Chocolate contains theobromine – a substance toxic to dogs. Baking chocolate contains more theobromine per ounce than semisweet chocolate, which, in turn, contains more theobromine than milk chocolate. While most lethal cases of chocolate poisoning occur when small dogs eat large quantities of baking chocolate, owners should nonetheless keep their dogs and chocolates well-separated.
If you witness your dog eating chocolate or if it shows any signs of chocolate toxicity (anxiety, pacing, hyperexcitability, excessive thirst and urination, vomiting, or seizures): call your vet immediately and tell him or her what type of chocolate your dog ate, how much you think it ate, how long ago it indulged itself, and how much your dog weighs.
If you find your dog within a couple of hours of ingesting the chocolate, your vet will either instruct you on how to induce vomiting or ask you to bring your dog to the clinic to have its stomach pumped.
If more than a couple of hours have passed, the toxin will already be circulating in your dog’s system, so your vet will provide supportive therapy (such as intravenous fluids and drugs to control hyperexcitability) while your dog’s body works to detoxify itself.
For more information call Animal Poison Control (they will charge an initial fee for a consult) 1-800-548-2423