Chocolate and cocoa contain both of the methylxanthines, theobromine and caffeine, which can be toxic to animals if fed to excess. The most dangerous is baking chocolate which contains seven to ten times the amount of theobromine that ordinary milk chocolate does. One ounce of baking chocolate can be life-threatening to a 10 lb dog. The ingestion of approximately 24 oz of milk chocolate would result in a potentially lethal dose for a 27 lb