It turns out that it all comes down to biochemistry. The problem with dogs and chocolate stems from two facts:
- Dogs love chocolate because they have a sweet tooth.
- Chocolate contains a compound called theobromine.
Theobromine is a chemical compound that is metabolized (i.e. changed) into a chemical called xanthine in the dog’s liver.
And xanthine is bad for dogs. Why? Because xanthine interferes with very important phosphodiesterase inhibitors (a special class of cell enzymes), leading to:
- increased heart rate
- increased central nervous system activity
Left unchecked, this increased heart rate or the overload of activity in a dog’s brain can be deadly.
The excess vomiting, urination, and diarrhea of a dog after eating chocolate is actually a safety mechanism to try and purge the dog’s body of the toxic buildup. This also helps explain how coffee is bad for dogs, since the biological breakdown of caffeine produces theobromine as well.