Hi Greg,
This is a great question, and one I can relate to personally. Chewing is a natural behavior for dogs, and generally, they have the most desire to chew as young puppies and this wanes with age. The problem is that they often do not select the most appropriate items to chew. This can lead to dangerous gastrointestinal obstructions and also ruins your belongings! Avoiding access to these items is probably the easiest, short-term solution, but I do have some other thoughts for you to consider.
You mentioned that your dog does this chewing when you leave. This is a big “red flag” to me that there is an anxiety component, which goes beyond normal chewing behavior. Perhaps he is using the chewing as a way to soothe or calm himself while you are away. Something that I find personally helpful for this problem is crate training. Contrary to popular belief, it should never be used to punish a dog for doing something wrong. Instead, it should be treated like safe space where he can relax. I like to think of it as my dog’s personal den area, where he can go if he feels like he needs to take a break. If he is not used to being confined, it will take some time and patience. Start by having him in the crate for short periods (5-10 minutes at first) several times a day without leaving the house, and reward generously with treats.
Another thing that can be very for a dog that chews everything is providing a distraction. This would be some type of toy that can be filled with peanut butter, processed cheese, treats, etc. Please test out the toy before leaving your dog unattended to ensure he does not ingest pieces of it. There are a variety of these types of toys available at most pet stores.
Seeking the assistance of a professional dog trainer is another suggestion I often recommend. They will be able to work with you and your dog on techniques to reduce his anxiety while you are away. The final suggestion I have would be to consult with your veterinarian to see if supplements or medications may be helpful. There are many products available that can help with mild to severe cases of anxiety and behavioral problems in dogs. Best results are always achieved when used in conjunction with training.
I hope this helps!
Dr. Kim Hester