Trick-or-Treat? Keep Fido away from those yummy Halloween treats! Candy, especially chocolate, can be toxic to pets. Chocolate poisoning can be lethal to pets and symptoms can include vomiting, diarrhea, excessive urination, muscle tremors, abnormal drooling, hyperactivity, seizures or coma. If you notice these symptoms of chocolate poisoning in your pet, go to your veterinarian or an animal emergency hospital right away, because your pet’s life may be in danger.