I did not know that yesterday!

Chocolate contains theobromine, an alkaloid that dogs can't metabolize quickly. If a dog ingests a large amount of chocolate, the theobromine can build up and reach a toxic level of concentration, leading to cardiac arrest. Different types of chocolate are more harmful than others, and the effects will vary, depending
upon the size and weight of the dog. However, it is potentially lethal.

If you know your dog has ingested chocolate (signs of chocolate poisoning include vomiting, diarrhea, excessive urination, a quick heart rate, and rapid breathing) take him to a vet immediately.

a quick review of some of the other household items that can cause harm to your fuzzy friend. For instance, did you know common plants such as azaleas, rhododendron, and foxglove can all cause heart failure if ingested?

Some other articles dog owners should check out include "Common Household Items Hazardous to Your Dog " from Pet Warehouse, and "Chocolate Poisoning in Dogs," by veterinarian Kevin Fitzgerald.

But why isn't theobromine poisonous to humans? To answer that question, I tried a Yahoo! search on "theobromine," which led me to an article from About.com. There, I learned that humans can break down and excrete theobromine much more efficiently than dogs, rendering it effectively harmless.

Just remember: Chocolate's a tasty treat for humans, but it can be fatal to our four-legged friends.