How to Calculate Onion Toxicity for Dogs

To calculate the onion toxicity for dogs, you need to know your dog's weight and the amount of onion consumed. The formula is:

Toxic Dose (g) = Your Dog's Weight (kg) × 2.5

Serious toxicity occurs when the consumed amount is twice the toxic dose.

Definitions:

• Toxic Dose: The amount of onion (in grams) that can cause toxicity in your dog.
• Serious Toxicity: Twice the toxic dose, which can lead to severe health issues.

Use the form above to input the values, and the calculator will determine if the consumed amount is toxic.

Are Onions Bad for Dogs?

To sum it up — YES, they are.

Onions, garlic, leek, and chives all contain a substance called N-propyl disulfide, a toxin characteristic for the allium plants that give them their specific, spicy taste.

N-propyl disulfide can easily break down the red cells in your dog's blood, causing vomiting, severe anemia, or even death. The dogs are not allergic to onions; these plants act just like a simple poison.

How much of an onion is toxic to a dog?

It is estimated that even the equivalent of 0.5% of your dog's weight, given in onions, may cause severe toxemia.

It all means that the toxic dose for a 10 kg (22 lb) dog amounts to 50 grams (1.8 oz), a mass equal to that of 1/3 of a medium onion.

The effects of consuming such an amount may include altered pet behavior and severe anemia. Remember, these signs and symptoms might be life-threatening.

❗ If your dog ate some onions, and you're unsure about the specific amount — don't hesitate to look for professional help.

Contact your vet if you are in doubt.

What happens if a dog eats onions?

When a dog eats onions, the toxin (N-propyl disulfide) enters its body and cannot be broken into smaller particles; the substance further blocks the enzymes in your dog's red blood cells, causing hemolysis, and in turn, their death. The blood cannot carry enough oxygen to the vital organs without sufficient red blood cells.

Since we don't know exactly how much of an onion is toxic to a dog, and your dog in particular, it is always better to be on the safe side!

What are the symptoms of onion poisoning in dogs?

• High heart rate
• Decreased appetite
• Panting
• Fainting
• Vomiting
• Breakdown of red blood cells (hemolytic anemia, Heinz body anemia)
• Blood in the urine (red/pink urine)
• Yellow eyes

Onion poisoning may result in death.

What should I do if I know my dog ate onions?

1. Contact your vet.
2. The professionals will treat and monitor your dog. The treatment may include intravenous fluids, oxygen support, or blood transfusions.

If you cannot reach a professional veterinarian service, call the pet poison control hotline. In such a case, they may have to guide you through inducing vomiting in your dog at home using a substance such as the 3-percent hydrogen peroxide solution.