There are people who love chocolate so much that the humorous phrase “death by chocolate” might apply to their appetites.

But the sweet stuff can literally mean curtains for your dog.

If your sweet-toothed canine has helped himself to a sweet treat, it could mean a stomachache or worse, says Dr. Melanie Landis, a veterinarian at the College of Veterinary Medicine and Biomedical Sciences, Texas A&M University.

“Chocolate contains a chemical called theobromine which is toxic to dogs,” says Landis. “If ingested in large quantities, theobromine can stimulate the nervous system and cause irregularities in heart function.”

When theobromine levels are considered, not all chocolates are created equal. Different types of chocolate contain varying concentrations of theobromine.

“Dark and baking chocolates have the highest concentrations and should be strictly avoided,” Landis warns. “Even in small amounts, these chocolates can be toxic.”

With any cocoa concoction in his system, your dog may display hyperactive behavior much like you do after losing count of how many chocolate peanut butter cups you’ve eaten. Unlike your own episodes, your dog’s hyperactivity can elevate to tremors and even seizures, especially if dark or baking chocolate is your dog’s dessert of choice, says Landis.

When your dog finally comes down from his chocolate high, he may be feeling pretty low.

“It is typical for chocolate to upset your dog’s gastrointestinal system, causing nausea, vomiting and diarrhea,” Landis says. “These signs usually appear two to four hours after the dog ingests chocolate.”

If your dog shows any of these signs or if you suspect he has sampled a bite-size candy bar or two (a pile of partially chewed wrappers is a good indicator), contact your veterinarian.

“Your veterinarian can recommend the best course of action based on the size of your dog and how much chocolate it has eaten,” Landis says.

In some cases, your veterinarian may be able to stop the effects before they even start.

“If the animal is treated within one to two hours of ingestion, the veterinarian may administer activated charcoal or an emetic to slow absorption of theobromine,” she says. But, if more than two hours have passed, there are still plenty of other ways to care for your pet.

Most mild cases can be treated with what is called supportive care.

“Be sure the dog is hydrated, and keep its electrolytes balanced,” Landis suggests. “Within 24 to 48 hours, it should be feeling better.”

Landis also recommends feeding your dog a bland diet for a few days to avoid further upsetting its stomach. For more severe cases, where the animal is vomiting excessively, your veterinarian may administer an anti-emetic medication.

“If your dog has lost a lot of water through vomiting and diarrhea, it may need to be hospitalized and given IV fluid to correct its electrolyte balance,” Landis advises.