Chocolate contains a xanthine compound, theobromine, that is toxic in sufficient quantities. Examples of other xanthine compounds are caffeine and theophylline. The toxicity from all of these compounds is similar.
The Toxic Amount of Chocolate for Dogs
It takes a fairly large amount of chocolate to cause problems. In "The Handbook of Small Animal Practice" by Dr. Rhea Morgan, the following data is given:
The toxic dose of theobromine is about 100 to 150mg/k.
Milk chocolate contains 6mg of theobromine per ounce. Semi-sweet chocolate contains about 22mg/oz. and baking chocolate about 35 to 45mg/oz.
From this it is pretty easy to see that milk chocolate poses only a minor threat while the other forms of chocolate can be a bigger problem.
Symptoms of Chocolate Toxicity
Xanthines affect primarily the central nervous system, the cardiovascular system and peripheral nerves. There is a diuretic effect as well. So the sign seen with toxicity include hyperexitablility, hyper irritability, increased heart rate, restlessness, increased urination, vomiting and muscular tremors or tenseness. Under some circumstances these signs can lead to secondary problems like hyperthermia. In severe cases, seizures or cardiac arrest can occur. Death can result from severe intoxication.
Chocolate Toxicity treatment for Dogs
There is no specific antidote for this poisoning. Inducing vomiting can help if the ingestion is known and has occurred within one to two hours. Administration of activated charcoal may inhibit absorption of the toxin from the digestive tract. It may be necessary to use medications to control the effects of the poisoning, especially seizure control medications, oxygen therapy, intravenous fluids, and medications to control the effects on the heart.
With ingestion of milk chocolate, diarrhea is a common secondary problem. This may require therapy and often occurs 12 to 24 hours after eating the chocolate.
If you suspect chocolate poisoning and your dog or cat is showing clinical signs of the problem, it is important to contact your vet.