interesting article from "newscientist" - does it also apply to Cats?

Question
I have read that dogs should not be fed chocolate because it is
poisonous to them. Is this correct, and if so, what are the differences
between canine and human digestive processes? And what are the
chocolate drops that you can buy for dogs really made of?

N. McDonnell , Ightham, Kent, UK

Answer
It is true that chocolate is poisonous to dogs. The problem is that
chocolate contains cocoa, which in turn contains methylxanthines. These
chemicals, which act on blood vessels, include theobromine,
theophylline and caffeine. They are responsible for the "kick" we get
from coffee, tea and chocolate.

The reason why dogs react differently to chocolate lies in their liver
enzymes. In dogs, breakdown of the methylxanthines takes a long time.
For example, theobromine takes about four days to be cleared from a
dog's system. It affects the heart, central nervous system and kidneys,
and even a small dose can kill a dog in as little as six hours. The
amount of chocolate that proves toxic varies, depending on the amount
of cocoa used in the recipe, as well as variations in individual dogs
themselves.

Many fatalities have been reported following ingestion of as little as
5 grams per kilogram of bodyweight. Medical records show that two
English bulldogs died after eating about 25 grams of dark chocolate
each, and a springer spaniel died after eating around a kilogram of
milk chocolate. Others have died after eating cooking chocolate, cocoa
powder and cocoa-based garden mulch ­ as single doses or repeated
exposure to smaller doses.

The only safe option is not to give human chocolate to dogs. Doggy
chocs are available in pet shops, marketed as "chocolate substitutes"
that are safe for dogs. They contain either no cocoa, or very little.
Check the ingredients with care; if you would prefer to give your pet
no cocoa, choose one of the many cocoa-free options. After all, dogs
are carnivores and there isn't any chocolate in the average carcass.