Cat Onion Toxicity Calculator
You must note: This calculator does not replace professional medical advice and should not be used as the sole basis for clinical decisions. If you have any concerns, please contact your veterinarian immediately.
Input
- Cat’s Weight (kg): The current body weight of your cat in kilograms.
- Onion Amount Ingested (g): Estimated total weight of onion consumed — raw, cooked, or powdered.
Output
- Onion Dose per Kilogram (g/kg): Calculated as total onion ingested divided by the cat’s body weight.
- Toxicity Risk Level: Categorized as Low, Moderate, High, or Severe.
- Veterinary Recommendation: Suggested action based on estimated risk level.
Calculation Method
The toxicity dose is calculated by dividing the total amount of onion consumed (in grams) by the cat’s body weight (in kilograms). Cats are more sensitive than dogs to the toxic compounds in onions, specifically N-propyl disulfide and other thiosulfates, which can lead to oxidative damage and hemolytic anemia.
Veterinary toxicology references suggest the following thresholds for toxicity in cats:
- 2.5–7.5 g/kg: Potential toxicity
- 7.5–15 g/kg: Likely toxic
- >=15 g/kg: High risk of hemolytic anemia and potentially fatal consequences
Risk Levels and Veterinary Guidance
| Onion Dose (g/kg) | Risk Level | Veterinary Recommendation |
|---|---|---|
| < 2.5 | Low | Monitor your cat. Contact a vet if symptoms appear. |
| 2.5 – 7.4 | Moderate | Contact your veterinarian for evaluation and advice. |
| 7.5 – 14.9 | High | Likely toxic. Veterinary examination is strongly recommended. |
| ≥ 15 | Severe | Emergency! Seek immediate veterinary care. |
Common Symptoms of Onion Toxicity in Cats
- Vomiting or diarrhea
- Fatigue and weakness
- Pale or yellow gums
- Rapid breathing or increased heart rate
- Dark or reddish-brown urine
- Loss of appetite or lethargy
Symptoms may develop over 12–72 hours and worsen progressively as red blood cells are destroyed.
When to Contact a Veterinarian
- If the onion dose exceeds 2.5 g/kg, especially for kittens or senior cats.
- If any of the listed clinical symptoms are observed.
- If the onion was consumed with other toxic ingredients (e.g., garlic, chives, seasonings).
- Even small amounts may be dangerous for cats with underlying health conditions.
Disclaimer
This calculator is intended for informational and educational use only. Cats are extremely sensitive to onion toxicity, and toxic reactions can vary widely depending on individual health, age, and exposure history. When in doubt, always consult a licensed veterinary professional.