42. Too much chocolate could lead to heart attack
Chocolate is toxic because it contains high levels of theobromine. It is a molecule like caffeine. Humans can quickly absorb and digest this ingredient, but dogs, process it rather slowly, resulting in toxic levels in their systems.
Once consumed in large amounts, theobromine causes muscle tremors, irregular heartbeat, convulsions, internal organs, worse, a heart attack. If your dog has severe hyperactivity, act quickly and contact your veterinarian, as your dog may have been poisoned.
