Chocolate is toxic to dogs. Dogs love chocolate. The two don’t mix.
It’s the theobromine and caffeine in chocolate that is toxic to dogs, the amount present depends on the type of chocolate- it’s highest in dark or cooking chocolate, less in milk and white has negligible amounts. As little as 20g of cooking chocolate can cause upset for a 10kg dog.
Side effects of chocolate consumption range from a temporarily upset stomach to severe abdominal pain, vomiting and pancreatitis. Larger amounts can cause hyperactivity, tremors, seizures, abnormal heart rhythms and even death.
If your dog has eaten chocolate you should call a vet clinic as soon as possible and if appropriate they will be made to vomit and treated as necessary.
The sooner treatment and supportive care can be started the better the outcome for your best friend.