Dogs · FAQ
Is chocolate dangerous for dogs?
Gilbert JonesResearch summary · sources below · Reviewed October 17, 2026
Why dogs react to chocolate
Chocolate contains theobromine and a little caffeine. People break these down quickly. Dogs don’t: theobromine stays in a dog’s body much longer, with a half-life of about 17.5 hours, so it builds up and affects the heart and nervous system.
How much is too much
The Merck Veterinary Manual gives these rough levels, per kilogram of the dog’s body weight:
- 20 mg/kg: vomiting, diarrhoea, drinking a lot
- 40 to 50 mg/kg: heart problems such as a racing or irregular heartbeat
- 60 mg/kg or more: seizures
How much theobromine is in chocolate (roughly, per gram):
- White chocolate: almost none (0.04 mg)
- Milk chocolate: about 2.3 mg
- Dark chocolate: about 5.5 mg
- Unsweetened baking chocolate: about 15.5 mg
- Cocoa powder: about 28.5 mg
Example: a 10 kg dog reaches the 20 mg/kg level at 200 mg of theobromine. That is about 87 g of milk chocolate (a large bar), but only about 13 g of baking chocolate.
What to do
- Work out what kind of chocolate and roughly how much was eaten, and check the wrapper.
- Call your vet or a pet poison helpline straight away, even if your dog seems fine. Signs usually start 6 to 12 hours later.
- Watch for restlessness, panting, vomiting, a fast heartbeat, shaking or seizures.
What the evidence says
Chocolate is toxic to dogs because of theobromine
Strong evidenceWell established in veterinary toxicology, with clear dose levels for mild signs, heart effects and seizures.
Dark chocolate and cocoa are far more dangerous than milk chocolate
Strong evidenceBaking chocolate has about 7 times, and cocoa powder about 12 times, the theobromine of milk chocolate.
Dogs clear theobromine more slowly than people
Strong evidenceIts half-life in dogs is about 17.5 hours, compared with about 10 hours in humans.
Related notes
Can dogs eat grapes or raisins?
No. Grapes, raisins, sultanas and currants can cause sudden kidney failure in dogs, and there is no known safe amount. If your dog eats any, call your vet or a pet poison line straight away, before signs appear.
A warm, dry nose means your dog is sick
Not true. A dog’s nose changes temperature and wetness through the day. A healthy dog can have a warm, dry nose and a sick dog can have a cold, wet one. Look at eating, drinking, energy and behaviour instead.
Dogs only see in black and white
Not true. Dogs see colour, just fewer colours than we do. They see blues and yellows well, while reds and greens look dull, greyish or brownish to them.