Do you put a biting dog down?

Question
My question is should my friend put his 12 year old Chow lab mix down after the dog bit him severely.

My friend was standing in front of his dog, dog looking right at him, offering him a treat.  The dog aggressively grabbed the treat out of his owners hand.  This is not normal behavior for his dog.  The dog is normally submissive and waits to be given the treat and takes it gently. My friend took the treat back from the dog and this time the dog bit him three or four times on the hand.  My friends hand was bleeding rather steadily.  If the 4 main cuts were any wider then my friend would have needed stitches.  My friend immediately pinned the dog on the floor and kept the dog's mouth open showing his dominance until the dog stopped growling and showing aggression.

Several times during that same night the dog showed signs of aggression through out the evening.  My friend would firmly tell the dog to lie down and the dog would growl through the muzzle.  He had to pin the dog again that same night.

The dog has bitten my friend once before, but he felt it was due to stress of the move.  The dog bit through his thumb nail. My friend fears that the dog will only get worse especially since he showed signs of aggression towards his owner.



I'm not sure if this is enough information for you to give your professional opinion on this matter.  If you could give your brief opinion and any reference sites on this matter that would be greatly appreciated.

Connie R.
Albany, OR


Answer
Hi Connie,  First off, your friend should never have pinned the dog down after the dog showed aggression, especially a dominant breed like a chow.  When you try to dominate a dominate dog, all you do is end up butting heads and making matters worse.  Same goes for putting a muzzle on.  The way to make a dog bite is to put a muzzle on them.  Thats how you train a dog to give a solid bite, is to put a muzzle on them, aggravate them, and then take the muzzle off.  They will bite even harder.  
At this point your friend has probably destroyed the trust of the dog.  The dog is 12 years old.  Compare that to human years and the dog would be 84 to 90 years old.  What probably was happening is that the dog is losing his senses (like seeing & smell) and overreacted to the treat.  Your friend overreacted and made the situation ten times worse.  At this point he needs to work on gaining the trust of this dog again.  It is going to take some time as he has majorly traumatized him.  Think about if the dog was a human, was that age (your grandfather) and overreacted to something.  Reacting in that manner would majorly traumatize him.  Again, your friend needs to work on gaining the dog's trust.  It won't be easy at that age.  Wish I could be of more help, but this all lies now in your friend's hands in being patient with the dog and understanding the dog is old and possibly losing its' senses as well as possibly also going a little senile.

Dawn