If your dog has eaten chocolate, call your vet or an animal poison helpline straight away. Treatment works best early, often within an hour or two. This calculator gives a quick estimate of the dose so you can tell them what happened. It doesn’t replace their advice.
| Dose level | Effects | Amount of chocolate |
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Chocolate contains theobromine and a little caffeine (methylxanthines), which dogs break down far more slowly than people. The risk depends on the dose per kilogram of the dog’s body weight: dose (mg/kg) = amount eaten (g) × methylxanthine content (mg/g) ÷ dog’s weight (kg).
Typical content, from the Merck Veterinary Manual: white chocolate 0.04 mg/g, milk chocolate 2.3 mg/g, dark or semi-sweet 5.3–5.6 mg/g, baking chocolate 15.5 mg/g, dry cocoa powder 28.5 mg/g, and cocoa bean mulch about 9 mg/g. The darker and more bitter the chocolate, the more dangerous it is.
Merck lists mild signs (vomiting, diarrhoea, thirst, restlessness) from about 20 mg/kg, heart effects (racing or irregular heartbeat) at 40–50 mg/kg, and seizures at 60 mg/kg and above. Signs usually start 6–12 hours after eating and can last up to 3 days. For example, a 10 kg dog eating 50 g of milk chocolate gets 50 × 2.3 ÷ 10 = 11.5 mg/kg.
Call your vet or an animal poison helpline right away, and tell them what kind of chocolate, roughly how much, when, and your dog’s weight. Don’t try to make your dog sick at home unless a vet tells you to. If it’s within a couple of hours, a vet can often give medicine to make your dog vomit safely.
Mild signs can start at about 20 mg of theobromine per kg. That’s roughly 9 g of milk chocolate, 3.6 g of dark chocolate or 0.7 g of cocoa powder per kg of body weight. For a 10 kg dog: about 87 g of milk chocolate, 36 g of dark, or 7 g of cocoa powder.
It contains almost no theobromine, so poisoning is very unlikely, but the fat and sugar can still cause vomiting, diarrhoea or, occasionally, pancreatitis. Check whether it contained anything else, such as raisins, nuts or xylitol.
Usually within 6 to 12 hours, sometimes sooner. Theobromine stays in a dog’s body for a long time, so signs can last up to 72 hours. Don’t wait for symptoms before calling your vet.
Estimate only the chocolate or cocoa in them. A brownie made with cocoa powder or dark chocolate can be surprisingly strong. Also watch for raisins, macadamia nuts and the sweetener xylitol, which are toxic to dogs in their own right.
