^Trevor. Your logic is flawed.
For a start: women already HAVE oestrogen. The soy acts as a top-up, and is such a tiny amount that it is of absolutely no consequence if ingested by a male.
Secondly: 1.5-2 grams of protien per pound of body mass is unhealthy. It's broscience to suggest a person needs more than 1 gram (and ideally .8 of a gram) per pound of lean body mass, no matter what athletic condition they are in.
Thirdly: most dogs and cats DON'T actually survive on a diet of pure protein. Your average dog and cat food is at least 50% vegetable matter... which is why kept, domesticated cats live much longer than ferals.
Incidentally, the length of a dogs intestines - proportionate to their 'mouth-to-anus' ratio, as you put it - is 5% that of a human's.
But on dentition alone, your points are disproven: both dogs and cats have solely flesh-tearing teeth (canines, not to be too obvious) while humans have vegetable-crushing teeth (molars). Also, dogs and cats cannot manipulate their jaws from side to side, like humans and other herbivores (cows, for instance).
In short, the similarities between humans and any carnivore you might like to mention are far outweighed by the differences, rendering the comparison obsolete.
EDIT: and a final thought - in reality legumes etc do little to no damage at all to the human digestive system (if eaten as part of a balanced diet, of course) Now overcooked or overly aged meat... very different story!
Last edited by Abaddon; 01-14-2011 at 12:48 PM.