I am so sorry. This is a heartbreaking moment that I remember too. Feelings
of dread & helplessness at the moment seem to flood your soul.

If you can imagine Scruff talking to you, as only a dear friend would do, he
might say that he does understand your pain at parting from him. It is indeed
the hardest thing to say goodbye to a best buddy. (((Hugs))) Be at peace
with whatever you decide to do, for it will be the only kindly & loving thing
you are able to do for him. (((Hugs))) & prayers for you and for Scruff.

http://www.petloss.com/poems/maingrp/lastbatt.htm