Crate training & anxiety

Question
Labman, I recently adopted a yellow lab from a shelter that is 4 months old.  He is pretty well housetrained, smart, quiet, and well behaved as long as I am home.  I have kept him in a crate for the last week while at night and when I am at work.  He does not mind the crate when I am home, but becomes completely panicked the second he knows that I left the apartment during the day (banging, barking, yelping loudly).  The behavior continues for at least the 45 minuted that my tape records.  I leave music on, leave the cong, and come and go with no fuss.  These do not alleviate the anxiety.  I have heard of spray & electronic collars, scents, and someone even suggested a muzzle.  I would like to avoid any inhumane practices.  Nevertheless, it is essential for the dog that his anxiety is lessened, while it is important to me that the neighbors aren't driven crazy for the entire day! Any suggestions?  Thanks, Matt

Answer
Being left alone is not a natural thing for a dog.  This is a tough problem to fix.  If you haven't, try filling the Kong with peanut butter.  With the food motivation of a Lab, he will so busy licking the peanut butter out, he will hardly notice you left.  Freezing it may make it last longer.  

I hate to suggest it, but if that doesn't make enough difference, you may need to talk to the vet about medication.  I would rather see that, than some of the others ideas.