Why it is dangerous for cats
Onions contain sulphur compounds that damage red blood cells. The damaged cells break down and the cat becomes anaemic: it weakens, its gums turn pale, it breathes faster, and its urine may turn red or brown. Cats are more sensitive to these compounds than dogs.
Every form is dangerous: raw, boiled, fried and dried onion, onion powder, and the soups, sauces and baby food that contain it. How much onion does harm depends on the cat, so it cannot be judged at home. The damage builds up, and signs may only appear several days later.
What to watch out for
- Sulphur compounds damage red blood cells and cause anaemia.
- The cat can turn lethargic, its gums pale and its urine red or brown.
- Vomiting and diarrhoea can follow, and the cat may stop eating.
- Onion powder, soups, sauces and baby food are dangerous too, as are leeks and chives.
- Signs can appear only days later, so contact a vet straight away, say what your cat ate and when, and take the packaging with you.
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, plain cooked carrot is harmless to cats, but cats have no need for vegetables, so give it only as a small treat. Safe
- Pumpkin Yes, plain cooked pumpkin without sugar or spices is harmless to cats and fine as a small treat. Safe
- Chicken Yes, plain cooked chicken without bones, skin or seasoning is one of the best treats you can give a cat. Safe