Cooking changes protein molecules in food (their shape for one, burgers that blow up with air in the middle when cooked is a good example) light cooking won't totally destroy them but will alter the proteins. Cooking also removes some essential vitamins, natural acids, and changes the actual composition of the meat. If you do cook all your dogs food then you are probably going to have to add the vits and mins lost with the cooking process in the way of supplements.

Dogs guts are shorter and their stomach acid is stronger than ours is, they're designed to eat raw food in the form of carcasses (either killed by themselves or scavenged from), their digestive system isn't any different from that of a wolf or a wild dog in africa or a dingo so it's set up to easily digest raw meat, they also process the 'germs' better than we do. Salmonella, e-coli, can also be found on kitchen sinks, fridges, the floor, back garden etc; most people forget this and only think that it is on raw meats.

Mars petcare this year had to recall in the USA Pedigree Complete Nutrition Small Crunchy Bites dog food on August 8th 2008 (Pet Food Recall issued by Pedigree: Salmonella a Risk with Complete Nutrition Small Crunchy Bites) there was also a recall of several different pet foods last year as one of the grain products was the cause of the problem.

Of course commercial dog food manufacturers will 'try' to convince people that their food is the best thing to give to your dog, they are a business they want to make a profit. Adverts will show happy healthy dogs (these dogs may or may not be fed on the food advertised), one example - Burns have a page dedicated as to why you shouldn't feed a dog raw food (I'll put a link in once I've found it again) but are now promoting a mixer to feed your dog with a raw diet, if the company can make you think that you 'need' this product then you are more likly to buy it so this new mixer is designed to make people who feed raw think - I 'need' to add this to my dogs diet otherwise it's missing out on something - think about the adverts and then about how you buy the product. There are no adverts on TV for raw feeding, canned food has only been around for (in the UK) the 1930's (I'll check for the exact date)or so and that was chappie (mars bought them out) so what were dogs fed before commercial food was available?