german shepard weight

Question
My 7 month old gsd bitch seems small to me she weighs 21kg and seems quite short in the leg but long in the back.  She has a poor appetite and eats very little the vet seems  unconcerned as she is healthy in every other way. Is she underweight and  if so is there anything i could feed her to build her up.  At the moment she measures about 18-19 inches to the top of her shoulder.  At what age will she be her full size. I have never owend a german shepard before so have nothing to compare her to.  Thank you, Theresa Shanahan.

Answer
It is quite common for a young Shepherd to refuse to eat enough to be more than quite thin.  As long as most of her calories are coming from a decent dry kibble, I wouldn't worry.  The only thing I would suggest is switching to an adult chow if you are still feeding a puppy chow.  That slows growth allowing more time to develop sturdy joints.  You can evaluate her using this link, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx  Likely she will come out on the thin side.  That is normal for a young shepherd.  

She should already be nearing her adult size.  She will continue to grow to at least a year, but hardly enough to tell.  I once had a thin little Shepherd.  The dog guide school she belonged to kept her as breeding stock.