Ever have one of those mornings where everything seems to go awry? You wake up late because you forgot to set the alarm. The coffee maker explodes. You can't find your keys, etc. The day progresses and hopefully you've worked your way through the madness. Then, when you arrive home, you find your dog sitting in a pile of fabric that was once your favorite pair of shoes. Well, I can't explain why your coffee maker exploded or why it is that you can't seem to remember to set your alarm (shame on you! how old are you again?) but I can explain why Rover decided to have a leathery lunch.
Dogs aren't the mind readers we want them to be but they do pick up on moods. They do it by reading your body language, by smelling you, and listening to the quality of your voice. You can't hide very much from them in the way of emotions because that is the only way they know how to communicate with you. If you are anxious, frantic, angry, sick, or nervously excited, your dog absorbs this. He thinks "My owner is anxious so there must be a reason to be anxious and the worst part is....I don't even know what the threat is!" You left in a frenzy this morning and now he's home alone in the same mood. You eventually work out your anxiety but you are his whole world and he's home alone and filled to the brim with anxiety. He's gotta release that tension and what better way then by chewing on something.
This is one thing that dogs have over us humans. We tend to bottle things up and "deal with it." They know they have to let it out. Chewing is calming to them and without access to the outside world during the day, it's one of the only tools they have to make themselves comfortable again.
We can't be on point all the time but actively work to start calming ourselves to help our dogs when we need to. If you are in a situation in which your dog usually acts out, then take your time and relax first. Don't proceed until you feel you are in control of the situation. If you have a reactive dog and you're out for a walk, stop around the corner before you get to the yard that has the rabid German Shepherd and do some deep breathing. Put slack in the leash. Give that yard a wide berth and try casually walking by. It could make a huge difference.