Dog Chocolate Toxicity Calculator
Did your dog eat chocolate? Enter the dog’s weight, the type of chocolate and how much was eaten to get the theobromine dose in mg/kg and the toxicity level from the Merck Veterinary Manual.
How it works
methylxanthines (mg) = chocolate eaten (g) × theobromine + caffeine content (mg/g) · dose = methylxanthines ÷ dog’s weight (kg) · ≥ 20 mg/kg mild signs · ≥ 40 heart effects · ≥ 60 seizures
Chocolate is toxic to dogs because of theobromine and caffeine (methylxanthines), which dogs clear very slowly. The Merck Veterinary Manual lists the content of each chocolate — about 2.3 mg/g in milk chocolate, 5.5 mg/g in semisweet and dark, 15.5 mg/g in unsweetened baking chocolate and 28.5 mg/g in cocoa powder — and the dose bands: mild vomiting, diarrhea and thirst from 20 mg/kg, heart effects at 40–50 mg/kg and seizures at 60 mg/kg or more. Signs start 6–12 hours after eating and can last up to three days, so call your vet early: inducing vomiting within the first hours works best.
Worked example
A 10 kg dog eats 50 g of semisweet chocolate: 50 × 5.5 = 275 mg of theobromine and caffeine, and 275 ÷ 10 = 27.5 mg/kg — above the 20 mg/kg line, so mild signs are likely and you should call your vet now. About 109 g of the same chocolate would reach the 60 mg/kg seizure level.
Sources: Merck Veterinary Manual — Chocolate Toxicosis in Animals · ASPCA Animal Poison Control — Chocolate
Frequently asked questions
How much chocolate is toxic to a dog?
Mild signs can start at 20 mg/kg of theobromine plus caffeine. For milk chocolate that is about 9 g per kg of body weight (0.14 oz per lb); for dark or semisweet chocolate about 3.6 g per kg; and for baking chocolate or cocoa powder less than 1.5 g per kg. Darker chocolate is far more dangerous.
What are the symptoms of chocolate poisoning in dogs?
Vomiting, diarrhea, thirst, restlessness, panting, a fast heart rate and, at high doses, tremors, seizures and collapse. Signs usually appear 6–12 hours after eating and can last 72 hours because dogs eliminate theobromine slowly.
Is white chocolate dangerous for dogs?
White chocolate contains almost no theobromine, so poisoning is very unlikely, but the fat and sugar can still cause vomiting, diarrhea or pancreatitis. Wrappers and xylitol-sweetened products are separate dangers.
What about very dark chocolate (70–90% cacao)?
High-cacao bars can contain more theobromine than the "sweet dark" average used here. To stay on the safe side, calculate an 85% bar as unsweetened baking chocolate and let your vet know the exact percentage.
Should I make my dog vomit at home?
Not without professional advice. A vet or pet poison helpline will tell you whether to induce vomiting based on the dose and timing; some home methods (salt, hydrogen peroxide in the wrong dose) cause their own harm.
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This estimate does not replace a veterinarian. If your dog ate chocolate, contact your vet or a pet poison helpline right away, whatever the result.