Chocolate contains theobromine, a naturally occurring stimulant found in the cocoa bean; theobromine increases urination and affects the central nervous system as well as heart muscle. While amounts vary by type of chocolate, it’s the theobromine that is poisonous to dogs. The danger from chocolate consumption vary on the size and health of your dog, quantity of theobromine eaten, and sensitivity to poison substances which is different for each type of dog.

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