Short answer: Severe toxicity starts at about 20 mg of theobromine per pound of body weight, and potentially fatal doses begin around 50 mg/lb. For a 30-lb dog that’s roughly 1 oz of baking chocolate, 3 oz of dark chocolate, or 30 oz of milk chocolate.
What you should actually do
- Theobromine content varies wildly: white chocolate ~0.1 mg/g, milk chocolate ~2 mg/g, dark chocolate ~15 mg/g, baking chocolate ~16 mg/g, cocoa powder ~25 mg/g.
- Toxic threshold (mild signs – vomiting, restlessness): ~9 mg/lb. Severe (tachycardia, tremors, seizures): ~20 mg/lb. Potentially fatal: 50 mg/lb (Plumb’s).
- Onset is usually 6-12 hours; signs can persist 72 hours because theobromine has a half-life of about 17.5 hours in dogs.
- Inducing vomiting is most effective within 2 hours of ingestion and only under vet guidance – activated charcoal is given for several doses to interrupt enterohepatic recycling.
- Bag the wrapper – the % cacao or oz weight on the label is what your vet or poison control needs to calculate risk.
Theobromine is a methylxanthine that dogs metabolize very slowly – their half-life is about 5x longer than ours – which is why a dose that’s harmless in a human is dangerous in a dog. The toxic effects are stimulant: heart racing, hyperactivity, then tremors and seizures as serum levels rise.
Call ASPCA Animal Poison Control (888-426-4435; $95 consult fee but worth it) or Pet Poison Helpline (855-764-7661) before you drive to the vet – they will give you a case number, calculate the dose, and tell the ER vet exactly what they recommend. Treatment is usually supportive: induced vomiting, multi-dose activated charcoal, IV fluids, and anti-seizure medication if needed. Most dogs recover fully with prompt treatment.
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⚕️ Medical Disclaimer
The information on this page is intended for educational purposes only and does not replace a hands-on veterinary examination. Drug doses depend on your dog’s complete clinical picture, concurrent medications, and the exact product formulation. Always confirm dosing with your veterinarian before administering any medication, and contact a 24-hour veterinary emergency service or animal poison control immediately if you suspect a medication overdose or adverse reaction. Editorial standards: every drug dose published on PuppaDogs is cross-checked against multiple authoritative veterinary references and reviewed by PuppaDogs Veterinary Editorial Team before publication.
