My dog ate pizza with onion. Should I be worried? What symptoms?
Updated On September 23rd, 2025
Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 22 lbs
My dog got into my dominos supreme pizza and ate about 5 and a half slices, should I be worried? There was onion on the pizza
4 Answers
Most Helpful Answer
Published on April 24th, 2019
It is unlikely that there was enough onion present to cause a problem, but eating that much pizza will likely cause some gastroenteritis (inflammation of the stomach and intestines) which could lead to vomiting and diarrhea. He could also develop pancreatitis. If he starts vomiting, having diarrhea, isn't wanting to eat, or seems lethargic, please take him to your vet for treatment. In the meantime, withhold for at least 12 hours, then offer small amounts of. a bland diet such as boiled chicken and white rice for the next couple of days. Onions will cause oxidative damage to the red blood cells which can result in anemia. If the onions are going to be an issue, it will be a few days before you would see this, and generally would present as decreased appetite and lethargy. If those symptoms are noted, get him in to your vet for bloodwork. Again, I doubt there was enough onion present to be a problem. as generally its a relatively large amount that has to be ingested to cause a clinical problem. thanks for asking Petco Pet Education Center, formerly Petcoach!
33Pet Parents found this answer helpful
Related Answers from Veterinarians
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Published on June 3rd, 2017
Oh no, that's not good that Duncan at onions! Onions are toxic to dogs, but if he only ate a small side, he may not have eaten enough to cause problems. Without seeing him in person, however, I can't say for certain if he ate enough to cause problems or not. Onions cause anemia in dogs, and it can take up to a couple of days for symptoms to appear. If he ate the potato salad less than two hours ago, you can take him into a vet immediately to induce vomiting. Otherwise, monitor him for now. If he starts vomiting, becomes anorexic, the lethargy continues, and/or has diarrhea, then I would have him seen by a vet right away.
3Pet Parents found this answer helpful
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Published on January 31st, 2018
Onions are a rare cause of illness but are associated with anemia and destruction of red blood cells in some sensitive dogs. I would not be overly concerned about one single incident with such a small amount of onion, but would advise against regular feeding of onion or garlic products!. Monitor over the next 2 weeks for any tiredness or weakness but this is very unlikely
1Pet Parents found this answer helpful
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Published on October 14th, 2017
I am glad you were able to empty her stomach after vomiting. I would watch her closely for 24 hours for signs of GI upset (vomiting, decreased appetite, diarrhea), either from the hydrogen peroxide or from garlic oils. Garlic toxicity can cause problems with red blood cells, and this may take days or even weeks to show up. Symptoms can include lethargy, pale gums, increased breathing rate. If you have any concern at all, I would get her checked out with a vet to be safe. Here is some info on garlic and onion toxicity in dogs: http://www.petpoisonhelpline.com/poison/garlic/
1Pet Parents found this answer helpful
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