I have a 4 month old German rottweiler puppy who has a very dull coat and is not very energetic. I want to switch to an organic/natural dog food but I also want it to be for large breeds (to keep up with her growth). Help! I do not know what to get! I have been feeding Science Diet Large Breed Lamb and Rice, but she doesn’t like it and it hasn’t helped with the coat. Am at my wits end.