I adopted a new 5yo pup and had purchased Natural Balance Lamb and brown rice which he didn't seem to be interested in... I added a tiny bit of cut up chicken breast and he ate it. My husband went out an purchased the chicken and rice version of Natural Balance and mixed it in the food container where I had the lamb and rice. Is it safe to do this? If I have to, I will go through and separate it by hand as I do not want to hurt my new little 10 pound pup.