Suggestions Please

Somebody already suggested Taste of the Wild, but as far as I can tell it only comes in 30 lb. bags and there is no large breed formula.  

 

We have always fed our dogs Chicken Soup Large Breed Adult. Lately they haven't wanted it and the dogs have had diarrhea off and on for the past few weeks. Yesterday our 9 month old Belle started vomiting everytime she ate and had diarreah, this lasted for about 24 hours. She would not eat, but would drink plenty. She started eating again, but it was hamburger not her dog food, and she acts perfectly normal. My vet was kept up to speed on the problem and has declared her in good health. Has anyone else had this occur with any food?