Estimate how serious it is, then call your vet or ASPCA Animal Poison Control at (888) 426-4435. This is not a substitute for a vet.
Dog chocolate toxicity calculator
Weight, chocolate type and amount.
Estimated dose
0
0204560+ mg/kg
Call your vet or ASPCA Animal Poison Control (888) 426-4435 now. Pet Poison Helpline: 855-764-7661.
Thresholds: mild signs from about 20 mg/kg, heart effects 40 to 50 mg/kg, seizures 60 mg/kg or more (Merck Veterinary Manual). An estimate, not a diagnosis.
The figures behind it
Methylxanthines per ounce (Merck Veterinary Manual): cocoa powder 807 mg, unsweetened baking chocolate 440 mg, semisweet or dark chocolate 150 to 160 mg, cocoa bean hulls 255 mg, milk chocolate 64 mg, white chocolate about 1 mg.
Dose levels: mild signs from about 20 mg per kg, heart effects from 40 to 50 mg per kg, seizures from 60 mg per kg. Signs usually start within 6 to 12 hours.
The result is an estimate. Chocolate brands vary, and dogs vary. Always call your vet.
Source: Merck Veterinary Manual, "Chocolate Toxicosis in Animals" (reviewed Sep 2024, updated Feb 2026).