In sufficient amounts, the theobromine found in chocolate is toxic to non-human animals such as horses, dogs, parrots, small rodents, and cats because they are unable to metabolise the chemical effectively.[1] If they are fed chocolate, the theobromine will remain in their bloodstream for up to 20 hours, and these animals may experience epileptic seizures, heart attacks, internal bleeding, and eventually death. Medical treatment involves inducing vomiting within two hours of ingestion, or contacting a veterinarian.
A typical 20-kilogram (40-lb) dog will normally experience great intestinal distress after eating less than 240 grams (8.5 oz) of dark chocolate, but will not necessarily experience bradycardia or tachycardia unless it eats at least a half a kilogram (1.1 lb) of milk chocolate. Dark chocolate has 2 to 5 times more theobromine and thus is more dangerous to dogs. According to the Merck Veterinary Manual, approximately 1.3 grams of baker's chocolate per kilogram of a dog's body weight (0.02 oz/lb) is sufficient to cause symptoms of toxicity. For example, a typical 25-gram (0.88 oz) baker's chocolate bar would be enough to bring about symptoms in a 20-kilogram (44 lb) dog. Of course, baking chocolate is rarely consumed directly due to its unpleasant taste, but other dark chocolates' canine toxicities may be extrapolated based on this figure. As dogs like the taste of chocolate products as much as humans do, and are capable of finding and eating quantities much larger than typical human servings, they should be kept out of their reach. There are reports that mulch made from cacao bean shells is dangerous to pets (and other animals).[70][71][72] Treats made from carob can be used to substitute and pose no health threat to animals.