Jack Russell Agression

Question
Hi,
We have had our Jack Russell, Bam, since he was 6 weeks.  He is now 1 1/2 years old.  He has shown agression only twice. Both times he was punished and put into his cage.  My husband actually scolded him. When he put Bam into the cage, he began growling and showing his teeth at him.
The latest time was my husbands last straw and has completely stopped having anything to do with him.  Let me tell you what happened.  I was not an actual witness but here goes.  My son was leaving the house and Bam ran for the door.  My son  held his foot out to stop him.  He said Bam began growling and showing his teeth, which he hasn't done before.  My son thought he may have been bit by something to cause his behavior.  He called my husband.  My husband came and told him "no" and put him in his cage.  This is when he began growling and showing his teeth.  My husband went to pull him out of the cage to get him to stop growling and Bam bit him.  He "punished" him and put him outside, where he remains today - 1 week later.  He normally stays outside during the day and comes in at night.  Now he stays outside 24/7.  What could have happened?  What can I do?  He has been to basic obedience class.  Up until now he has just been a typical Jack Russell.  I'm don't think I can get my husband to try again.  He wants to get rid of him, but he's my baby.  I will try anything.  My husband said "I" can keep him, but he will not have anything to do with him and he can't come into the house.  I'm not sure it's fair to Bam.  I need an outsiders help.
Thanks for trying to help us.
Jackie

Answer
 It sounds like he has finally come into himself.  Has become the dominate one in the "pack".  With this breed you HAVE to maintain the alfa role.  Its not too late to correct this.  Find a trainer that doesn't use possitive training but one that uses traditional methods.  But in doing so EVERYONE in the family MUST be a part of the training in order to have the dog knows his place in the "pack".  
 Also looking at he may be frustrated and taking out on the pack.  If you are stuck outside with nothing to do then that could be frustrating.  Try agility, earthdog or walks in park.  This breed needs outlets.  

Hope this helps some.

Tammy