My 20 Month Old -13 Lb Female Shih Tzu Has Always Been A Picky Eater. Recently We Gave Her A Beef Hot Dog... she Won't Eat Anything Else. I Give Her 2 Hot Dogs At Noon & 2 At 6pm... she Lovvvvvvvvves Them & Is Happy As Can Be. Am I Feeding Her Too Much & Is She Getting Proper Nutrition? Thank You