Calculadora de Toxicidade de Cebola para Cães
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
tóxico se > 5 g/kg (0,5% do peso)
About this calculator
The Onion Toxicity Calculator for Dogs determines if the amount of onion ingested by a dog poses a risk of poisoning. Onions contain sulfur compounds that damage dogs' red blood cells, potentially causing hemolytic anemia. The toxic dose is greater than 0.5% of the dog's body weight, i.e., 5 grams of onion per kilogram of weight. All forms of onion (raw, cooked, powdered, dehydrated) are dangerous.
The calculation is simple: enter the dog's weight in kilograms and the amount of onion ingested in grams. The tool compares the ingested amount to the toxic threshold (5 g/kg). If the amount exceeds this limit, a risk alert is triggered. Remember that even small repeated amounts can accumulate toxicity.
Use this calculator whenever you suspect your dog has eaten onion, whether a discarded piece, food scraps, or seasoned dishes. Common cases include ingestion of pizza, sauces, soups, or onion-flavored treats. The calculation helps decide whether urgent veterinary care is needed.
Important precautions: toxicity varies among dogs, but the 5 g/kg rule is a safe reference. Breeds like Akita and Shiba Inu are more sensitive. Additionally, onion powder is more concentrated, 1 teaspoon equals about 5 g of fresh onion. If in doubt, always consult a veterinarian, as symptoms may take hours or days to appear.
Frequently asked questions
My dog ate onion but I don't know how much. Should I still use the calculator?
Yes, try to estimate the amount. If unsure, assume the worst and seek veterinary help immediately.
Is cooked onion less toxic than raw onion?
No. Cooking does not eliminate the toxic compounds. All forms of onion pose the same risk.
How long does it take for onion poisoning symptoms to appear?
Symptoms can appear from a few hours up to 3 days after ingestion. Watch for vomiting, diarrhea, lethargy, and dark urine.
My dog ate a small piece of onion. Can I still use the calculator?
Yes, enter the dog's weight and estimated amount. Even small amounts can be dangerous for small dogs.
Does the calculator replace a veterinary consultation?
No. The calculator is a screening tool. If you suspect poisoning, take your dog to the vet.