Can Dogs Eat Onions? Why You Should Avoid This Vegetable 

Can dogs eat onions? The answer to this question is a hard no. While there are many fruits and vegetables that your dog can eat, onions are not one of them. If your dog does ingest some onion, the consequences will likely be worse than tears. This is one veggie your pooch should avoid no matter what.  

Are Onions Bad for Dogs?

Onions won’t just give your dog bad breath — these vegetables contain a chemical compound called allyl propyl disulfide. It’s what gives onions their strong odor, and it’s also highly toxic to dogs of all kinds.³

When ingested, allyl propyl disulfide bonds to a dog’s red blood cells and causes oxidative damage. The cells become unable to carry oxygen through the bloodstream, leading to severe anemia. Not only that, but the afflicted blood cells are recognized by your dog’s immune system as invasive bodies. White blood cells attack the red ones, destroying them in a process known as hemolysis. Blood cells are destroyed faster than they can be replenished, resulting in a condition known as hemolytic anemia.

Can dogs eat cooked onions?

No. Allyl propyl disulfide is present in all parts of the onion and remains present even after they’ve been cooked. Leaves, flesh, and juice should all be avoided. Just 100 grams of onion per 20 kilograms of a dog’s weight can induce hemolytic anemia. That goes for all members of the onion family, including leeks and chives.

Processed onion powder is even worse. This common ingredient is found in everything from broth to baby food. It contains highly concentrated allyl propyl disulfide, so it takes even less to make your dog sick. Garlic and garlic powder also contain allyl propyl disulfide, in much higher concentrations, so add those to the list of banned substances for your dog.

Can cats eat onions?

Onions (and garlic) are even worse for cats than they are for dogs. Because cats are generally smaller than most dogs, it doesn’t take much to cause serious health problems.⁴

Symptoms of Onion Toxicity in Dogs

Despite our best efforts, there’s always the possibility of our curious pups finding their way to a bit of onion. Here’s how you can identify onion toxicity in your dog:

●      Vomiting, elevated heart rate, and panting: These are all indicative of onion poisoning, especially if they appear alongside symptoms of anemia.

●      Lethargy, weakness, fainting, and decreased appetite: These are symptoms associated with anemia which can be triggered by eating onions.

●      Pale gums and reddish urine: These are telltale hallmarks of hemolytic anemia, specifically.

What to Do if Your Dog Ate Onion

If you know or suspect your dog ingested any amount of onion, contact your veterinarian right away. Your vet will identify the symptoms and perform a blood test to diagnose hemolytic anemia. This condition can be recognized by the presence of Heinz bodies, which are clumps of hemoglobin attached to your dog’s red blood cells.⁵

Once diagnosed, your vet will likely treat onion poisoning in a number of ways. Depending on how recently your dog ingested onion, the vet may induce vomiting to prevent further allyl propyl disulfide absorption. Your dog may also need hospitalization and supportive care until the damaged red blood cells can be replaced with healthy ones. In extreme cases of onion poisoning, your dog might require a full blood transfusion.

A Layered Approach to Onion Safety

The best way to keep your pooch safe from onions is to keep all traces of this vegetable out of reach. If you grow onions in a garden, set up fences to make sure your dog doesn’t sample the produce. Wild onions can also pose a problem. Keep your dog on a leash and pay attention to what they’re sniffing while you’re out and about.

When it comes to the kitchen, onion safety is much simpler. Always chop and prepare onions out of reach of your dog, and be on the alert for any stray pieces. Thinking of giving your dog leftovers as a treat? Thoroughly read the ingredients. If it contains any amount of onion powder, the safest move is to keep it away from your dog.

Even after all these precautions, accidents still happen. You can prepare for the worst with a dog insurance policy from MetLife.¹ That way, if your dog does gobble up some onions, you can get them the medical attention they need without worrying about the bill.² Learn more here about what’s covered under a pet insurance policy.