Separation anxiety is not fun for both the dog and the humans. It is important not to ignore it, but to find a solution for your both own sanity and your dog's own safety and mental well-being.
Remember that he's not choosing to do it out of spite or malice - he is panicked about his own survival without you, his pack leader, there to protect him.
There is no one solution for all dogs. It will take trial and error as well as time, but peace can be accomplished. You also need to give each attempt proper time to prove failure or success. Do not throw in the towel on one method after just one day of not working. Give the method one week before deciding how to proceed.
Crating vs Free Roam: So many people dislike crating their dog; however did you ever think that the confinement of the crate may be just what your dog needs to feel secure? Lots of open space and empty rooms can be scary for some dogs.
On the flip side we do not want the dog chewing on wire just to escape with the potential of hurting himself. Plastic crates are preferred over wire crates for dogs with the ability to chew or try to escape.
If currently crating, trial short period letting him free roam with all doors closed limiting access to the whole house.
A Friend: Many dogs find comfort having someone around, human or dog. To determine if a friend is what your dog needs before adopting, offer to babysit/borrow a dog for a few days.
If you have multiple dogs already in the home make sure that everyone can see each other. That means confine them to one room. For example: one dog is crated and the other free roams. The crate is in the living room. Close all bedroom and bathroom doors and gate off the stairs. This forces the free roaming dog to stay in the same room as the crated dog so he is always in sight.
Departure from home: Determine what actions you perform when departing the house trigger your dog to show signs of stress. Modify those actions: consider changing up your routine for departure, make sure your departure is not a big deal to the dog, and create a diversion such as a toy or treat that will keep his attention until you are out the door.
Medication: Medication should be the last straw. It should also be used to offer calmness for your dog, not to put him out while you are gone. More people are using CBD oils with great success. As of now MABTR has yet to use it. Note that quality will vary by brand.
I strongly recommend to do your homework on options and reach out to others that have used specific drugs. In most cases once you start, you may not be able to stop if the dog becomes dependent in order to be calm when you are away. Also note that as with any drug it alters the way the dog normally behaves. A stressed dog may react differently/not give warnings the same way they did when not drugged.
Here are five tips to help ease separation anxiety:
1. Before you leave the house, take your dog for a walk.
2. No touch, no talk, no eye contact. Make leaving non excitable.
3. Say goodbye to your dog long before you leave.
4. Stay calm and assertive!
5. Start out small by leaving your dog alone for just five minutes. He wants to know you are returning
6. Leave your dog with a good audiobook.