My sons siberian husky had severe seperation anxiety when he first brought her home, the reason I believe was because she was in a sled dog kennel with lots of other dogs,and now she was alone while they were at work, she was 1 1/2 yrs old when they got her, cuz they didn't want to deal with puppy training issues. She did destroy alot of things including 2 crates, so he called the vet, and they put her on meds to calm her down, also I would suggest using kongs when you leave, also raw marrow bones when possible {cuz the have to be eaten outside, freeze them so it takes longer to get the marrow out, also I make sure they have as much meat on them as possible {make sure you feed them RAW} The marrow bones seem to put all of my dogs in a mellow mood, they just love them so much. Don't forget plenty of exercise, we bought a springer bike attachment for each of our mountain bikes to run the dogs, we all have a blast with that. Heres an article on seperation anxiety.
http://www.metpet.com/Reference/Dogs...ty_in_dogs.htm