Chocolate toxicity in dogs: how dangerous, what to do
Chocolate poisoning in dogs follows a calculator: weight of dog, type of chocolate, grams eaten. Around 20 milligrams of theobromine per kilogram of dog is the symptom threshold. Dark and cooking chocolate are roughly 10 times more toxic per gram than milk chocolate. White chocolate is mostly fat and sugar, almost no theobromine. Below: how to do the maths quickly, when to induce vomiting at home, when to drive to the vet, and what treatment costs.
Why chocolate is toxic to dogs
Chocolate contains theobromine and caffeine, both methylxanthines. Humans metabolise theobromine in about 2 to 3 hours; dogs take 17 to 18 hours. The slow clearance is what makes it dangerous, the dose accumulates in the dog's system long after the eating happened.
The toxic dose is roughly 20 milligrams of theobromine per kilogram of body weight for early symptoms (restlessness, vomiting). 40 to 50 mg/kg causes serious cardiac and neurological signs. 100+ mg/kg is potentially fatal without treatment.
The calculator
Approximate theobromine content per 100 grams of chocolate:
| Type | Theobromine (mg/100g) | Toxic dose for 10 kg dog |
|---|---|---|
| White chocolate | 1 to 5 mg | Effectively unlimited |
| Milk chocolate | 150 to 250 mg | ~80 to 130 grams |
| Dark chocolate (60%) | 500 to 800 mg | ~25 to 40 grams |
| 70%+ dark / cooking | 800 to 1,500 mg | ~13 to 25 grams |
| Cocoa powder | 1,500 to 2,500 mg | ~8 to 13 grams |
The PetMD chocolate toxicity calculator (free online) does the maths for any combination, useful at 11pm when the kids confess they fed the dog “just one piece.”
Symptoms by dose
- Mild (20 to 40 mg/kg). Restlessness, panting, mild vomiting. Onset 4 to 12 hours.
- Moderate (40 to 60 mg/kg). Vomiting, diarrhoea, increased thirst, hyperactivity, tremors.
- Severe (60 to 100 mg/kg). Significant tremors, irregular heartbeat, hyperthermia, seizures.
- Life-threatening (100+ mg/kg). Cardiac arrhythmias, severe seizures, coma. Fatal without treatment.
Older dogs and dogs with heart conditions are higher-risk at the same dose. Pregnant dogs should always be assessed at the vet regardless of calculated dose.
When to induce vomiting
Only on vet advice, and only within 2 hours of ingestion (after that the chocolate has moved into the small intestine and inducing vomiting won't recover most of it).
The home option vets sometimes recommend is hydrogen peroxide 3% solution (the standard chemist version), 1 to 2 ml per kilogram of body weight, given orally. Don't do this without ringing the vet first. Some pets shouldn't be made to vomit, already vomiting, drowsy, very small breeds, brachycephalic breeds, dogs on certain medications.
The safer move is to drive to the vet. They can administer apomorphine (a controlled emetic) which works in 5 to 10 minutes and is more effective than peroxide.
What treatment costs
Tell people when not to wait it out: severe symptoms (tremors, seizures, irregular heartbeat) need an emergency vet within 2 hours. The emergency vet Sydney guide has after-hours clinics by suburb.
Straight answers
How much chocolate is dangerous?
Roughly 20 milligrams of theobromine per kilogram of body weight is the threshold for symptoms. A 10 kg dog hits that with about 50 grams of dark chocolate, or 250 grams of milk. Cooking chocolate is worse again, about half those amounts.
What are the symptoms of chocolate poisoning?
Restlessness and panting first, then vomiting and diarrhoea, then tremors and seizures at higher doses. Onset is 4 to 12 hours after ingestion. Severe cases progress to cardiac arrhythmias.
Should I make my dog vomit?
Only on vet advice, and only within 2 hours of ingestion. Hydrogen peroxide is the home option vets sometimes recommend. Not a default move, some pets shouldn't be made to vomit (already vomiting, drowsy, very small breeds).
How long should I monitor at home?
If you've called the vet and they've calculated the dose as below symptoms threshold, watch for 12 hours. Restlessness and panting onset means go in regardless. Any seizure or collapse, that's emergency, no waiting.
What's worse, dark or milk chocolate?
Dark, by a factor of 5 to 10. Cooking and 70 per cent dark chocolates contain the most theobromine. White chocolate has almost none, mostly fat and sugar. Cocoa powder is the most toxic form by weight.
Does the type of dog matter?
Body weight matters more than breed. Older dogs and dogs with heart conditions are higher-risk at the same dose. Pregnant dogs should always be assessed at the vet regardless of dose.
Most chocolate calls turn out to be small amounts of milk chocolate eaten by medium-sized dogs, observed at home with a phone call to the vet. The serious cases are big amounts of dark or cooking chocolate eaten by small dogs. Easter and Christmas are peak season, plan accordingly. Related: emergency vet Sydney, dog stomach issues, find a vet. Information here is general and isn't a substitute for veterinary advice.