Chocolate Lab

Most people have probably heard that dogs shouldn't eat chocolate.  Out of those "most people" most of them at least wonder why this is the case and sometimes "common knowledge" can be a common misconception.  However in this case it is correct.

The problem occurs because of the chemical theobromine that is naturally found in cocoa beans.  It affects the central nervous system and the heart and can be poisonous to dogs in certain quantities.  Dogs metabolize it slower than humans which is why chocolate is safe for humans to consume (in less than obscene amounts).  Smaller dogs are also more susceptible because a lower amount is required to be toxic (it generally goes by body weight).

Different types of chocolates contain more or less theobromine and so are correspondingly more or less toxic to dogs.  White chocolate has the least amount of theobromine, so it is unlikely to cause too many issues for a dog.  Darker chocolates tend to have higher amounts of it, with baker's chocolate having the most, over 400 times as much as white chocolate!

Initial symptoms after a dog has eaten chocolate include vomiting, diarrhea and increased urination.  Over time there is an increase in the dog's heart rate, possibly causing hyperactivity and eventually leading to seizures, a coma or death!  Apparently cats are also at risk for this, but lacking sweetness receptors, they generally don't go after sweet food.