Toxicity The
median lethal dose (LD50) of theobromine has only been published for cats, dogs, rats, and mice; these differ by a factor of 6 across species. Serious poisoning happens more frequently in animals, which
metabolize theobromine much more slowly than humans, and can easily consume enough chocolate to cause poisoning. The most common victims of theobromine poisoning are
dogs, for whom it can be fatal. The toxic dose for
cats is even lower than for dogs. However, cats are less prone to eating chocolate since they are
unable to taste sweetness. Theobromine is less toxic to rats and mice, who all have an LD50 of about . In dogs, the biological half-life of theobromine is 17.5 hours; in severe cases, clinical symptoms of theobromine poisoning can persist for 72 hours. Medical treatment performed by a
veterinarian involves inducing
vomiting within two hours of ingestion and administration of
benzodiazepines or
barbiturates for seizures,
antiarrhythmics for
heart arrhythmias, and
fluid diuresis. Theobromine is also suspected to induce
right atrial cardiomyopathy after long term exposure at levels equivalent to approximately of dark chocolate per day. According to the
Merck Veterinary Manual, baker's chocolate of approximately of a dog's body weight is sufficient to cause symptoms of toxicity. For example, of baker's chocolate would be enough to produce mild symptoms in a dog, while a 25% cacao chocolate bar (like milk chocolate) would be only 25% as toxic as the same dose of baker's chocolate. One ounce of milk chocolate per pound of body weight () is a potentially lethal dose in dogs.
Pest control In previous research, the
USDA investigated the possible use of theobromine as a toxicant to control
coyotes preying on
livestock. ==See also==