Damaged Beyond Repair?

On occasion in rescue, and maybe more than I care to admit, I get discouraged and just down right mad.  Tonight as I write I am sad and very angry.  Being involved in dog rescue and able to foster means that often I have "extra" house guests around.  One of the rescues I foster for asked me to foster a Papillon that was originally a stray at a high-kill shelter.  He was pulled by a rescue and then the rescue that I am involved with took him.  From there he was adopted very briefly by a family that was very excited about him, however he showed some aggressive behaviour and was returned to the rescue.  After working with him for a bit longer, he was adopted out another family.  Again, he came back after exhibiting aggressive behaviour.  So now we are at a cross road.... 

The general rule in rescue is that dogs that are aggressive are euthanized because the rescue is responsible for the dog if it bites someone, especially if the dog had a known aggression problem at the time of adoption.  However difficult this may be, it just doesn't make sense to ever endanger someone's child, family, or home with a dog who is a known biter.  I understand this, and usually agree with it.

The only time this really bothers me is when it is evident that the dog in question has been damaged beyond repair by a human.  I believe this is the case with Pip.  This little dog is truly a Papillon.  He is smart, funny, bouncy, and true to this breed's nature: a very delightful and charming little dog.  The problem?!  Some jerk, somewhere in this poor creature's life has broken his spirit and he has NO reason to trust anyone.  Bottom line:  This dog is afraid, and he is using his teeth to put on a show.  When he is afraid, he bites, which makes people leave him alone.  He accomplishes his mission: to never be hurt again.  Unfortunately  Pip doesn't speak our language.  He doesn't understand that he is safe, has people that only want to help him, and he will never be hurt again.  (I have told him several times tonight and my rescue friends have mentioned this to him as well!)  So the question remains: What do we do with this little dog?  Do you take the chance that he will bite again?  Do you euthanize him because he is a known bite case?  

After spending the day with Pip, I am hoping that there will be some hope for him.  He is eager to please his humans.  He is food motivated, and he appears very forgiving.  He has spent his entire day in his crate because that is where he wants to be.  He has NO confidence and is scared of everything!  I attempted to lure him out of his cage with a little garlic sprinkled chicken, and that worked briefly.  Today in his training session we accomplished "charging" the clicker, and worked on sit.  We will see what the future holds for this little guy.  I hope and pray that it is all good!  I will keep you all posted!