With the average adult German Shepherd Dog weighing in at 80lbs they would likely need to eat several pounds of chocolate to die.
Of course, if your dog has consumed a lot of chocolate or is having a negative reaction to it, seek veterinary help immediately.
Why is chocolate poisonous to dogs?
Chocolate is poisonous to many animals. Humans can even die from it if they eat enough, although, it would be almost impossible to eat enough chocolate to die. Small dogs are usually the dogs which die from chocolate.
Chocolate is toxic to German Shepherds and all other dogs because it contains theobromine. The LD50 (lethal dose which will kill 50%) in humans is 1000 mg per kg of body weight and 300 mg/kg in dogs (according to various sources on the Internet).
A wide variety of factors determine how an animal will respond to chocolate ingestion from the dog’s age, medical condition, breed, health status and the type and amount of chocolate consumed.
National Geographic has a neat interactive chart showing how much chocolate is too much.