Treating Separation Anxiety in any dog is very tough, and I applaud your desire to fix the problem rather than just simply put the dog down, or get rid of him. The problem develops for three main reasons.
1) The most common is the dog fears you will never return. This is especially common in adopted and rescued dogs. When I got my Cutler, he had already passed through 3 owners before me (he is only 8 months old). In this case, the easiest solution is desensitization. Try leaving the dog in your bedroom with the door shut for a minute or so – if he whines or cries, ignore it. Go inside after the few minutes and give him an amazing treat, like steak or chicken. Once you can do this for several minutes, move up in time.
2) Another common cause is lack of leadership. In some cases separation anxiety is caused by a dog who does not want a pack leadership position stepping up into one. In nature the pack leader is the one who leaves, he is not left, that is why he gets destructive while you are gone. Out of panic.
3) Built up energy is the final common cause. Sometimes, you can solve separation anxiety by merely talking your dog for a 45 minute walk before you leave.
Until you’ve figured out the cause, you have to manage the problem.
Dog proof your home, use Fooey, and give plenty of durable toys. Frozen Kong Extremes with Peanut Butter in them are a great option. You could also look at the everlasting treat ball. Leave plenty of other toys they can play with.
Also, vary your routine before leaving. One morning brush your teeth last, the next brush them first, so on.
The most important and most difficult is to follow the no talk, no touch rule. 20 minutes prior to leaving, cut off all touch and talk with your dog. Do this when you get home as well, you want it to appear “business as usual” rather than making a big deal out of it.
Good luck 🙂