Why it is dangerous for dogs
Onions contain sulphur compounds that damage a dog's red blood cells. The damaged cells break down faster than the body can replace them, which can lead to anaemia. Raw, cooked, fried and dried onion, onion powder, leeks and chives are all dangerous.
The amount that causes harm differs from dog to dog and cannot be judged at home. The damage builds up, and signs may only appear a few days later.
If your dog ate onion or food containing it, contact a vet or an emergency clinic straight away, even if your dog seems well. Tell them what was eaten and when, and take the packaging with you.
What to watch out for
- Red blood cells are damaged and anaemia can develop.
- The dog becomes weak, dull and tires quickly.
- The gums can turn pale, breathing can speed up and the urine can turn reddish or brown.
- Vomiting, diarrhoea, belly pain and loss of appetite can follow.
- Onion is found in soups, sauces, mince dishes, pizza and baby food, so a dog can eat it by accident.
What it can cause
Signs that can appear after eating it. Each page explains what to look out for and when to hurry to a vet.
What to give instead
Foods that are safer to give.
- Carrots Yes, carrots are fine for dogs: raw or cooked, unseasoned and cut into pieces, they make a crunchy, low-calorie treat. Safe
- Cucumbers Yes, fresh cucumber is fine for dogs: it is mostly water and low in calories, but do not give pickled cucumbers. Safe
- Pumpkin Yes, plain cooked pumpkin flesh without sugar or spices is fine for dogs, but not the skin, the stem or pumpkin pie filling. Safe
- Courgettes Yes, courgettes are fine for dogs: raw or cooked, without oil, salt or spices, they make a light, low-calorie treat. Safe