Can Dogs Eat Onions? No—And Here’s What To Do If Your Dog Does

By: Lauren JoskowitzUpdated:

can dogs eat onion: whole and cut onions on pink background

Can Dogs Eat Onions? No—And Here’s What To Do If Your Dog Does

Onions are a culinary cornerstone in my kitchen. On a typical day, I sneak them into my breakfast, lunch and dinner. Because they’re not only tasty, they’re super healthy, too. But just because something is healthy for humans doesn’t mean it’s safe for pets. So, can dogs eat onions? Turns out, unlike other vegetables such as cucumbers, zucchini and peppers, onions can be very dangerous for dogs.

We spoke to a vet expert to peel back the layers of information when it comes to onions and our furry friends.

Expert input provided by Dr. Sarah J. Wooten, DVM, a veterinarian at Sheep Draw Veterinary Hospital in Greeley, Colorado.

Why Are Onions Unsafe for Dogs?

Certain compounds found in onions can cause toxicity or poisoning in dogs.

When consumed, these toxic compounds are absorbed into the bloodstream and cause your dog’s red blood cells to break down—a process known as hemolysis—which can result in a condition called hemolytic anemia.

Hemolytic anemia occurs when red blood cells are destroyed faster than your dog’s body can produce new ones, resulting in a low red blood cell count. Red blood cells are essential because they carry oxygen in the bloodstream. When this process is compromised, your dog may show symptoms such as weakness, lethargy, an elevated heart rate, or even collapse.

How Much and What Kind of Onions Are Bad for Dogs?

All onions are toxic for dogs, as are garlic and garlic powder, leeks, shallots, chives and scallions/green onions all of which are part of the onion/allium family.

And it doesn’t matter what form they’re in. Raw onions, cooked onions, dehydrated onions and powdered onions are all harmful and potentially toxic for our furry loved ones. Yep, even onion rings!

Will a small amount of onions hurt your dog? Would even just a piece of onion be a toxic amount? Well, it depends on the size of your dog and how much onion is consumed.

“If a German Shepherd eats one small bite of a dish that contains onion, they might be fine,” says Dr. Wooten. “But a Chihuahua would not be.”

Generally speaking, though, most pets who eat more than 0.5% of their body weight in onions end up with toxicity symptoms.

Here’s what that means for your dog, according to size:

Small dog (<10 pounds)
Medium-sized dog (<30 pounds)
Large dog (<60 pounds)
Small dog (<10 pounds)

1/10 of a medium-sized onion

Medium-sized dog (<30 pounds)

1/3 of a medium-sized onion

Large dog (<60 pounds)

2/3 of a medium-sized onion

Small dog (<10 pounds)

1/10 cup diced onion

Medium-sized dog (<30 pounds)

1/3 cup diced onion

Large dog (<60 pounds)

2/3 cup diced onion

Small dog (<10 pounds)

1/10 tbsp onion powder

Medium-sized dog (<30 pounds)

1/3 tbsp onion powder

Large dog (<60 pounds)

2/3 tbsp onion powder

What Will Happen to My Dog If They Eat Onions?

Again, it depends on your dog’s weight/size and how much is consumed, but symptoms of onion toxicity or poisoning can show immediately or take a couple of days to manifest.

Symptoms of onion toxicity or poisoning in dogs include:

  • Vomiting
  • Diarrhea
  • Weakness or fatigue
  • Pale gums
  • Loss of appetite
  • Jaundice (yellowing of skin or eyes)
  • Red or brown urine
  • Racing heart
  • Panting

And in severe cases, the ingestion of onions in any form can be fatal for dogs.

Uh, Oh—My Dog Ate Onions, What Do I Do?

If a dog consumes any amount of onion, pet parents should immediately seek veterinary care or call the Pet Poison Helpline at 800-213-6680.

When it comes to treatment, your vet may choose a variety of protocols, from inducing vomiting (if onions were eaten within one to two hours prior to the visit) to suggesting IV fluids or, in severe cases, blood transfusions.

They may also administer activated charcoal to help bind any remaining toxins in your dog’s digestive tract.

Your vet will likely continue to monitor your dog’s vitals—or suggest you do it from home—and may recommend hospitalization if further intensive care is needed.

How Do I Prevent My Dog From Eating Onions?

To prevent your dog from nibbling on onion, follow these tips:

  • Keep onions stored away: Store onions in a secure, airtight container and far out of reach from your pup. High shelves, cabinets or the fridge or freezer are safe options.
  • Have rules in the kitchen: Consider establishing pet-friendly kitchen rules that prevent your dog from hanging out in the kitchen when you’re cooking meals or preparing food.
  • Clean up messes immediately: If you spill onions on the kitchen floor, be sure to clean it up promptly. And avoid sharing human food that may contain onions in any form with your dog—no matter how hard they may beg you to lick the plate clean.

FAQs About Onions and Dogs

Dr. Wooten answers more frequently asked questions about onions and dogs.


Is onion powder safe to use in dog food or treats?

A:No, onions in all forms, including powdered, are toxic for dogs.


Can my dog eat cooked onions?

A:No, cooked onions still contain toxic compounds for dogs and should be avoided.


Can onions be used as natural remedies for dogs?

A:No, onions should never be used as natural remedies for dogs, as they are toxic to dogs and can cause serious health problems and even death.


Are there flavorful alternatives to onions that are safe to add to dog food and treats?

A:Sure! Parsley, basil, oregano and turmeric are all safe for dogs to consume in small amounts. Curious what other herbs and spices you can add to dog food and treats? Here’s a list of seasonings and herbs dogs can have.


Should I make my dog vomit if they eat onions?

A:No, never induce vomiting in your pet without consulting with a veterinarian first.


Are certain dog breeds more sensitive to onions than others?

A:Onions are harmful for dogs of all breeds and sizes, but Japanese breeds like Akitas and Shiba Inus have an inherited, non-fetal red blood cell defect called hyperkalemia, which makes them especially sensitive to onion toxicity.
Curious what veggies are actually safe (and even healthy!) for your dog to enjoy? Scroll through our list of vegetables dogs can eat—and, when in doubt, seek the advice of your vet or Connect With a Vet.


By: Lauren JoskowitzUpdated: