Last Updated: 16/09/2026
Can Dogs Eat Onions and Garlic?
Onions and garlic are toxic to dogs in every form, raw, cooked or powdered. Our vet explains the hidden risks in gravy, stock and leftovers.
Author: Dr Gillian Hill BVSc (Hons)
Reading Time: 4 minutes - short read
Made a roast with a tray of onions, or simmered a stock full of garlic? If your dog's snuck a taste of the gravy, the leftovers or the garlic bread, it's natural to wonder whether that's actually a problem, or just a bit of extra flavour they'll sleep off.
No, onions and garlic are toxic to dogs, and so are leeks and chives. This applies in every form, raw, cooked, powdered, dehydrated or as part of a dish like gravy or stock. These foods contain compounds that damage a dog's red blood cells and can lead to a type of anaemia called haemolytic anaemia. Even small amounts eaten regularly can add up and cause harm, so it's best to keep the whole onion family away from your dog altogether.
Can dogs eat onions or garlic?
No. Onions, garlic, leeks and chives are all part of the Allium family, and every part of the plant is toxic to dogs. They contain organosulphur compounds that damage red blood cells once digested, making the cells fragile and causing them to break down faster than your dog's body can replace them, a condition called haemolytic anaemia. Effects can start within 24 hours of a large dose, but the red blood cell damage typically peaks around 72 hours and haemolysis is often most obvious 3 to 5 days after eating, which is why symptoms don't always show up straight away.
The toxic dose of onions in dogs is 15-30 g/kg of body weight. Garlic is the more potent of the two, generally considered three to five times more toxic than onion gram for gram, so even a small amount matters. In clinic, owners are often surprised that the anaemia doesn't show up until days later, by which point they've long forgotten the meal that caused it.
Where do dogs actually get into onion and garlic?
The cases we see aren't usually a dog eating a raw onion out of the vegie crisper, they're a dog getting into a cooked food that has onion or garlic included. Onion and garlic are everyday kitchen staples, so the real risk hides in the dishes built around them: gravy, stock or bone broth, burgers, pasta sauce, quiche, soup, takeaway leftovers and garlic bread. These are often more concentrated in flavour than the raw ingredient, and they smell irresistible to a dog. Cooking doesn't neutralise the toxic compounds, so a cooked dish carries the same risk as raw.
Read more about toxic foods for dogs if you want the full list beyond onion and garlic.
Does a little bit matter?
Yes. A lick of gravy here, a corner of garlic bread there, none of these on their own might seem like much. But the effect on red blood cells can be cumulative, so repeated small exposures over time can add up. We see this most often in dogs who get a splash of gravy over their dinner most nights. It's worth keeping onion and garlic away from your dog consistently, rather than treating the odd taste as harmless.
Is garlic powder safe for dogs?
No. Dehydrating and powdering garlic concentrates the toxic compounds rather than diluting them, so a small sprinkle of garlic powder can pack a bigger punch than the same amount of fresh garlic. Watch for it in seasoning blends, gravy mixes, stock cubes and marinades, and check the label on any takeaway or leftovers before sharing them with your dog.
What are the signs of onion or garlic poisoning, and when do I call the vet?
Clinical signs of haemolytic anaemia can take a few days to appear as red blood cells break down, though you might see signs of digestive upset such as vomiting and diarrhoea earlier. Don't wait for symptoms if you know your dog's eaten a significant amount. Call your vet or an emergency vet straight away.
If your dog has eaten a very small amount as a once-off, watch for:
- Lethargy and weakness
- Pale or yellowish gums
- Vomiting and diarrhoea
- Loss of appetite
- Orange or dark brown urine (a sign red blood cells are breaking down)
- A faster than normal heart rate or breathing
Collapse is a medical emergency. Early treatment makes a real difference, so it's always worth a call even if your dog seems fine.
Are cats at risk too?
Yes, and cats are even more sensitive to onion and garlic than dogs, with much smaller amounts able to cause harm. In a multi-pet household, the same rule applies to everyone, keep the kitchen bench and the bin off limits, and be very cautious with any human foods offered to pets.
Onions, garlic, leeks and chives are toxic to dogs in every form, and the real danger usually isn't the raw vegetable, it's the gravy, stock and leftovers they end up in. The safest approach is to keep all of it away from your dog and reach for dog-safe treats instead when you want to give them a little something extra. You can check the wider list of human foods that are safe for pets before sharing anything else from your plate. If your dog does get into something onion or garlic based, call your vet, even if they seem okay for now.
FAQs
Articles recommended for you
Wondering what human foods are dangerous for dogs? Our expert vet explains the most common toxic foods found in your kitchen, including chocolate, grapes, xylitol, and onions. Learn why they are harmful and find safe alternatives to treat your dog.
Learn which human foods are safe or unsafe for your pets? Read more here.
Keep your pet safe this Easter. While we enjoy chocolate and hot cross buns, these treats are toxic to pets. Our vet details the top Easter dangers, including lilies and macadamias, and provides safe treat alternatives.
Keep your pet safe this Christmas! Many festive foods like ham, fatty offcuts, macadamias, grapes, and chocolate are toxic to pets. Our vets list the common dangers, the risks (like pancreatitis), and offer great, safe treat alternatives for your dog or cat.
Chocolate is a favourite treat for humans but a major hazard for hounds. Discover why theobromine is toxic to dogs, how to spot the symptoms of poisoning, and exactly what to do if your furry friend raids the pantry.
Watermelon for dogs: Safe or not? A comprehensive guide for you and your pet.
While those puppy dog eyes are hard to resist, not all cheese is created equal. Learn about the benefits of calcium and protein, the risks of high-fat dairy, and how to choose the safest, low-lactose options for your furry friend's snacks.
Can dogs eat grapes or raisins? The answer is a definite no. Both are highly toxic to dogs and can lead to life-threatening kidney failure. Even a small amount can be dangerous. Our vet guide explains the signs of toxicity and the urgent steps to take.
Wondering if blueberries are safe for dogs? Take a look at our guide for all the answers!
Yes - strawberries are a safe, low-sugar treat for dogs in moderation. Here's how to feed them safely, including a frozen treat idea and what to know if your dog is small, a puppy, or watching their weight.
Can dogs eat apples? Yes, in moderation. Our vet covers seed and core risks, choking hazards, green apples and apple products to avoid.
Take a read through our Vet-written guide for all the answers on milk for dogs!
History
Our experts continually monitor the health and wellness space and we update our articles when new information becomes available.
Wed 16 Sep 2026
Written by Dr Gillian Hill BVSc (Hons)Dr Gillian Hill BVSc (Hons)
Veterinarian
Dr. Gillian graduated from the University of Sydney in 2005 with a Bachelor of Veterinary Science. She worked in a number of small animal clinics, before joining the Pet Circle Vet team in 2020. Dr. Gillian has special interests in ultrasonography, surgery and behaviour. Her favourite part of being a vet is being an advocate for the animals. She loves helping owners to make the best, evidence-based decisions for their pets, and seeing the beautiful bond that people have with their fur-babies.
