Is Chocolate Really that Bad for Dogs?

By now, you’ve probably heard dogs should not eat chocolate. You may have heard stories of worried dog owners rushing sick, near-death pets to the emergency room; then again, you may have also heard owners laughing about their dogs eating entire bags of chocolate candy and being “fine.” While both of these stories are true, it underlines an important fact all veterinarians know: chocolate can be very dangerous for your dog.

First and foremost: dogs should not eat chocolate.

The toxic ingredient in chocolate is called theobromine. Compared to people, dogs metabolize theobromine very slowly. This makes even a small amount of chocolate potentially very dangerous for your dog. When consumed in chocolate, theobromine can cause gastrointestinal, heart and neurological problems, including: vomiting, diarrhea, hyperactivity, restlessness, muscle spasms, high blood pressure, heart arrhythmias, seizures, and potentially death.

It’s important to know that the toxic effects of chocolate are not all equal. The reason some dogs can eat chocolate with few side effects while others almost die is based on three factors: the type of chocolate, the weight of your dog, and the amount consumed. As seen in the chart below, theobromine content varies greatly among chocolate types. The theobromine content is expressed in milligrams per ounce of chocolate (mg/oz.). In short, the darker or more bitter the chocolate, the more theobromine it contains, and the more dangerous it is to your dog.

The weight of your dog and the amount of chocolate he eats determines the side effects that occur. Based on experience and research, the Animal Poison Control Center considers 100-200 milligrams of theobromine per kilogram of dog a lethal dose. Mild gastrointestinal symptoms can happen at doses as small as 20 mg/kg, and severe symptoms, such as cardiac arrhythmias and seizures, can occur at 40-60 mg/kg. Using these numbers, just 3 ounces of dark chocolate would cause GI problems for an average-sized, 50-lb retriever. On the other hand, the same 3 ounces of dark chocolate would be a lethal dose for a 10-lb Yorkie if not treated soon enough.

Symptoms of chocolate toxicity can take several hours to occur and can last several days due to theobromine’s slow metabolism. If you know or suspect your dog has eaten chocolate, please call a veterinarian immediately. The Animal Clinic of Woodruff can be reached at 864.576.9800 (find more Spartanburg area emergency vet contacts here). If a veterinarian is unreachable, call the Pet Poison Helpline at 855.764.7661 or the ASPCA Poison Control at 888.426.4435 for assistance (there are fees for either call). In cases where high or potentially fatal doses are ingested, prompt intervention is key to successful treatment.

So, this Valentine’s Day, don’t share your chocolates with the dog—and be sure to keep all treats out of reach. If you do suspect your dog has eaten any chocolate, don’t laugh it off—call your vet for advice or seek veterinary care immediately.