Chocolate contains a substance called theobromine. Caffeine & theobromine belong to a chemical class of alkaloids called methylated xanthines. These are found in coals, coffee, tea & in chocolate. As a class of drugs, Methylated xanthines cause central nervous system (CNS) stimulation, diuresis (flushing of fluids through the body), cardiac (heart) muscle stimulation, & smooth muscle stimulation.
Methylxanthines are absorbed very quickly & easily from the oral cavity & intestinal tract. The liver is needed to metabolize these chemicals, & the waste products are excreted in the urine. These chemicals primarily affect the CNS & kidneys. These chemicals cause increased motor activity & also result in tachycardia (too fast a heart beat.) Because of the increased motor activity, seizures may occur. The kidneys may be affected causing diuresis & very high urine output. This may lead to dehydration. Respirations may become too rapid, & hyperthermia (too high a body temperature) may occur, resulting in death. There is NO antidote for these drugs. We may only treat symptoms with supportive care & drugs to decrease their severity.
Toxic dosages for birds are not well established. In dogs the toxic dose is approximately 200 mg/kg of body weight. In cats the lethal dosage is only 80 to 150 mg/kg of body weight. (higer metabolism means that less is needed to cause toxic effects.) A cup of coffee may contain 35 to 85 mg. A 12 ounce bottle of cola contains approx 50 mg. Now these levels would mean that a 1 kg (2.2kg) cat would need to drink1 1/2 to 3 colas for death to occur. However, since a bird has a much higher metablolism than a cat, & a much smaller body size than a cat, we can safely say that it would take a much smaller dose for toxic effects & possibly death to occur.
Since we are unsure of the toxic dosages in birds, one definitely should avoid ALL caffeine & chocolate consumption for pet birds. (theobromeine & caffeine are both found in chocolate-- this means that chocolate packs a double whammy!) I reccommend that these substances be avoided in ALL pet species. I feel that my birds have enough energy as it is. Why rev their systems up even more???