Can dogs eat dark chocolate?

Toxic
Dark chocolate is highly toxic to dogs because it contains more methylxanthines than milk chocolate.

Quick notes

Sources

All pets (comparison)

Pet Safety Notes
Dog Toxic Dark chocolate is highly toxic to dogs because it contains more methylxanthines than milk chocolate.
Cat Toxic Highly toxic to cats and may cause severe signs even with smaller amounts.
Rabbit Toxic Highly unsafe for rabbits and should never be fed.
Parrot Toxic Highly unsafe for parrots; dark chocolate has concentrated toxic compounds.