Chocolate and Animals

Chocolate can be toxic, and sometimes even fatal, for animals. Dogs are mostly affected by chocolate poisoning due to their ability to find and “sneak” a taste of the sweet stuff, but it is important to know that cats and other small animals can be affected too.

Chocolate is made from the fruit (beans) of the cacao tree. The toxic component in chocolate is called Theobromine. Chocolate also contains caffeine which may be harmful, but it is present in much smaller doses. Theobromine affects the Central nervous system of a dog by acting as a stimulant. It is also a cardiovascular stimulant. Thoebromine also causes mild high blood pressure and even nausea and vomiting.

Some kinds of chocolate are more toxic to animals than others. While, unsweetened chocolate (also called Baker’s chocolate) contains 8 to 10 times the amount of Theobromine as milk chocolate, white chocolate contains some Theobromine, but in such a small amount that poisoning is not likely. Semi-sweet chocolate, (the kind used in chocolate chip cookies) lies somewhere between unsweetened chocolate and milk chocolate in it’s toxicity to animals.

The levels of Thebromine in chocolate are measured in units of milligrams per ounce, Baker’s chocolate having about 390- 450 mg of Theobromine per ounce of chocolate, Milk chocolate has 44-60 mg of Theobromine per ounce, and Semi-sweet chocolate contains about 195- 225 mg per ounce.  Although it is reported that the toxic dose of Theobromine (and caffeine) for pets is 100-200 mg/kg, various other studies have shown that number to be much lower, and in some cases as low as 20 mg/kg.

For example, say you have a 100 pound dog. Using the 20mg/kg equation, a dog of that weight would require about 18 ounces (+/-) of milk chocolate to have problems associated with Theobromine poisoning. This equation does not mean all animals fitting this description WILL get sick. Each animal is different and some may have no/little effect at all. This standard equation is more conservative than the 200mg/kg equation, but it is better safe than sorry.

Signs of toxicity are usually seen within 12 (or less) hours. Some of the neurological signs include excitement, nervousness, trembling or muscles spasms and seizures. Gastrointestinal signs are Vomiting and diarrhea. At higher levels of toxicity, excessive thirst or urination may occur. Other more serious but rare signs are coma and even death, mostly due to heart rhythm irregularity.

The treatment of Theobromine and caffeine poisoning is dose dependent, meaning that the size and weight of the animal, along with the type and amount of chocolate are used to determine the correct treatment. There is no specific antidote for Theobromine poisoning in animals, but IV fluids, emetics, activated charcoal, anti-seizure medications, and cardiac medications may be administered. The IV fluids are used to prevent dehydration from vomiting, diarrhea, and /or increased urination, and to "flush" the Theobromine out of the system. Emetics are medications that induce vomiting. It is usually used when the ingestion of chocolate is within 4 hours and sometimes up to 6-8 hours post chocolate ingestion may still be effective. Activated charcoal is used for ingestion greater than 4 hours prior to treatment, or for patients that show continued signs of toxicity. Anti-seizure medications are used in patients having seizures and/or muscle tremors. Cardiac medications are often used in patients exhibiting irregular heart rates or rhythms.

If you think (or see evidence) that your pet has ingested chocolate, contact your veterinarian immediately, with as much information you have, including the type of chocolate, amount consumed, and if possible the time of consumption.

The author of this article assumes no liability for misdiagnosis. This article is for information purposes only and is not intended as a substitute for professional veterinary attention. In case of emergency, contact the Animal Poison Control Center  888-4ANI-HELP (888-426-4435)