2020
Hello and thank you for contacting Petco Pet Education Center, formerly Petcoach. Onion in toxic to dogs but the toxic dose is fairly high. Sadie would have to eat more than a half of a large onion (or a whole normal size onion) to get into any trouble. She may show mild signs of stomach upset, like a bout of vomit or loose stools but there should not be any more concerning symptoms.
1Pet Parents found this answer helpful
Related Answers from Veterinarians
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Published on September 22nd, 2018
That's not good that Roxxi ate the sub with onion slices! Tomato isn't toxic to dogs, but onions are toxic. The toxic dose is typically 15-30 grams per kg of body weight. At 50lb, she is 22.72kg, and that means she would have to eat between 341-682g of onion to cause any toxic effects. A small amount of onion slices would likely not weigh that much, so I imagine she will be fine. I hope this helps!
3Pet Parents found this answer helpful
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