Petco Text Logo
Petco Pet Logo

  • Two Easy Ways to Start Earning Rewards!

My dog ate onion, now wheezing & diarrhea. Should I be concerned?

Updated On September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 5 months and 25 days old | 15 lbs

Hi - my dog may have eaten a tiny bit of onion (some fell onto the floor and we picked it up asap) yesterday. He seems like he is wheezing or short of breath when he gets excited when I come home. Today he pooped 3 times in an hour which isn't normal for him and the last two were very runny. Should I be concerned/are these related?

2 Answers

Most Helpful Answer

Image profile

Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on June 26th, 2017

A "tiny bit" would likely not cause the symptoms described. A 20lb dog would need to eat about a quarter cup of onions to develop a toxicity. Symptoms typically take several days to develop and may include oral irritation, drooling, GI upset, lethargy, rapid heart rate, panting, pale/blue gums, collapse, abdominal pain or weakness. Monitor him for worsening signs. Withhold food for 12-24 hours but allow small amounts of water or unflavored PediaLyte. Feed a bland diet in small frequent amounts until symptoms resolve then transition slowly to his regular diet. See your veterinarian if symptoms persist.

Vote icon

1Pet Parents found this answer helpful

Other Answers

  • Image profile

    Answered By Dr. Melanie, BVSc MS

    Veterinarian

    Published on

    It is concerning that Rio ate some onion and is now having symptoms of being ill. If eaten in large enough amounts, onions cause anemia in dogs but if he only ate a tiny bit, that shouldn't be enough to cause anemia. I would be suspecting more that his symptoms are unrelated and he could be developing a respiratory infection causing the wheezing, while the runny poop could be due to the small amount of onion or it could be due to a GI illness, eating something rotten, or intestinal worms. I would keep an eye on him for now, and if these symptoms continue over the next 12 hours, have him seen by a vet for a health check to be safe.

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
What fish dog food helps dry skin if my dog eats Science Diet?
Is your dog's dry skin a concern? A certified vet offers expert advice on finding the best fish-based dog food alternatives to Science Diet for essential oils.
Updated on February 04, 2026
Petco Pet Education Center
Food & Nutrition
What's the best way to feed my hamster when I'm going on a trip?
Planning a trip to Chicago and need to feed your Syrian hamster? A certified vet offers expert advice on feeding options for short and long trips, plus finding trusted pet sitters.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
Can chickens eat bell peppers daily and what about veggie salads?
Can your chickens eat bell peppers and salads? Veterinarian Dr. Elizabeth offers expert advice on safe feeding, frequency, and how fresh veggies boost vibrant yolks.
Updated on December 04, 2025
Petco Pet Education Center
Food & Nutrition
My newly adopted pet won't eat hay. What can I do to encourage it?
Adopted a pet not eating hay? Dr. Stafford, a certified vet, offers expert guidance on encouraging hay consumption, including adjusting pellets and trying fresh types.
Updated on December 04, 2025
Petco Pet Education Center
New Pet
Why is my new pet biting? Is she stressed or scared in her new home?
New pet biting? A Licensed Vet Tech shares expert advice on how to gently acclimate your new companion to their home, reduce stress, and build trust. Get guidance for a happy pet.
Updated on December 04, 2025
Petco Pet Education Center
Health & Wellbeing
My pet is breathing hard, not eating, and lethargic. What's wrong?
Is your rat breathing heavily, won't eat, and has no energy? A Licensed Vet Tech explains potential causes like infection and age, urging a vet visit for diagnosis.
Updated on December 04, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored