Chocolate is derived from the roasted seeds of Theobroma cacao. This contains caffeine and theobromine which if ingested can lead to various medical complications and may even prove fatal for dogs. Dogs have an excellent sense of smell, making it fairly easy to find any secret hiding spots for the chocolate.
Symptoms of chocolate poisoning include vomiting, diarrhea, increased body temperature, increased reflex responses, muscle rigidity, rapid breathing, increased heart rate, low blood pressure, seizures, cardiac failure, weakness, and coma.