I don't know if you Bs have a taste for chocolate but we have to keep ours literally on top of the refrigerator to keep Lycia from getting to it. I stumbled across this interactive chart to estimate the dangers levels from your dog eating different kinds of chocolate. Obviously first thing to do is call the vet, but I liked it for a good rule of thumb.
http://ngm.nationalgeographic.com/2007/10/pets/chocolate-chart-interactive