It depends on three things: the type of chocolate, how much your dog ate, and how much your dog weighs. Dark and baking chocolate are far more dangerous than milk chocolate.
Chocolate contains theobromine and caffeine (methylxanthines). Vets measure the risk in milligrams per kilogram of body weight:
This table shows roughly how much chocolate reaches the 20 mg/kg level, where mild signs start. Double it for the level that affects the heart.
| Chocolate | 5 kg / 11 lb dog | 10 kg / 22 lb dog | 25 kg / 55 lb dog |
|---|---|---|---|
| Cocoa powder ~800 mg per oz | 4 g 0.12 oz | 7 g 0.25 oz | 18 g 0.6 oz |
| Baking chocolate (unsweetened) ~450 mg per oz | 6 g 0.22 oz | 13 g 0.4 oz | 31 g 1.1 oz |
| Dark / semisweet ~160 mg per oz | 18 g 0.6 oz | 35 g 1.2 oz | 89 g 3.1 oz |
| Milk chocolate ~64 mg per oz | 44 g 1.6 oz | 89 g 3.1 oz | 221 g 7.8 oz |
White chocolate has almost no theobromine, but its fat and sugar can still upset the stomach. Brands vary, so these are estimates.
Signs usually appear within 6 to 12 hours.
Don't make your dog vomit unless a vet tells you to.
US & Canada, a fee may apply. Outside North America, call your nearest emergency vet.