My new Border Terrier pup has been home for 5 days now but does not seem interested in food. She has been to the vets and he wasnt concerned as she has put 200 grams on in the 5 days I have had her. She doesnt get excited about food be it a treat or her main meal. When she gets her main meal she will eat a small portion then walked away, maybe sniff a toy , then return to make a token effort to eat, most of the time the food is binned. Should I be concerned and will she grow out of this?