Worried your dog ate chocolate? Enter its weight, the type of chocolate and how much, and this tool estimates the theobromine dose and how serious it may be.
If your dog has eaten chocolate, contact your vet or a pet poison line now. This tool is a general guide only, not veterinary advice, and cannot replace an examination. Signs can take hours to appear — don't wait for symptoms.
Quick answer: Chocolate is toxic to dogs because of theobromine. Risk rises with the dose per kg: under 20 mg/kg is usually mild, 40–60 mg/kg can affect the heart, and above 60 mg/kg risks seizures. Darker chocolate is far more dangerous than milk.
Guide bands: <20 mg/kg minimal; 20–40 mild (vomiting, diarrhoea, restlessness); 40–60 moderate (racing heart, tremors); >60 severe (seizures). Any dose can affect a small or unwell dog — always check with a vet.
Chocolate contains theobromine (and caffeine), stimulants that dogs clear from their bodies very slowly, so they build up to harmful levels. How dangerous a given amount is depends on the dog's weight and the type of chocolate — darker and more bitter chocolate has far more theobromine than milk chocolate.
How the toxicity dose is worked out
Theobromine (mg) = amount × theobromine per unit Dose (mg/kg) = theobromine (mg) ÷ dog weight (kg)
A 20 lb (9.1 kg) dog eats 2 oz of milk chocolate: theobromine ≈ 2 × 64 = 128 mg, so the dose is 128 ÷ 9.1 ≈ 14 mg/kg — minimal risk. The same dog eating 2 oz of dark chocolate gets about 33 mg/kg — enough for stomach upset — and just 1 oz of baking chocolate would push a 10 lb dog past 80 mg/kg, a serious dose.
Signs of chocolate poisoning in dogs
Symptoms usually start within 6–12 hours and can include vomiting, diarrhoea, restlessness, excessive thirst, a racing heart, muscle tremors and, at high doses, seizures. Because theobromine lingers, effects can last a day or more. If you know or suspect your dog has eaten chocolate, call your vet or a pet poison helpline straight away rather than waiting for symptoms.
Frequently asked questions
How much chocolate is toxic to a dog?
It depends on the dog's weight and the chocolate type. Roughly, problems begin around 20 mg/kg of theobromine and serious effects above 60 mg/kg. Dark and baking chocolate reach these levels in very small amounts.
Is white chocolate dangerous?
It has very little theobromine, so toxicity is unlikely, but the fat and sugar can still upset a dog's stomach or trigger pancreatitis.
How long after eating chocolate will a dog show symptoms?
Usually 6–12 hours, and effects can last more than a day. Don't wait — contact a vet as soon as you know.
What should I do right now?
Note the type and amount of chocolate and your dog's weight, then call your vet or a pet poison line immediately for advice tailored to your dog.
For general information only — not veterinary advice, diagnosis or treatment. Theobromine content varies between products. Always contact a vet or pet poison service about a specific incident.
Written by the CalcPine team · Reviewed for accuracy · Last updated 24 July 2026 · Method: dose (mg/kg) = theobromine ÷ body weight; risk bands 20 / 40 / 60 mg/kg.
