Being in the animal community, I have heard many stories.... I believe chocolate is bad for dogs in general. That is my opinion...
I have, however, heard many more stories of dogs dying because of chocolate than not.
I will share that I had a few people, a few "old timers" that didn't know any better, and gave their dogs some mm's every day...and the dogs lived to be 12 to 16 years of age. I think that is not the norm. Granted, it was not dark chocolate, or maybe they developed a tolerance, or maybe it did take a few years off of their life. I don't know.
I won't take the chance. I have found that chocolate, onions, raisions, grapes,tomato leaves, green skin on potatoes, certain nuts and so on "can" be toxic.
Regardless, I am not going to chance it.