My 5 year old border collie is a rescue dog we have had him for 2 years. He is great except when the door bell rings or the smoke alarm goes off he will attack the doors. I now have 3 badly chewed doors and would like to cure this before we replace the doors. Any ideas on how we can deal with this?

Sounds like he has some serious fear issues. I would suggest finding ways to buikld his confidence and maybe even look into some behavior modification classes. You can also try having your dog sit beside you, and have some one knock on the door, or ring the bell, when he starts barking and going crazy put him on his leash, and ask him to sit, the minute he sits reward with praise and a treat. Keep trying to distract him with either treats or praise. Keep practicing this, and soon he will realize what behavior you are asking from him.

Sounds like he could use a little more work on basic commands. If you say "no" and as him to "come" he should stop what he is doing and respond. So really start working on the basics again, taking him to the park, working on his recall and stay commands. Get a friend or your partner to come, get something that would make a loud distracting noise, and when your dog is re acting towards that noise, start with the "stop" and than ask him to "come" and than "sit" praising and treating for each command he does.