Theobromine 101: Why Chocolate is Toxic
Unlike humans, dogs cannot efficiently metabolize Theobromine and Caffeine, both found in cacao. These chemicals act as powerful stimulants that can over-activate a dog's central nervous system and heart muscle.
Toxicity Concentration by Type
Not all chocolate is created equal. The darker and more bitter the chocolate, the higher the concentration of theobromine:
- White Chocolate: Negligible amounts of theobromine (mostly sugar and fat).
- Milk Chocolate: Moderate amounts; risk depends heavily on dog size.
- Dark/Semi-Sweet: High danger; small amounts can be toxic to large dogs.
- Baking Chocolate/Cocoa: Extreme danger; very small amounts are often medical emergencies.
"Rex," a 50 lb Golden Retriever, ate a 4 oz bar of unsweetened Baking
Chocolate.
- The Math: Baking chocolate contains ~390mg of theobromine per ounce. 4oz
= 1,560mg.
- Toxicity Dose: 1,560mg / 22.7kg = 68 mg/kg.
- The Result: This is firmly in the Severe Toxicity range.
Rex required immediate veterinary intervention (IV fluids and heart monitoring) to prevent
life-threatening seizures.
Emergency Symptom Tracker (2-6 Hours)
Look for extreme restlessness, pacing, panting, and a rigid abdomen. Vomiting and diarrhea often follow as the body attempts to purge the toxins.
If the calculator shows Moderate or Severe risk, call a vet immediately. If it's Mild, monitor closely and call if you notice any changes in heart rate or breathing.