Hi Lisa, I recently took my Trent in for adrenal surgery and biopsies, and in the process my vet found a very large hairball. It was so large, in fact, that she had to make an incision in the stomach to remove it. Other than weightloss, which we attributed to the adrenal gland issue, Trent had shown no signs of a hairball, so it's possible that this is what's going on with your sweet Hagen. Good luck! angie [Posted in FML issue 4395]