Each year vets report more cases of dogs poisoned by chocolate. Chocolate contains caffeine and theobromine which can be very toxic to dogs. The highest concentration of caffeine is found in dark chocolate. Milk chocolate is less dangerous as it contains less amount of caffeine. Chocolate could be very harmful even if you administer moderate amounts to your dog. One of the symptoms of chocolate dog poisoning is fever. Other symptoms might include low blood pressure, increased heart rate, diarrhea, vomiting, etc. Try keeping chocolate products out of your dog’s reach.