I have a 7 month old female chihuahua puppy. She was off to a rough start and we spent over 1000 dollars in vet bills. She is now happy and healthy but she is very skinny. She is about 2.3 lbs, boney and her ribs show all the time. We feed her Iams puppy toy breed dog food at least twice a day but sometimes she wont eat it. I had her checked with the vet and she is parasite free and seems to be healthy otherwise. I am not sure what to do.