Chocolate is a very common toxicity in dogs. Dogs are far more sensitive to compounds found in chocolate; caffeine and theobromine cause vomiting, diarrhea, tremors, hyperthermia (a high temperature), seizures and a variety of other symptoms. Dark chocolate and baking chocolate are far more toxic than milk chocolate or white chocolate; in general, the darker the chocolate, the higher the toxicity.
Chocolate toxicity is dependent on the amount the dog ate, and the size of the dog. petmd.com has an excellent calculator that will will help you determine whether your dog ate a toxic amount or not.
If you dog ingested chocolate in the immediate past (less than a 1/2 an hour) then you need to induce vomiting ASAP. Giving hydrogen peroxide by mouth is a sure fire why to get your dog to vomit. Call your local veterinarian or emergency clinic for assistance in determining a dose for your dog and next steps, depending on the size of your dog, the amount and type of chocolate ingested. If a veterinarian is not readily available, call the pet poison hotline at 1-855-213-6680.
Your veterinarian will most likely still recommend that your dog is evaluated, monitored, and treated with additional decontamination substances, such as activated charcoal, which helps absorb any chocolate left over in the system. If you are unable to get your dog to vomit, your veterinarian will pass a stomach tube down his throat and manually remove the contents of the stomach. If you end up going to the veterinarian, be sure to bring along the wrapper from the chocolate that your dog ate: this will help your veterinarian determine next steps.
If it has been longer than a 1/2 an hour, get your dog to the veterinarian immediately, as some of the chocolate may already be absorbed into the system. Your veterinarian will still give activated charcoal, but he or she may also start your dog on intravenous fluid therapy to help flush the system.
Remember, as with any poison, the sooner your dog gets treatment, the higher likelihood he or she is to survive or not get sick, and the cheaper it will be! If your dog develops any clinical signs related to eating chocolate, then it will be much more expensive to treat your dog.
Avoid chocolate toxicity by keeping all sweets up high out of your dog’s reach.