[Franki D. Williams]

Franki D. Williams  asked the Naked Scientists:
   
Why cant dogs eat chocolate? They can eat everything else, dead or alive and be fine.

Franki

New Mexico, US.
What do you think?

[atrox]

Hi Franki,

the toxic substance in chocolade is called theobromine.
In humans this substance is digested quite rapidly in the liver due to a certain enzyme of the Cytochrome P450 complex.
In dogs and other animals (cats, bears..) these enzymes are much less active and it takes upt to 3 times longer to digest the substance. Consequently theobromine is accumulating in the organism much faster than it can be digested, leading to high blood pressure as well as a lower limen in nerve cells. In the end the failure of the heart or the lungs lead to death.
How dangerous chocolade is for dogs also depends on the type of chocolade with darker types being more toxic as they contain more theobromine.

So the dogs up to ten times more aggressive gastric acid in comparison to humans does not help them in this case, as it is enzymes that break down theobromine.

all the best
Aj