In a dog the compounds are taken up by the liver
and transmitted via the bile into the intestine. They are then converted
back into the original methylxanthines for another circuit through
the animal. This repeats itself a number of times and instead of
getting rid of the substances the dog keeps repoisoning itself-
There are many formulations of chocolate with varying
amounts of caffeine and theobromine. The lethal dose of sweet milk
chocolate for a dog is 2 oz per kilogram of bodyweight. For a 5
kilogram dog this would be about 280 grams. A lethal dose of milk
chocolate for a 25 kilogram would be about 1.4 kilograms.
Dark chocolate is at least 10 times as lethal. A
25 kilograms dog could die from the methylxanthines in 5 ounces.
Symptoms include vomiting, hyperactivity, restlessness,
hypersensitivity to touch ( a dog will jump when touched very rapid
heartbeat and rapid breathing rate. A loss of control of leg muscles,
muscle tremor seizures, general weakness, coma and finally death
follow.
In my opinion it would be a tragic mistake to encourage
a dog to develop a taste for chocolate. A small dog left alone in
a house with a box of chocolates might well follow his nose to the
goodies and commit suicide by poisoning.