Dog Onion Toxicity Calculator
Assess the risk if your dog ate onion, garlic, or chives
Dog Weight (lbs)
What Was Eaten?
Amount Eaten (grams)
Why Are Onions Toxic to Dogs?
Onions, garlic, leeks, and chives belong to the Allium family and contain thiosulfates — compounds that damage dogs’ red blood cells, leading to hemolytic anemia. Unlike humans, dogs cannot adequately metabolize these compounds. All forms are toxic: raw, cooked, dried, and powdered. Garlic powder is approximately 5-8x more concentrated than raw garlic.
Allium Toxicity Reference
| Food | Relative Toxicity | Toxic Dose |
|---|---|---|
| Raw onion | Baseline (1x) | >5-10 g/kg = high risk |
| Garlic (raw) | 5x more toxic | >1-2 g/kg = high risk |
| Onion powder | 5x more concentrated | Even small amounts = risk |
| Garlic powder | 25x more concentrated | Fractions of a gram = risk |
FAQs
Can dogs eat food cooked with onions?
No — cooking does not destroy the thiosulfates. Onion soup, onion rings, and any food cooked with onion or garlic is still toxic to dogs. Even small amounts consumed regularly can cause cumulative toxicity.
What are the symptoms of onion poisoning in dogs?
Symptoms may be delayed 1-5 days: lethargy, weakness, pale or yellowish gums, reduced appetite, elevated heart rate, collapse. These are signs of hemolytic anemia. Any suspected onion ingestion warrants immediate vet contact before symptoms appear.
Conclusion
If your dog ate onion or garlic, call your vet immediately — do not wait for symptoms. For routine dog health, use our calorie calculator and food calculator.