There are various reasons your dog may decide he needs to eat your favorite shoes or dig at the front door suddenly. While the reason may not matter while you are assessing the damage, if this is a new development, you want to understand the reason so you can quickly put a stop to the behavior.
The most common reason dogs develop sudden destructive tendencies is due to stress. This may be a one-off situation, such as if a delivery person rings the doorbell, upsetting your dog, or it may be a gradual development, with the dog becoming insecure about being left alone, and chewing, digging or otherwise using physical activity to ease his anxiety. You may be able to lessen his response to one-off episodes by exposing your dog to a variety of sights and sounds so he is less likely to become upset at strange noises. If your dog develops anxiety from being left alone, make several lifestyle choices to help lessen the issue. Make sure your dog gets plenty of exercise, both before and after you leave the home, try leaving him alone for shorter periods of time and, if the problem seems severe, talk to your veterinarian about anti-anxiety medications.
Maybe you let your dog chew on your fingers in the evening while you are playing, or let him play a little tug-of-war with your sock as you take it off. These can seem like fun, innocent games, but if your dog develops the habit of chewing and playing with things that are not his toys, you may quickly find that he has trouble stopping while you are away. Make sure he has several toys of various textures, and don't allow him to play with anything else.
You may think your dog is done teething, but not necessarily. Dogs can experience intermittent teething pain until they are two years old. When this pain hits, they will look for anything to chew. If his favorite chew toy isn't available, he will start on the baseboard, chair leg or anything else that is handy.
Has anything changed in your dog's lifestyle recently? Are you working longer hours? Has the weather kept you in more than usual? Changes that you don't really notice can leave your dog feeling lonely and bored, which can lead to destructive behavior. If you think boredom may be the problem, make time to play with your dog before you leave the house. Choose a high energy game, such as fetch, or a brisk walk, so he is ready to flop down for a nap when you leave.
There may be other, less obvious reasons that your dog has suddenly become destructive. He may view the attention he receives when he makes a mess as a reward, he may be hearing things outside, such as children playing, that he wants to join in on, or he may hear pests or rodents in the walls or under the floor, and he thinks he's helping out by doing a little hunting. Regardless of the reason your dog is feeling destructive, you can be confident he is not doing it to make you mad, or to retaliate for being left alone.