Also see Onion (plant).
Onion is toxic to both dogs and cats and should be kept well out of reach of all pets. Even small amounts can cause adverse reactions in some animals.
Onions, along with garlic, leeks and chives, contain sulphur compounds that damage red blood cells and cause anaemia. Raw, cooked, dried and powdered onion are all dangerous. Onion powder is concentrated, so watch for it in gravy, stock, soup, baby food and seasoned leftovers. Cats are more sensitive than dogs. In dogs, problems are consistently seen after eating onion weighing about 0.5% of body weight at once, which is roughly one medium onion for a 20 kg dog. Small amounts eaten over several days can also add up.
Early signs can include drooling, vomiting, diarrhoea and a sore belly. Signs of anaemia usually appear a few days later: weakness, tiredness, pale gums, fast breathing, a racing heart, and red or brown urine.
Call your vet, especially if your pet ate a lot or is a cat. If it happened within the last couple of hours, the vet may make your pet sick to limit how much is absorbed. Anaemia develops over several days, so your vet may want to repeat blood tests even if your pet seems fine at first. Severe cases can need a blood transfusion.
Data sourced from public ASPCA lists. For general guidance only. If you suspect your pet has ingested something harmful, contact your vet or an animal poison control center immediately. · Privacy Policy