Chocolate Toxicity In Dogs

by Henry M. Jones, Jr, DVM

The active ingredient in chocolate is theobromine, a xanthine compound. The concentration of theobromine varies with the type of chocolate. Milk chocolate has approximately 44mg theobromine/oz. Semisweet chocolate has 150mg/oz. Baking chocolate has 390mg/oz. According toKirk and Bistner's Handbook of Veterinary Procedures and Emergency Treatment- 6th Edition, the half-life of theobromine in the dog is 17.5 hours, and the LD50 in the dog is 50-75mg theobromine per lb. of body weight. Therefore, for a 10 lb. dog, the toxic dose of baking chocolate would be only one oz, but the dog would have to eat almost 3oz of semisweet or 10oz of milk chocolate to get the same dose of theobromine. Lower doses have also been reported to cause clinical signs including vomiting, excitement, increased urination, muscle tremors, and rapid heart rate. In severe cases, seizures or cardiac arrest can occur. The fat in chocolate can also be harmful, often leading to diarrhea and enteritis.

There is no specific antidote for chocolate toxicity. Induction of vomiting may be helpful if done soon after ingestion. Hydrogen Peroxide is a good emetic for this purpose. In a beagle size dog, give 2 to 3 tablespoons of Hydrogen Peroxide orally and wait five minutes. If the dog hasn't vomited by then, double the amount. Administration of activated charcoal slurry or gastric lavage may inhibit absorption of theobromine from the GI tract. In more severe cases, it may be necessary to control CNS excitation, support respiration and cardiovascular function, control arrhythmias, and control electrolytes and acid-base balance.