In response to pyrless with the food-aggressive dog:
I also have a food-aggressive dog. He is fed separately from my other two dogs. I was told that he came from a home with two dogs that did not like him and kept stealing his food.
I just know, as everyone in my house does, that you don't go near him while he's eating. But isn't that what we've always heard anyway, not to bother a dog while he's eating or sleeping.
I will say that I have a lab/border collie mix and I could stick my entire face in his bowl and he would just eat around my face. :)
All three of my dogs have issues of their own and I always say that if other people owned my dogs they may have wound up back at a shelter, and that none of them would be adopted out according to what I see on those animal cops shows.