Dog chocolate toxicity calculator
Chocolate is dangerous to dogs because of theobromine and caffeine. Mild signs can start at about 20 mg of these per kg of body weight, heart effects at about 40 mg/kg, and seizures at about 60 mg/kg. Dark and baking chocolate hold far more than milk chocolate. If your dog ate any, call your vet now.
Reviewed by a vet. Sources checked 30 September 2026. How we check facts
How chocolate toxicity works in dogs
The toxic components in chocolate are theobromine and caffeine. Both are methylxanthines, and dogs metabolise them far more slowly than people do. They build up in the body, so signs can appear hours after the chocolate was eaten and last a long time.
Dog chocolate toxicity chart: how much is toxic?
The table gives the amount of each chocolate that brings a dog to about 20 mg of theobromine and caffeine per kg, the dose where signs of poisoning can start. Heart effects can start at about 40 mg per kg, so double each amount. Amounts are rounded down. Brands vary, so use the calculator for the exact chocolate your dog ate, and call your vet even for a smaller amount.
| Dog's weight | Milk chocolate | Dark or semi-sweet chocolate | Baking (unsweetened) chocolate | Dry cocoa powder |
|---|---|---|---|---|
| 2 kg (4 lb) | 17 g (0.5 oz) | 7.1 g (0.2 oz) | 2.5 g (under 0.1 oz) | 1.4 g (under 0.1 oz) |
| 5 kg (11 lb) | 43 g (1.5 oz) | 17 g (0.5 oz) | 6.4 g (0.2 oz) | 3.5 g (0.1 oz) |
| 10 kg (22 lb) | 86 g (3 oz) | 35 g (1.2 oz) | 12 g (0.4 oz) | 7 g (0.2 oz) |
| 20 kg (44 lb) | 173 g (6.1 oz) | 71 g (2.5 oz) | 25 g (0.8 oz) | 14 g (0.4 oz) |
| 30 kg (66 lb) | 260 g (9.1 oz) | 107 g (3.7 oz) | 38 g (1.3 oz) | 21 g (0.7 oz) |
| 40 kg (88 lb) | 347 g (12.2 oz) | 142 g (5 oz) | 51 g (1.7 oz) | 28 g (0.9 oz) |
Example: a 10 kg (22 lb) dog that ate a 45 g milk chocolate bar got about 10 mg per kg, below the level where signs usually start. The same dog and 45 g of dark chocolate is about 25 mg per kg, which can cause signs. Call your vet.
Theobromine and caffeine by chocolate type
The darker and more bitter the chocolate, the more methylxanthines it holds per gram:
- Dry cocoa powder: 28.5 mg per g, about 808 mg per oz.
- Baking (unsweetened) chocolate: 15.5 mg per g, about 439 mg per oz.
- Dark or semi-sweet chocolate: 5.6 mg per g, about 159 mg per oz.
- Milk chocolate: 2.3 mg per g, about 65 mg per oz.
- White chocolate: 0.04 mg per g, about 1 mg per oz.
Total methylxanthines per gram, because the Merck dose thresholds are stated for total methylxanthines. Dark chocolate uses the top of the Merck range (5.3 to 5.6 mg/g) so the estimate errs high. Brands vary.
Fat and sugar in any chocolate can also upset a dog's stomach, and a fatty treat can trigger pancreatitis.
Chocolate and dogs: common questions
Why is chocolate toxic to dogs?
Chocolate contains theobromine and caffeine. Dogs clear these compounds very slowly, so they build up and overstimulate the heart and nervous system.
How much chocolate is dangerous for a dog?
It depends on the chocolate and the dog. Mild signs can start at about 20 mg of theobromine and caffeine per kg of body weight, heart effects at about 40 mg/kg and seizures at about 60 mg/kg. For a 10 kg dog, about 36 g of dark chocolate reaches 20 mg/kg. Small dogs reach these doses with very little.
How long after eating chocolate will my dog show signs?
Signs usually start within 6 to 12 hours and can last up to 3 days in severe cases. Do not wait for signs. Call your vet as soon as you know your dog ate chocolate.
What are the signs of chocolate poisoning in dogs?
Early signs include vomiting, diarrhoea, thirst, restlessness and panting. Serious signs include a fast or irregular heartbeat, tremors, seizures and collapse.
Should I make my dog vomit at home?
No. A vet may make your dog vomit within about 2 hours of eating chocolate, but do not do this at home. Home methods such as salt or hydrogen peroxide can cause serious harm.
Sources
- Chocolate Toxicosis in Animals. Merck Veterinary Manual. Accessed 30 September 2026.
- Chocolate. ASPCA Animal Poison Control Center. Accessed 30 September 2026.
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