Theobromine: The Offending Substance



A substance called theobromine is what makes chocolate a dangerous food to dogs. Theobromine is a xanthine compound that belongs to the same family that caffeine and theophylline do.

If your dog accidentally ingests chocolate, his reaction will depend on the size of your dog, your dog's sensitivity, and how much theobromine is present in the chocolate. Typically, your dog will become quite ill if it ingests too much chocolate.

Concentration of Theobromine in Chocolate Allowable

- 1 oz. milk chocolate for every 1 lb of a dog's weight

- 1 oz. semi-sweet chocolate for every 3 lbs of a dog's weight

- 1 oz. Baker's chocolate for every 9 lbs of a dog's weight

Based on these figures, a 2 oz. serving of Baker's chocolate poses a risk of adverse reaction to a 15-lb. dog, while 2 oz. of milk chocolate may only result in mild digestive symptoms in the same animal.

Signs of Chocolate Poisoning

Xanthine compounds like theobromine target the peripheral nerves, central nervous system, and cardiovascular system. Theobromine, like caffeine, is a diuretic so if your dog ingests excessive amounts of chocolate high in theobromine concentration, your dog will be vomiting, having diarrhea, and urinating frequently in large amounts. Your dog will also be too excitable and irritable. His heart rate will be high and he will experience muscle tremors.

Treatment for Chocolate Poisoning

There is no known antidote to theobromine or xanthine poisoning in dogs. However, there are a number of ways to arrest or lessen their adverse effects both immediately and for the longer haul. Activated charcoal may be administered to inhibit the absorption of the offending substance, and anticonvulsants may be given to control neurological symptoms. Oxygen therapy, intravenous medications, drinking water and other fluids may be prescribed by the veterinarian to protect the dog's heart.

If your dog ingests milk chocolate, he may have diarrhea, which can last from 12 to 24 hours. Make sure that your dog is given lots of water and other liquids so that he doesn't become dehydrated. If your dog ingests chocolate and displays any of the symptoms of chocolate poisoning, call the veterinarian right away. He will be able to prescribe the best treatment for your dog.