Chocolate Toxicity in Dogs

Chocolate Toxicity in Dogs


How many times have you been eating that chocolate chip cookie when you look over and see those sad puppy dog eyes staring at you?   You remember hearing that chocolate is toxic to dogs.   But what makes chocolate toxic to dogs and why is it that some dogs ingest it and don’t get sick?   Here are some facts to clear up some of the confusion surrounding chocolate toxicity in dogs.


Toxic doses of theobromine are reported to be as low as 20 mg/kg, where agitation, hyperactivity and gastrointestinal signs (such as drooling, vomiting, and diarrhea – all which may smell like chocolate) can be seen.  At doses > 40 mg/kg, cardiac signs can be seen, and include a racing heart rate, high blood pressure, or even heart arrhythmias.  At doses > 60 mg/kg, neurologic signs can be seen, and include tremors, twitching, and even seizures.  Fatalities have been seen at around 200 mg/kg (approximately 100 mg/lb), or when complications occur.


The amount of toxic theobromine varies with the type of chocolate.  The darker and the more bitter the chocolate, the more dangerous it is to your pets. Cooking or baking chocolate and high quality dark chocolate contains between 130-450 mg of theobromine per ounce of the product, while common milk chocolate only contains about 44-58 mg/ounce. White chocolate barely poses any threat of chocolate poisoning, with only 0.25 mg of theobromine per ounce of chocolate (that said, dogs can still get sick from all that fat and sugar, resulting in pancreatitis!).  This means that for a medium size dog, weighing 50 pounds it would take only 1 ounce of baker’s chocolate or 8 ounces of milk chocolate to potentially show signs of poisoning.


Considering that the average chocolate bar contains 2-3 oz of milk chocolate, it would take 2-3 candy bars to produce toxicity in a 10 lb dog.  However, a single ounce of baking chocolate could produce severe toxicity in the same size dog.


So, how does chocolate make dogs sick?  Theobromine causes the release of
certain substances, norepinephrine and epinephrine, that cause an increase in the dog’s heart rate and can cause arrhythmias.   Other signs seen with chocolate toxicity can include increased urination, vomiting, diarrhea or hyperactivity within the first few hours.   This can lead to hyperthermia, muscle tremors, seizures, coma and even death.


What should be done if a dog does ingest a toxic amount of chocolate?  If it has
been less than 2 hours, the dog should be made to vomit.   Unfortunately, chocolate tends to form a ball in the stomach and may be difficult to remove. Supportive care should be provided for any other signs the dog is exhibiting.
Though it may not be harmful to the dog in small quantities, it is safer to avoid
giving chocolate to dogs in general.   As with everything else, it’s better to be safe than sorry.