
Welcome to “Can My Dog Eat That?,” our series that answers some obvious (and not-so-obvious) questions about what your dog can and can’t safely eat. You can view some of the previous foods we’ve looked at in our “Can my dog eat that?” guide. Today we answer the question “Can dogs eat onions?” Read on!
For a vegetable that makes you cry, onions sure are used a lot in our food. Raw, cooked or powdered, this versatile ingredient adds flavor to many a dish. But in the canine world, onions are a big no-no. Find out why you shouldn’t let dogs eat onions.
Can Dogs Eat Onions?
No! All parts of the onion plant are harmful, including the bulb, leaves and juices. It’s important to keep your dog away from any onions growing in your garden as well as wild onions you may come across while hiking. Onion powder is also toxic. It doesn’t matter if dogs eat cooked onions or raw onions, because cooking doesn’t reduce their toxicity.
Which Onions Are Toxic to Dogs?
If you’re wondering “Can dogs eat green onions but not yellow onions,” the answer is no. Onions are part of the Allium family, which includes shallots, green onions (also called scallions or spring onions), leeks, chives and garlic, and all of them are off limits. All plants in the Allium family contain disulfides and thiosulphates, which are toxic when ingested by dogs (and cats). So, as well as avoiding the Alliums listed above, it’s important that dogs don’t eat any other kind of onion, including sweet onions, red onions, yellow onions and green onions.
Why Are Onions Bad for Dogs?
If dogs eat a small amount of onion, they can experience vomiting and diarrhea soon after. When most dogs eat toxic amounts of onion, their red blood cells can become fragile and break down, causing anemia — a decrease in the number of circulating red blood cells. Because red blood cells transport oxygen from the lungs to tissues all over the body, the most common signs of anemia are:
- Lethargy (decreased activity)
- Exercise intolerance (they can’t exercise as long as usual)
- Decreased appetite
- Pale gums and mucous membranes
- Reddish-brown-colored urine
Anemia symptoms can take a few days to appear. In later stages of anemia, dogs may experience weakness and labored breathing. Severe cases of onion toxicity can be fatal.
Help! My Dog Has Eaten Onions
If you know or even suspect that your dog has eaten onions, onion powder or any other member of the Allium family, immediately call your veterinarian or an after-hours emergency clinic, or one of the two animal poison control centers in North America:
- ASPCA Animal Poison Control Center (1-888-426-4435)
- Pet Poison Helpline (1-855-764-7661)
It’s important that you don’t wait for symptoms to appear before seeking veterinary care. Try to estimate how much onion your dog ate so your vet can assess the risk of onion toxicity. If you’re able to get your dog to a veterinarian quickly, they may be able to induce vomiting to stop the onion from being digested. Do not induce vomiting at home unless your veterinarian has told you to do so.
Treatment of Onion Toxicity in Dogs
Treatment of onion toxicity usually requires supportive treatment and hospitalization. Anemia can be quickly diagnosed by checking the dog’s packed cell volume, which indicates the percentage of red blood cells compared to fluid in whole blood. If a dog’s packed cell volume is lower than the normal range, anemia is diagnosed. In severe cases of anemia, the dog may require a blood transfusion and long-term treatment.
Will a Small Amount of Onions Hurt My Dog?
The severity of onion poisoning in dogs depends on their body weight and how much onion they ate. The toxic amount of onion is generally recognized as approximately 0.5% of the dog’s body weight. So a 10-pound dog would potentially only need to eat 0.8 oz of onion to cause toxic effects on their red blood cells. At the other end of the scale, a 100-pound dog could potentially eat up to 8 ounces (or half a pound) of onions before their red blood cells are affected. To put that into perspective, a medium onion is around 8 ounces.
However, there are many contributing factors that can make dogs more susceptible to onion toxicity, including their breed and any preexisting health conditions. Japanese breeds like akitas, shiba inus and Japanese chins are known to be more susceptible to onion toxicity.
How Much Onion Can Dogs Eat? None!
Cooked onion, onion powder, onion casserole and every other type of onion are toxic to dogs. Just how much onion needs to be consumed to affect a dog’s red blood cells depends on the dog’s weight, breed and health. So, just like spicy food and grapes, it’s best to avoid giving dogs onions at all — stick to dog food or a healthy treat instead.
You can help prevent onion poisoning by making sure that onions are stored in a safe place your dog can’t get into. If you’re cooking with onion, make sure you throw away the outer layers and scraps immediately. And, of course, don’t feed your dog any food that contains onions or onion powder. Watch out for sneaky dogs swiping onion-containing food off the counter, too.
