Chocolate contains theobromine and caffeine, both toxic to dogs.
Dogs metabolize theobromine much more slowly than humans. Dark and baking chocolate are the most dangerous.
Chocolate contains theobromine and caffeine, both methylxanthine compounds. Dogs metabolize theobromine approximately 6 times slower than humans (half-life of ~17.5 hours vs ~2-3 hours in humans). This means even moderate amounts accumulate to dangerous levels. Theobromine stimulates the central nervous system and cardiovascular system, causing rapid heart rate, tremors, and in severe cases, seizures. Dark chocolate and cocoa powder contain the highest concentrations — up to 130-450mg theobromine per ounce — while milk chocolate contains around 44-60mg per ounce.
Sources
Mild symptoms (vomiting, diarrhea) can occur at 20mg theobromine per kg of body weight. Cardiac effects begin at 40-50mg/kg. Seizures occur around 60mg/kg. The lethal dose is approximately 100-200mg/kg. For a 10kg dog, just 30g of dark chocolate (about 1 ounce) could cause serious symptoms. A full bar of dark chocolate could be fatal for a small dog.
Contact your veterinarian or an emergency animal poison hotline immediately. Do not induce vomiting unless instructed by a vet.
callFind Emergency Vet