Most humans love indulging in their favorite chocolate treat but unfortunately, ingesting chocolate can result in significant illness for your dog. Chocolate is toxic for your dog because it contains both caffeine and a chemical called theobromine which are both from the methylxanthine family; two chemicals that dogs cannot metabolize as well as humans.
If your dog ate chocolate, contact your emergency vet immediately.
Use this calculator from PetMD to learn how it will affect your dog.