Has she had any other symptoms like pawing her nose a lot or perhaps restlessness? Milk fever would come to mind, but am not entirely sure whether she would not want to eat much over it..... I would suggest if youre not very happy to ask vets advice, just in case. What is she like within herself? How is she going to the toilet? What is she being fed? When did she start to lose her appetite and have you noticed any other changes in her? Sorry for all the Q's, I would just like us to be able to get a bigger picture of what may be wrong.