Can dogs eat leeks?
Updated 7 August 2026
No. Leeks are members of the allium family, and Pet Poison Helpline lists them as toxic to dogs in the same way as onions, garlic and chives, whether raw, cooked or dried. The compounds damage red blood cells, and the worst signs often take days to appear. Anything more than a trace is worth a call to your vet.
If your dog has eaten leek
Ring your vet if your dog has eaten leek in any real quantity, whether raw, cooked or as part of a dish such as soup or pie, and keep any packaging or a note of the recipe if you have it. Do not wait for symptoms, since anaemia often shows days after the leek was eaten, when treatment is harder. Out of hours, call Vets Now or the Animal PoisonLine on 01202 509000.
The detail
Leeks belong to the allium genus alongside onions, garlic, chives and shallots, and the MSD Veterinary Manual names leeks specifically, along with the other three, as sources of the organosulphur compounds behind allium toxicosis. Those compounds cause oxidative damage to a dog's red blood cells, and VCA Animal Hospitals explains that this leads to Heinz body formation and, eventually, haemolytic anaemia.
The damage builds quietly rather than showing straight away. The MSD Veterinary Manual describes the process unfolding over days: oxidative damage begins within 24 hours, methemoglobin levels peak around 72 hours, and red blood cell breakdown typically follows three to five days after a dog has eaten leek.
Cooking makes no difference to the toxin. PDSA is specific that leeks are toxic whether raw, cooked or dried, which rules out the common assumption that a leek softened in a soup or stew is any safer than a raw one.
VCA notes that among the four common allium vegetables, garlic is the most toxic weight for weight. That does not make leek a safer choice; it is still fully toxic, and there is no dose of leek considered a safe deliberate treat for a dog.
Risk by form
| Raw leek | ToxicSame organosulphur compounds as onion and garlic |
| Cooked leek (soup, stew, pie) | ToxicPDSA: cooking does not remove the toxin |
| Dried or powdered leek | ToxicConcentrated, the same as onion and garlic powder |
| Leek compared with garlic | VCA rates garlic the most toxic of the allium groupLeek is still fully toxic, not a safer alternative |
| Leek and potato soup | Toxic. Treat by estimated leek contentThe potato itself is not the problem |
Cooked leek in soups and stews
Leek and potato soup, leek gratin, and a chicken and leek pie are all common in UK kitchens, and every one of them carries the same toxin as a raw leek. PDSA is explicit that leeks are toxic whether raw, cooked or dried, so a splash of leftover soup is not a safer version of the vegetable.
This is how most dogs actually meet leek: not raw from the vegetable rack, but as a spoonful of dinner or a lick of a bowl left on the floor. Treat a bowl of leek soup the same way you would a raw leek, and keep dishes containing it well away from a dog that begs at the table.
Leek and potato soup specifically
A blended leek and potato soup hides the leek completely, which makes it easy to underestimate how much a dog has actually eaten if a bowl gets knocked over or licked clean. Plain cooked potato is fine for dogs, so the leek is the only ingredient doing the damage here.
If your dog has had a meaningful amount of leek and potato soup, ring your vet with an estimate of how much of the bowl went, since the leek content is impossible to judge by eye once it is blended in.
Raw leek and the vegetable patch
A dog that digs up and chews raw leeks in a vegetable patch has eaten the same toxin as one raiding a kitchen. VCA lists Allium porrum, the leek, specifically among the domesticated allium species implicated in dog poisonings, alongside onion, garlic and chive.
Fence off any bed growing leeks, onions or garlic if your dog is a known digger, and clear trimmings and outer leek leaves into a bin your dog cannot reach rather than the compost heap.
Leek compared with onion and garlic
Leek, onion, garlic and chive share the same toxic mechanism, and VCA states garlic is the most toxic of the four weight for weight. That comparison is about relative potency, not about leek being safe; leek in any real quantity is still a genuine poisoning risk.
There is no dose of leek that counts as a deliberate treat, in the way a pea-sized piece of cheese might be for a different food. If a recipe calls for leek, keep the dog's portion of the same meal leek-free rather than trying to work out a safe amount.
How much leek is dangerous?
There is no separately published toxic dose for leek the way there is for onion, since research has focused on onion and garlic as the most commonly eaten species. The safest approach is to treat any real quantity of leek the same way you would treat onion, and a trace amount, a lick of a soup bowl, as something to watch rather than panic over.
The oxidative damage behind allium poisoning does not reset between meals, so repeated small exposures can add up over time. A dog fed leek-containing leftovers regularly is a bigger concern than a single incident.
Signs to watch for
- Vomiting or diarrhoea in the first day
- Pale gums, weakness or tiring quickly on walks a few days later
- Red or brown-tinged urine
- Fast breathing or a racing heart
Common questions
Can dogs eat leek and potato soup?
No. PDSA is clear that leeks are toxic whether raw, cooked or dried, and blending the leek into a soup does not remove the toxin, it just makes it harder to judge how much your dog has actually eaten.
My dog ate a small piece of raw leek. Should I worry?
A trace is unlikely to cause serious harm, but it is still worth mentioning to your vet, since anaemia from allium poisoning often takes a few days to show. Watch for vomiting, pale gums or unusual tiredness over the following days.
Are leeks as dangerous as onions for dogs?
They share the same toxic mechanism and are both fully toxic, though VCA Animal Hospitals rates garlic as the most potent of the group. Leek is not a safer substitute for onion in any dog-friendly recipe.
Does cooking leek make it safe for dogs?
No. PDSA states plainly that leeks are toxic raw, cooked or dried, so a softened leek in a stew carries the same risk as a raw one.
How long after eating leek would my dog show symptoms?
The MSD Veterinary Manual describes red blood cell breakdown typically happening three to five days after ingestion, with anaemia symptoms often appearing in that window rather than immediately. Early signs such as vomiting or a reduced appetite can appear within the first day.
Can dogs eat the green tops of leeks?
No. Every part of the plant carries the same allium compounds, so the green leaves are just as toxic as the white base.