Your dog ate chocolate. Don't panic, don't guess — calculate.
Based on theobromine toxicology: mild signs from ~20 mg/kg, serious from ~40 mg/kg, potentially lethal from ~60–100 mg/kg. Every dog is different — smaller, older, or sick dogs are at higher risk. This calculator is not veterinary advice. If your dog ate chocolate, calling your vet is always the right move.
Chocolate contains theobromine, a stimulant humans process easily but dogs break down very slowly. It builds up in their system, overstimulating the heart and nervous system. Dark chocolate and cocoa powder pack far more theobromine per ounce than milk chocolate — that's why a little baker's chocolate can be worse than a whole milk chocolate bar.
Don't let this happen again — get the printable list of the 30 most dangerous foods for dogs.