# dogs and onions **URL:** \ **Category:** Factual Questions\ **Created:** [November 4, 2001, 10:00pm UTC](https://boards.straightdope.com/t/dogs-and-onions/91476 "2001-11-04T22:00:59Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![wrongz](https://avatars.discourse-cdn.com/v4/letter/w/3ab097/32.png) [@wrongz](https://boards.straightdope.com/u/wrongz)\ **Post date:** [November 4, 2001, 10:00pm UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/1 "2001-11-04T22:00:59Z")
We all know chocolate is bad for dogs and aspirin is bad for cats, but lately I was told onions are bad for dogs, also. Any truth in this? Wrongz ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [November 4, 2001, 10:11pm UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/2 "2001-11-04T22:11:55Z")
True. Onions can induce [anaemia](http://www.universaldogs.com/medical/firstaid/onionpsn.htm) in both dogs and cats. > [@](#): > > Onions cause oxidative damage to hemoglobin, resulting in Heinz bodies. Cats are predisposed to this damage due to their hemoglobin structure. These cells then undergo accleerated destruction through either intravascular fragmentation or extravascular phagocytosis by the spleen. Signs include depression, hemoglobinemia, hemoglobinuria, and icterus. Diagnosis is made by observation of the dark blue spots on the RBC membranes (new methylene blue stain). Treatment is directed at removal of the onions (emesis if it is a recent ingestion). Blood transfusions may be given if indicated. (from [ColState](http://www.cvmbs.colostate.edu/ccu/pearlindivweb.cfm?questionnumber=221)) ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [November 4, 2001, 10:18pm UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/3 "2001-11-04T22:18:11Z")
> [@](#): > > Onions cause oxidative damage to hemoglobin, resulting in Heinz bodies Does anyone see the irony of onions in/on your dog causing “Heinz bodies?” Sorry for the hijack. And the poor humor. ---
**Author:** ![reprise](https://avatars.discourse-cdn.com/v4/letter/r/ea666f/32.png) [@reprise](https://boards.straightdope.com/u/reprise)\ **Post date:** [November 4, 2001, 10:24pm UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/4 "2001-11-04T22:24:26Z")
> [@](#): > > Does anyone see the irony of onions in/on your dog causing “Heinz bodies?” Sorry for the hijack. And the poor humor. Even more ironic as one of the sources of onion toxicity is people feeding their sick dogs and cats [baby food](http://www.tsev.com/pets/oct99.html). > [@](#): > > Another thing we see quite often is when small dogs or cats are ill the owner may try to get them to eat baby food. Make sure you look at the ingredient list to see if it has onion powder in it. We have seen sick pets get sicker (especially cats) by feeding food with onion powder. ---
**Author:** ![wrongz](https://avatars.discourse-cdn.com/v4/letter/w/3ab097/32.png) [@wrongz](https://boards.straightdope.com/u/wrongz)\ **Post date:** [November 5, 2001, 4:02am UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/5 "2001-11-05T04:02:19Z")
Thanks for the prompt and comprehensive response. Now something else occurred to me-is garlic in the onion family and when we give garlic to dogs and cats for flea control are their litle blood cells in danger? Thanx again, Wrongz ---
**Author:** ![whistlepig](https://avatars.discourse-cdn.com/v4/letter/w/73ab20/32.png) [@whistlepig](https://boards.straightdope.com/u/whistlepig)\ **Post date:** [November 5, 2001, 4:46am UTC](https://boards.straightdope.com/t/dogs-and-onions/91476/6 "2001-11-05T04:46:20Z")
If you feed a dog onions, it cant sneeze with it’s eyes open. That’s what I’ve always heard.