There are people who swear by raw...there are others who won't do it...and there are some who have had sick dogs from it. I know of two who are YTers who won't post about their experiences because they want to avoid the arguments that they feel will come.
Bottom line is that it is not true that dogs don't get sick from salmonella. There are many who believe that all dog food has it, but I don't buy that. We do know that poultry is a source.....
Anyway...here is a link about IBD and it does specifically list salmonella as a possible source.
Inflammatory Bowel Disease
I don't know how common it might be .. don't know about any research about it. I just know it can make a dog very sick.
The only thing I know about corn is that some people's pets have allergies to it. I know of no other real health issues.
I feed my healthy pups kibble and they are fine. To each his own...we have to do what we feel is best for our pups.