Chocolate poisoning in dogs is determined by the chocolate toxicity severity, which varies with the size of the animal and the concentration and amount of the chocolate. The main symptoms include vomiting, diarrhea, heart arrhythmias, excessive drinking and/or urination, hyperexcitability, lethargy, racing heart rate, seizures and even death. Usually the darker the chocolate (especially baking chocolate), the larger the amount eaten, and the smaller the dog, the more severe the problem. Early intervention greatly increases the prognosis for recovery.
Here is a very cursory Rule of Thumb for Chocolate Toxicity. This should not replace consultation with your veterinarian in the event of known or suspected exposure, and not all dogs will follow this rule exactly, but it can give some general guidelines to follow.
Rule of Thumb for Chocolate Toxicity
Chocolate contains theobromine that is toxic to dogs in sufficient quantities. This is a xanthine compound in the same family of caffeine, and theophylline.
It takes, on average, a fairly large amount of theobromine (100-150 mg/kg) to cause a toxic reaction. There are variables to consider like the individual sensitivity, animal size and chocolate concentration.
- On average, milk chocolate contains 44 mg of theobromine per oz.
- Semisweet chocolate contains 150mg/oz. of theobromine per oz.
- Baker’s chocolate 390mg/oz. of theobromine per oz.
Using a dose of 100 mg/kg as the toxic dose it comes out roughly as:
- 1 ounce per 1 pound of body weight for milk chocolate
- 1 ounce per 3 pounds of body weight for semisweet chocolate
- 1 ounce per 9 pounds of body weight for Baker’s chocolate
So, for example, 2 oz. of Baker’s chocolate can cause great risk to a 15 lb. dog; yet, 2 oz. of milk chocolate usually will only cause digestive problems.
Clinical Signs of Chocolate Toxicity
Xanthines affect the nervous system, cardiovascular system and peripheral nerves. It has a diuretic effect as well. Clinical signs may include:
- Increased heart rate
- Increased urination
- Muscle tremors
Treatment for Chocolate Toxicity in Pets
There is no specific antidote for this poisoning. And the half-life of the toxin is 17.5 hours in dogs. Induce vomiting in the first 1-2 hours if the quantity is unknown. Administering activated charcoal may inhibit absorption of the toxin. An anticonvulsant might be indicated if neurological signs are present and needs to be controlled. Oxygen therapy, intravenous medications, and fluids might be needed to protect the heart.
Milk chocolate will often cause diarrhea 12-24 hours after ingestion. This should be treated symptomatically (fluids, etc..) to prevent dehydration.