Sorry, but this one is not funny to me. No joke.
“Chocolate contains substances known as methylxanthines (specifically caffeine and theobromine), which dogs are far more sensitive to than people. Different types of chocolate contain varying amounts of methylxanthines. In general, though, the darker and more bitter the chocolate the greater the danger.
For instance, 8 ounces (a ½ pound) of milk chocolate may sicken a 50-pound dog, whereas a dog of the same size can be poisoned by as little as 1 ounce of Baker’s (dark) chocolate!"
Parker and Hart
Mastroianni and Hart