My puppy won't eat her food!!! Help!?

My 11 Month old puppy hasn't eaten any of her food for 3 days. She hasn't been acting funny, and she hasn't eaten anything odd that i know of. But she has eaten a lot of grass this past week. She will only eat treats and bones. My family and I are worried about her,and we want to fix it. She is a Springer Spaniel 11 month old puppy. please help!!