Because chocolate contains caffeinelike chemicals, dogs who eat it can become very sick. While dogs rarely die from ingesting chocolate, they can become seriously ill. Contact your veterinarian if your dog eats any chocolate, and try to determine the type and amount of chocolate consumed.
Chocolate’s Toxic Properties
Chocolate's toxicity precipitates from the presence of a chemical called theobromine. Doctors use it as a diuretic, heart stimulant, smooth muscle relaxant and blood vessel dilator, but theobromine can cause serious health problems for dogs. According to the VCA Animal Hospitals website, as little as 20 milligrams per kilogram of your dog's body weight can cause minor symptoms such as hyperactivity, intestinal disturbance and agitation. Cardiac symptoms occur at dosages of 40 milligrams per kilogram, while twitching, seizures and other neurological symptoms begin to manifest at doses of 60 milligrams per kilogram. The Veterinary Information Network says theobromine's LD50 -- the amount necessary to kill half of the animals in a research study – is 100 milligrams per kilogram, but you should consider any amount over 40 milligrams per kilogram an emergency.
Different Types of Chocolate
Not all chocolates are created equally: The amount of theobromine varies from one recipe to the next. Dark and bitter chocolate such as baking chocolates have the highest theobromine concentrations -- sometimes as high as 450 milligrams of theobromine per ounce of chocolate -- making them the most dangerous. Milk chocolates are slightly less dangerous, as most contain around 50 milligrams of theobromine per ounce. While still an inappropriate food for your dog, white chocolate has very little theobromine -- most varieties have about 0.25 milligram of theobromine per ounce.
What to Expect From the Vet
Contact your veterinarian immediately after discovering that your dog has eaten chocolate. Be prepared to tell the vet the approximate weight of your dog and the amount of chocolate he consumed. Share any symptoms your dog is experiencing, and follow all of the vet's recommendations. Your vet may instruct you to bring the dog in for immediate treatment or, if the amount ingested was relatively little, he may encourage you to monitor the situation at home. If you bring your dog in for treatment, the veterinarian may administer medications to make your dog vomit and activated charcoal to absorb some of the theobromine. Additionally, your vet may provide your dog with beta-blockers to slow his heart rate and intravenous fluids to keep him hydrated.
If your dog has eaten chocolate within the past two hours, your veterinarian may instruct you to induce vomiting. To do so, measure out 1 milliliter of 3 percent hydrogen peroxide per pound of your dog's body weight -- a teaspoon has a capacity of approximately 5 milliliters. Use a turkey baster to suck up the peroxide, then squirt it into the back of your dog's throat. Never administer more than 45 milliliters of peroxide, regardless of your dog's size. If vomiting does not occur within about 15 minutes, repeat the procedure. Sometimes it is helpful to feed your dog a small meal before inducing vomiting, but it is not imperative; if your dog shows no interest in food, simply administer the hydrogen peroxide.
Regardless of the amount of chocolate ingested or the size of your dog, several symptoms warrant immediate veterinary attention. Take your dog to the emergency veterinary hospital if he displays cardiac symptoms, such as rapid pulse, or rapid breathing. Seizures, muscle contractions or extreme agitation should prompt you to take your dog in for immediate treatment.