Unfortunately, dogs seem to love chocolate as much as people do, despite being very sensitive to its adverse effects. Chocolate contains theobromine and caffeine, which can, in large amounts, disrupt a dog's nervous and cardiovascular system. The darker the chocolate the greater the concentration of these potent stimulants; baking chocolate is by far the most toxic form. The high sugar and fat content of most chocolates can also disrupt the digestive system and lead to a potentially serious case of pancreatitis.
When a dog ingests relatively small amounts of chocolate, hyperexcitability, vomiting and diarrhea typically result. More severe cases can develop increased thirst and urination, difficulty walking, tremors, seizures, an increased heart rate, an irregular heart rhythm and may even die. Diagnosing chocolate poisoning is usually based on a history of access to the substance, but blood work and heart and blood pressure monitoring may all be necessary to keep track of the dog's condition.
If a dog is found soon after it has gotten into chocolate, inducing vomiting, lavaging its stomach, and/or administering activated charcoal can all significantly reduce the amount of theobromine and caffeine absorbed into the animal's system. Fluid therapy and medications to treat seizures and heart arrhythmias may also be necessary. With prompt and appropriate care, most dogs that ingest even large amounts of chocolate recover without incident.
Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008