If your dog is shaking, having a seizure, collapsing or breathing strangely, skip the reading and go to an emergency vet now. This calculator is for estimating risk. It can’t examine your dog.
Why chocolate is dangerous for dogs
Chocolate contains theobromine and a smaller amount of caffeine. People break these down in a few hours. Dogs take much longer, so the chemicals build up and overstimulate the heart and nervous system. That’s why a square of chocolate that does nothing to you can make a small dog seriously ill.
The darker and more bitter the chocolate, the more theobromine it has. White chocolate barely has any. Baking chocolate and cocoa powder are the real problems. An ounce of cocoa powder carries more than twelve times the dose of an ounce of milk chocolate.
How much chocolate is toxic to a dog?
Vets measure the dose in milligrams of theobromine and caffeine per kilogram of the dog’s body weight. The Merck Veterinary Manual gives these thresholds:
- About 20 mg/kg: mild signs like vomiting, diarrhea and extra thirst
- 40–50 mg/kg: effects on the heart, such as a racing or irregular heartbeat
- 60 mg/kg and above: tremors and seizures
Here’s how much each type contains, so you can see why the type matters so much:
| Chocolate | mg per ounce | mg per gram |
|---|---|---|
| White chocolate | 1.1 | 0.04 |
| Milk chocolate | 64 | 2.3 |
| Dark or semisweet | 150–160 | 5.3–5.6 |
| Cocoa bean mulch | 255 | 9 |
| Unsweetened baking | 440 | 15.5 |
| Dry cocoa powder | 807 | 28.5 |
For dark chocolate we use the higher end of the range. If your bar is 70% cacao or more, it likely sits between dark and baking chocolate. To be safe, run it as baking chocolate and see how the result changes.
An example: a 30 lb dog (about 13.6 kg) eats a 3.5 oz bar of dark chocolate. That’s about 99 g × 5.6 mg = 555 mg, or roughly 41 mg/kg. That’s in the range where heart effects are possible, so it’s a call-the-vet-now situation even if the dog seems fine.
Symptoms and when they start
Signs usually show up within 6 to 12 hours, which is why a dog that looks fine an hour after the theft isn’t in the clear. Watch for:
- Vomiting, diarrhea and drinking more than usual
- Restlessness, panting and pacing
- A fast or irregular heartbeat
- Muscle twitching, stiffness or wobbling
- Seizures, in severe cases
In bad cases symptoms can last up to three days, because the theobromine leaves the body so slowly.
What to do right now
- Work out what and how much. Find the wrapper. Check the type and how much is missing. Note the time.
- Run the numbers above. It takes a minute and gives your vet useful information.
- Call your vet or a pet poison line, even if the result says low risk and you’re unsure. Tell them your dog’s weight, the chocolate type, the amount and the time it happened.
- Don’t make your dog vomit at home unless a vet tells you to. If it’s needed, the vet can do it safely, usually within the first two hours.
Vets often treat chocolate cases by inducing vomiting, then giving activated charcoal and fluids. Dogs that get treatment early usually recover well.
Common questions
My dog ate one chocolate chip cookie. Should I worry?
For most medium and large dogs, one cookie is low risk because the chips are usually semisweet and the amount is small. Small dogs are another story. Enter about 0.3 oz of dark chocolate per cookie to check.
Is white chocolate safe for dogs?
It has almost no theobromine, so poisoning is very unlikely. But it’s high in fat and sugar, which can upset the stomach or trigger pancreatitis in some dogs.
What about chocolate cake, brownies or candy bars?
Estimate the chocolate in the recipe. Brownies and some cakes use cocoa powder or baking chocolate, which is far stronger. Also check the wrapper for xylitol, raisins or macadamia nuts, which are dangerous on their own.
How long after eating chocolate will my dog show symptoms?
Usually within 6 to 12 hours. Some dogs vomit sooner. Don’t wait for symptoms before you call for advice.
Can cats get chocolate poisoning too?
Yes, though cats rarely eat enough to be poisoned. If your cat has eaten chocolate, call your vet.
Sources
Last reviewed .