There were some cases of people getting salmonella from pet food here recently . So no its not safe to eat. I not sure what FDA standards they follow. Remember China sent a bunch of poison over here last year to be added to dog food.
Pet food in not safe to eat. It has things in it that is not meant for human consumption. Its is ground up animal guts, skin and bone and only animals like dogs should eat it. Read the tin/bag of dog food and it should say not for human consumption. When I was younger I ate dog food, tasted like crap, don't try it!
I'm guessing you might have already tried it, every kid goes through wanting to taste it. But don't get addicted to it, some dog foods have serious bad stuff in them, even for dogs. Taste it then move on