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Are onions toxic to dogs

The essentials

  • Onions are toxic to dogs — They contain a toxic compound that breaks down red blood cells, leading to extreme anemia.
  • Watch for signs of onion toxicity — Symptoms include lethargy, panting, decreased appetite, vomiting, and elevated heart rate.
  • Onion toxicosis can be fatal — Clinical signs often show up within 24 hours and quickly worsen, so it’s vital to get your pup to a veterinarian ASAP.

What parts of onions are toxic to dogs?

All parts of an onion plant, whether raw or cooked, are toxic to dogs, including the flesh, leaves, juice, and any processed powders. The same goes for rest of the allium family (garlic, shallots, leeks, and chives).

Onions contain a toxic compound known as N-propyl disulfide. This substance causes your dog’s red blood cells to break down, leading to anemia.

Be careful of onion products, too

Onion powder is more toxic to dogs than a fresh onion and appears in a surprising number of foods. Check the ingredients before feeding your pup table scraps.

🚨Onion toxicity can be fatal. The moment you discover your dog has eaten onions or onion powder, it’s vital to get them to the vet ASAP.

Symptoms of onion toxicity in dogs

If you think your dog may have eaten an onion or onion powder, look out for:

  • Lethargy. Watch for a lack of interest in playtime, walks, and other activities your pup usually loves.
  • Weakness. Dogs may collapse, take longer to stand, be unsteady on their feet, or experience shaky limbs. 
  • Decreased appetite. Your pup might be uninterested in food and treats or refuse their favorite foods altogether.
  • Pale gums. Any gum discoloration that isn’t normal for your dog might indicate a problem.
  • Fainting. Watch your dog’s overall responsiveness and for any sudden losses of consciousness.
  • Reddish urine. Red or pink discoloration in your dog’s urine after exposure to onion is a sign that something is wrong.
  • Vomiting. Drooling and dry heaving are frequently seen before a dog begins vomiting, which can all be signs of a more serious health problem.
  • Elevated heart rate. Larger dogs have a slower heart rate (about 70 beats per minute), while smaller dogs have a faster heart rate (about 120 BPM). Dogs with noticeably rapid heart rates should be seen by a vet.
  • Panting. While normal for excited dogs, when combined with other symptoms, heavy panting could indicate a serious problem.

Diagnosing onion toxicity in dogs

If your dog is exhibiting any of the above symptoms, the best thing you can do is to get them to your vet as soon as possible. Your veterinarian will do bloodwork and diagnose your dog’s condition based on their symptoms and blood results. If your vet finds hemolytic anemia (the formation of Heinz bodies on a blood smear) after possible onion exposure, then all signs point toward onion toxicity.

👉 Certain Japanese dog breeds, including Akitas and Shiba Inus, have proven especially susceptible to onion toxicosis.

Treating onion toxicity in dogs

If your dog suffers from toxic effects after eating onions, they’ll need veterinary attention. When you take your pup to the vet, they may induce vomiting if the onions were eaten recently to try and remove the toxins. Or, they may give your dog activated charcoal to help absorb the toxins in their stomach. Intravenous fluids can help flush your dog’s bloodstream and rehydrate them if they’ve been vomiting. In extreme cases, your dog may need a blood transfusion or even supplemental oxygen.

Safe vegetables for dogs

While onions are toxic, there are plenty of healthy and safe vegetables for dogs . These include:

  • Broccoli. Broccoli is high in fiber and vitamin C and low in fat but is known to cause gas when given in large amounts. It’s best used as an occasional treat.
  • Brussel sprouts. Loaded with nutrients and antioxidants, Brussel sprouts are healthy but can also cause gas.
  • Carrots.  A great low-calorie snack that is high in fiber and beta-carotene (which produces vitamin A). Plus, they’re great for your dog’s teeth!
  • Celery. Full of vitamins A, B, and C, celery is also known to promote a healthy heart and fight cancer.
  • Green beans. High in fiber and low in calories, green beans are also full of healthy vitamins and minerals. When buying canned green beans, look for low-salt or no-salt options.
  • Peas. All types of peas are safe and healthy for dogs, including green peas, snow peas, sugar snap peas, and garden or English peas. They have several vitamins and minerals and are high in protein and fiber.

Frequently asked questions

How much onion is a toxic amount for dogs?

If your dog gets into onions, it only takes .05% of their body weight to be a toxic amount. That’s equal to one small onion for a medium-large dog.

How long does it take for onion toxicity in dogs?

Symptoms typically show up within 24 hours but can be delayed for up to seven days after the onion was ingested.

Why are onions harmful to dogs?

Onions contain N-propyl disulfide, a toxic compound that causes a breakdown of red blood cells, leading to anemia in dogs.

What happens  if dogs eat onions?

Dogs who eat onions can develop a condition called hemolytic anemia. This condition breaks down a dog’s red blood cells, leaving them without enough red blood cells to function properly. It can lead to limb weakness, fainting, vomiting, pale gums, decreased appetite, and more. Severe onion poisoning in dogs can be fatal.