Your dog ate chocolate. Is it dangerous? Enter the dog's weight, type of chocolate, and amount eaten to get an instant risk assessment based on veterinary toxicology thresholds from the Merck Veterinary Manual and ASPCA Animal Poison Control Center.
If your dog is having seizures, tremors, or collapsed — go to an emergency vet immediately. Do not use this calculator first.
ASPCA Animal Poison Control: (888) 426-4435 · Pet Poison Helpline: (855) 764-7661 (fees may apply)
If unsure, use the largest likely amount — always safer to over-estimate.
Chocolate contains methylxanthines — specifically theobromine and caffeine. In humans, theobromine has a half-life of 2–3 hours. In dogs, it's 17.5 hours. This means theobromine accumulates in a dog's system far more rapidly than it can be cleared, reaching toxic concentrations from amounts that would have no effect on a person.
| Chocolate type | Theobromine (mg/g) | Relative danger |
|---|---|---|
| White chocolate | ~0.1 | Very low |
| Milk chocolate | ~2.0 | Moderate |
| Semi-sweet chips | ~5.5 | High |
| Dark 70–85% | ~10.0 | Very high |
| Baking chocolate | ~16.0 | Extremely high |
| Cocoa powder | ~20.0 | Most dangerous |
Sources: Merck Veterinary Manual; ASPCA Animal Poison Control Center; PMC1215566
Mild signs begin
Vomiting, diarrhoea, restlessness, increased thirst
Cardiac effects
Rapid heartbeat, high blood pressure, tremors
Seizure risk
Seizures, loss of consciousness, respiratory distress
Potentially lethal (LD50)
Life-threatening without immediate treatment
Thresholds based on combined methylxanthines. Source: Merck Veterinary Manual; ASPCA APCC (Gwaltney-Brant DVM PhD); Veterinary Poisons Information Service (700+ case review).
Stay calm. Note the type of chocolate, how much is missing, and roughly when it was eaten. If your dog is already showing symptoms (trembling, vomiting, rapid breathing, seizures) — go to an emergency vet immediately without calculating anything first. If your dog seems fine, use this calculator to assess risk, then call your vet or ASPCA Poison Control (888-426-4435) if the dose is moderate or higher.
Chocolate contains two toxic compounds called methylxanthines — theobromine and caffeine. Dogs metabolise theobromine far more slowly than humans (half-life of 17.5 hours vs 2–3 hours in humans), allowing it to build up to toxic levels. Theobromine primarily affects the central nervous system, cardiovascular system, and kidneys. Signs can persist for up to 72 hours.
In order of danger: unsweetened cocoa powder and baking chocolate are most dangerous (up to 20 mg theobromine per gram). Dark chocolate (70%+) is next, followed by semi-sweet chips and standard dark chocolate. Milk chocolate is significantly less concentrated but still dangerous in quantity. White chocolate contains negligible theobromine but can cause digestive upset from fat and sugar.
It depends on the dog's weight and the type of chocolate. For milk chocolate, roughly 1 oz per pound of body weight is in the potentially lethal range. For baking chocolate, as little as 0.1 oz per pound can be lethal. A 10 lb dog eating just 1 oz of dark chocolate could show symptoms. The calculator uses veterinary toxicology thresholds to give you a precise risk level based on your specific dog and chocolate type.
Mild symptoms (20 mg/kg): vomiting, diarrhoea, increased thirst and urination, restlessness. Moderate symptoms (40–50 mg/kg): rapid or irregular heartbeat, high blood pressure, muscle tremors, excessive panting. Severe symptoms (60+ mg/kg): seizures, loss of consciousness, respiratory distress, cyanosis. Symptoms typically begin 6–12 hours after ingestion and can last up to 72 hours.
Only under direct veterinary guidance. Do not use hydrogen peroxide at home — it can cause severe haemorrhagic gastroenteritis. A vet has safer alternatives (apomorphine or ropinirole). Vomiting is typically only indicated if ingestion was within 2 hours and the dose warrants it — your vet or poison control will advise you.
Depending on severity: induce vomiting (if recent ingestion), activated charcoal to reduce further absorption, IV fluids to promote diuresis and excretion, heart monitoring for arrhythmias, anti-seizure medication if needed. Most dogs with mild to moderate toxicity recover fully with prompt treatment. The key is acting quickly — don't wait for symptoms to worsen.