Found this article and thought I would share it. Keep your pets safe! 
Halloween is HERE. That means that many of our patients will have increased access to CHOCOLATE. Now, I'll admit that chocolate is one of my all time favorite food groups. But, I'm a human.
In sufficient quantities, Chocolate can be toxic to dogs and cats.
The problem with chocolate is that is contains theobromine and caffeine. Both of these chemicals can cause poisonings in dogs and cats. Chocolate overdose is typically a bigger problem for dogs than it is for cats.
According reports of the experiences at the ASPCA Animal Poison Control Center, pets can develop mild symptoms after ingesting as little as 20 mg/kg of theobromine and caffeine. There are also differences in the amount of theobromine and caffeine contained in various types of chocolate. Dark chocolate and Bakers chocolate are the worst and Milk chocolate is the least harmful. The net effect is that a dose of less than one (1) ounce of milk chocolate per pound of dog (2 oz/kg) is potentially lethal to dogs.
Symptoms of chocolate toxicity include the following:
restlessness
hyperexcitability
excessive panting
palpitations
increased heart rate
vomiting
diarrhea
convulsions
With mild milk-chocolate overdose in medium and large breed dogs, diarrhea and dehydration beginning about 12-24 hours after the chocolate ingestion may be the only symptom. Smaller dogs are often more seriously affected.
Since there is no specific antidote for chocolate overdose, we treat affected pets symptomatically. It takes about 52.5 hours for a dose of chocolate to be cleared from a dog's body. So that means we are looking at 1-3 days of treatment. Treatment typically includes induction of vomiting, fluid therapy, stomach/intestinal protectants, and sedatives if needed.