Give chocolate to loved ones and you could end up poisoning them. That is, if the loved ones are your pets. Even small amounts of theobromine, an ingredient in chocolate, can cause vomiting and restlessness in pets and can even lead to death. The lethal dose of theobromine depends on the size of the dog and the type of chocolate. Ounce for ounce, baking chocolate has six to nine times as much of the substance as milk chocolate does.