Aggressive Cocker Spaniel just bit another person!

Question
My brother's 6 year old male cocker was a pet store purchase as a puppy.  He
has always been a high anxiety dog, especially in new situations and around
new people in his home.  He has bitten several people, but luckily no one has
pursued any damages.  He just bit a boy that was going door to door for
donations and my brother has decided he is going to have him put down.  I
know it isn't the dog's fault, but my brother is afraid the next time will be
worse ( I have a 6 month old daughter, so I too am concerned) but I need to
offer him a better solution.  The dog has no health issues and passed
obedience training with flying colors.  He is a great pet, but is aggressive to
strangers, mainly just when he is 'protecting' his home.

Answer
Hi Laura,
I gather that your brother has never addressed this through training?
I don't mean obedience class, I mean specific one-on-one training to address this "intruder-aggression"?

To quickly answer your main question.  Yes, this can be fixed but I'd like to talk to you at length about this so suggest, for speed & convenience, you write me directly at DeeBeck7765@aol.com.

The dog just thinks he's doing his job by protecting his family but obviously since he's not just barking but has bitten, this has to stop.  

How is he on walks?  Outside his home?  At the vet's?

In the meantime, your brother can take steps to prevent this by leashing/crating and not allowing the situation
to happen.
Delores