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My 12lb dog ate onion strips and is throwing up. What now?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 3 years and 6 months old | 11 lbs

My 12 lb dog ate 2-3 raw onion strips from a burger. He vomited everything in his stomach out a couple hours after, and about 12 hours later, after not feeding him to avoid upsetting his stomach, he vomited again but it was all bile. He otherwise seems to be fine behavior-wise, doesn't have diarrhea so far, or show any signs of red flags. Is there anything else I should do besides keeping an eye on him for the next couple days? What should I be in the lookout for? Thanks!

3 Answers

Most Helpful Answer

Answered By Lindsey Edwards MVB, BSc, IVCA

Veterinarian

Published on May 18th, 2019

Such a small amount of onion is unlikely to cause any toxic effect (linked to anemia and weakness after a few days) - it may be hamburger meat or other rich food which has triggered the vomiting. I would recommend giving oral rehydration fluids (pedialyte) and feeding small but frequent meals of a very low fat, bland diet such as boiled skinless chicken, brown rice and canned pumpkin (or canned specialist intestinal low fat diet). If symptoms persist a full vet check would be required

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Rodrigo Roca, DVM
Veterinarian
Published on July 20th, 2018
Hello, its likely that the onion in the broth was not sufficient to cause toxicity. Onion toxicity typically occurs in dogs that eat a large amount of onion and will cause anemia. Signs of anemia due to toxicity may include pale gums, panting, lethargy, labored breathing, and collapse. If any of these are noted, your puppy should be seen immediately.

I am most concerned that the vomiting is likely secondary from the recent diet changes. You can offer him a bland diet of plain white rice, skinless and boneless chicken, and low fat cottage cheese for the next 3 days. If he is doing better, you may then encourage that he eats puppy food over cooked food. This is to ensure that your puppy has all of the essential nutrients he needs for his growing phase. Most commercial puppy foods are balances to support this stage of life.

If your puppy is not improving on a bland diet, then she should be evaluated by a veterinarian as other things could be causing her signs. This includes any infection with a virus or parasite. Hope this helps and best of luck.
1Pet Parents found this answer helpful
Answered By Dr. Melanie, BVSc MS
Veterinarian
Published on December 4th, 2019
Onions cause anemia if eaten in big enough amounts, but a few little slices shouldn't cause that. It may have upset Lucia's stomach. In the morning, feed her a bland diet of boiled white meat chicken (no bones) and white rice in small amounts several times a day for a couple of days. Then slowly add back in her normal diet. If she refuses to eat the bland diet, she vomits the bland diet, develops diarrhea, stops drinking water, starts vomiting water, or becomes very lethargic, she will need to see a vet right away.
1Pet Parents found this answer helpful

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