Cat Onion & Garlic Toxicity Calculator — Heinz-Body Anemia Risk
Did your cat eat onion, garlic, leek or chive? Cats are 3-5× more sensitive than dogs to allium toxicity. Check the risk level and get immediate vet guidance.
Calculator
What to do
Avoid all allium foods. Monitor for 72 hours.
Symptoms to watch for
- Minimal at very low dose
Frequently Asked Questions
How much onion is toxic to a cat?
Cats are 3-5× more sensitive than dogs. Approximately 5 g/kg (0.18 oz per 2 lb) of onion causes Heinz-body anemia. For an 8 lb cat, that's ~18 g or about 1 small slice of raw onion. Garlic is 4-5× more toxic than onion by weight.
Why are onions and garlic toxic to cats?
All alliums (onion, garlic, leek, chive, shallot) contain organosulfur compounds (allyl sulfates, propyl disulfides) that damage feline red blood cell membranes, causing oxidative Heinz-body formation and hemolytic anemia. Cooking does NOT reduce toxicity.
What are symptoms of onion/garlic poisoning in cats?
Within hours: vomiting, diarrhea, loss of appetite. 1-4 days later: pale or yellow gums, weakness, rapid breathing, increased heart rate, red-tinged urine (hemoglobinuria). Severe cases may need blood transfusion.
What foods contain hidden onion/garlic?
Baby food, meat baby food (many brands), soups, broths, sauces, gravies, processed meats, pet food topping products, garlic powder, onion powder, pizza, Chinese food. Always check ingredient lists.
Is garlic safe in small amounts for cats?
No. Despite pet supplement marketing, there is NO proven safe dose of garlic for cats. Studies show even small daily amounts cause subclinical red cell damage that accumulates.
Sources & References
- [1]Allium Toxicity in Cats and Dogs — Merck Veterinary Manual
- [2]Onion and garlic toxicity in cats — VCA Animal Hospitals
- [3]
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