What Makes Chocolate Poisonous to Dogs?

Chocolate is made from cocoa, and cocoa beans contain caffeine and a related chemical compound called theobromine, which is the real danger.

The problem is that dogs metabolize theobromine much more slowly than humans, reported by Denver veterinarian Kevin Fitzgerald, PhD, tells WebMD.

“The buzz we get from eating chocolate may last 20 to 40 minutes, but for dogs it lasts many hours,” he says. “After 17 hours, half of the theobromine a dog has ingested is still in the system.”

Theobromine is also toxic to cats, but there are very few reported cases of theobromine poisoning in felines because they rarely eat chocolate.

Dogs, on the other hand, will eat just about anything.

Even small amounts of chocolate can cause vomiting and diarrhea in dogs. Truly toxic amounts can induce hyperactivity, tremors, high blood pressure, a rapid heart rate, seizures, respiratory failure, and cardiac arrest.