Phish,
This thread is chock full of opinions on whether you should kill your dog or give it away or lock it in the laundry room or whatever. Only you can decide what you are going to do with the dog and I will not presume to give you advice on this matter. If however you do decide to do the deed yourself, please do not shoot him in the face. Feel with your fingers for the point at the base of the skull where the spinal collumn enters the cranium. Place the muzzle of a small calliber gun in contact with this point and squeeze the trigger. The dog will never know what happened and the mess will be very minimal.I speak from experience on this. I have had the unpleasant responsibility of putting down a number of dogs over the years.
Hope this helps and also hope the boy feels better soon.
Grumpyr