Guys, I feel this is very important - yes kibble and raw do not digest at the same rate. But, so what right? Well, here's WHY you wouldn't want to do this to a dog like an English Bulldog who is already health-compromised (we all agree on this, right?).
The reason why dogs can eat garbage and not get sick is because a dog has an acidic digestive flora and a short digestive tract. So, bacteria that enters the mouth would either not survive the digestive flora or, if they do survive, they get excreted before they can set up beachfront condominiums and have babies.
Now, raw meat, as we all know, is susceptible to all kinds of bacteria. That's why we humans have to cook our meat before we eat it. A dog eating raw meat can get that bacteria passed through lickity split if it doesn't die in the acidic environment because a dog is super efficient in digesting raw meat proteins. But the risk of bacterial infection rises when kibble is in the dog's body. Kibble is processed differently by the dog's digestive system. First of all, a dog's body notices the different composition of kibble and produces what it feels is the right amount of enzymes to digest it. The composition of kibble causes the dog to digest the food slowly through the digestive system (not as efficiently). Now, when you add raw meat to this soup, all that bacteria that are hitchhiking on that meat gets to stay in the dog's body longer giving the bacteria an opportunity to take out a mortgage loan and spend Valentine's Day with the wife. And, not only that, the relatively high carbs and sugar content of the breaded kibble is perfect All-You-Can-Eat-Buffet for bacteria so they have everything they need to party. So, the dog gets sick.
A lot of dogs get sick and then sends an anti-bacteria army of 300 warriors to defend their country so they come out just fine. Sometimes without getting any noticeable symptoms or even just a loose stool here and there. But, you know how we are so crazy about the health and well-being of our little cutie-pies that we do this stuff like agonizing over the vitamin content of their bowls or if we gave them enough salmon oil or if we needed apple cider vinegar, etc. etc... I just don't see a single justification for mixing raw and kibble good enough to put our babies at risk.
Just my 2 centavos...