As your devoted pooch tries to melt your heart with those pitiful looks, just remember that if you give in you could be signing their death sentence. I know from experience it is not easy to resist those soulful eyes, to trusting and innocent. But I love my dog and want them to stay around as possible. Once a dog gets a taste of chocolate, they just cant get enough. They will gourge themselves on it and still want more.

The lethal element in chocolate that will kill a dog is called theobromine. It is a naturally occurring stimulant found in the cocoa bean and it increases urination and affects the central nervous system. It affects the heart muscle as well. The theobromine varies by different types of chocolate, some containing more than others.

Symptoms that your dog has eaten a toxic dose of chocolate include vomiting, diarrhea or hyperactivity. This usually occurs within the first few hours of ingestation. As the toxin absorbs into your dog’s bloodstream, you'll see an increase in the dog's heart rate, which can cause arrhythmia, hyperactivity, restlessness, muscle twitching, increased urination or excessive panting. This can lead to hyperthermia, muscle tremors, seizures, coma and even death.

It is difficult to tell exactly how much chocolate is fatal for a dog. As with a human, a lot depends on the health, weight and age of your dog. A 50-lb dog eating a teaspoon of chocolate or a tiny piece of brownie is not going to cause any serious problems. However, if the dog gets into a two-layer chocolate cake or that batch of brownies, it is going to cause vomiting and diarrhea in a very short period of time.

The amount of theobromine varies by the types of chocolate. White chocolate has the least amount with only 1 mg per ounce. That means it would take 250 lbs of white chocolate to cause signs of poisoning in a dog weighing 20 lbs. Baking chocolate has 450 mg of theobromine per ounce, which is far more lethal. For the most part, it is better to ignore the looks and soft whining of your companion and keep the chocolate for yourself.