boxer misbehavior

Question
I have a boxer that I adopted around 9 months ago that doesn't seem trainable.  I'm his 3rd home in his short life of less than 2 years.  He has had occassions of escaping from his box while I am gone and destroying everything in sight, he has even chewed on door jams!  He had initial issues with peeing on the floor, however, was doing better with that.  Now, for the last 2 weeks he has had 2 separate accidents where he left a urine trail across 2 different rooms.  He doesn't listen very well, when you tell him to come, he doesn't listen.

I'm not sure what to do with him at all.  I have tried the training with the treats and got him to be able to sit.  Like I mentioned before, he was doing well with the bathroom training but has reverted.  He gets alot of attention, affection, and there is usually someone home with him to let him go in and out as often as he needs.

It used to be that his downfall was the trash can, however, he will also try to eat anything he can reach.  So, of course, I try to prevent an issue with this, however, if he gets any opportunity he will take it.

I have had dogs my entire life and have never had a dog that refused or seemed uncapable of training.  

Not really sure what I should do with him?  He is very affectionate with my children but sometimes the negatives seem to outweight the positives of him.

I don't want to give up on him but am at a loss.

Any help you can offer would be great.

Answer
Hi Mel,

You have trained your Boxer to sit, so he's not really untrainable. :)  If he's not coming when you tell him to, he just doesn't know what "come" means.  (Remember English is a foreign language to dogs. :)  An American wont' know what "bonjour" means until someone teaches them it means "hello".)  

Boxers are different than many other breeds; they are highly intelligent and independent thinkers, and so 'traditional' training methods tend to be less effective for them.  Methods which let the dog think for itself and problem-solve, as it were, generally tend to have much higher rates of success for Boxers.  (The most common type of this sort of training is clicker training - there are many websites which give quite a lot of detail on clicker training, how to work on various behaviors, etc.  Just a few are:
http://www.clickersolutions.com
http://www.clickertraining.com
http://www.clickertraining.biz

There is also a good step-by-step process available at
http://www.dragonflyllama.com/%20DOGS/%20Dog1/levels.html

You might benefit from an obedience course, as well, the real point of which is to teach you to teach your dog; there is a listing of clicker teachers here:
http://www.clickerteachers.net

The other behavior - inappropriate urination, destruction, chewing on door jambs - sounds like separation anxiety.  (Not surprising, given his experience with rehoming.)  There are some training exercises you can do to minimize this - a few suggestions are here:
http://www.clickertraining.com/node/1556

As well, be sure he's getting plenty of exercise before you leave, and give him something to do while you're gone - a stuffed Kong is often a great choice, as it's a bit of a puzzle to exercise his mind, and it's food so is highly appealing. :)  More information on Kongs and how to stuff them is at http://www.kongcompany.com

Good luck!

~Jennifer