In my opinion, everyone should eat as raw as possible.
But as UncleSilas has pointed out, much of the farmed food of our age simply shouldn't be eaten raw (or even at all) because of all the polluting agents in it. Honestly; if you look at the chemical substances found in our food, germs and parasites are the LEAST of our worries...
Edit: Unlike humans, dogs are actually mostly scavengers. They would let much of their kills rot before they eat it (which is also why they bury prey) to make it more easily digestible. Fresh raw meat is fine every now and then (though I'd advise against poultry or pork), but on the whole... I'd feed them processed (because rot stinks).