This is me first time raising/having chickens and one of my chicks has a runny diarrhea. They are on the chick starter/grower from nutrena and have been since the first day. We have not changed anything as far as their brooder/living quarters since we first brought them home. Is there something I can do to try and clear it up? Should we get the medicated feed instead?? They are all growing like weeds and eating a lot and gaining plenty of weight. Any advice would be appreciated!! Thank You!!!