I’m not sure it is a scientific reason, but some believe that raw digests faster than kibble causing raw to sit in the stomach longer possibly making it more likely for the body to pick up bacteria from the raw food.
However, this belief is becoming less common these days. Take a look at this link: http://www.therawfeedingcommunity.com
I feed my dogs raw tripe or commercial raw nuggets mixed in their kibble in all their afternoon meals with no issue.
I also mix canned into all their morning meals with no problems.
I hope this helps!
