It is completely normal for young dogs, and puppies to chew on whatever they can get their paws on. In some cases it is a way for them to relieve pain caused by new teeth coming in as they mature, and is beneficial for your puppy to chew on things as they are teething, in this case, you will want to give your dog something to chew on that is safe such as a Bully Stick.
For older, or fully grown dogs it is a way for them to keep their teeth healthy, and their jaws strong. Chewing can also be used as a way for dogs to relax, and stay busy however in some cases it can be seen as a sign of distress.
Lack of exercise: Dogs who are not stimulated on a daily basis, or who do not receive enough exercise to sufficiently stimulate them will often begin to compulsively chew on things as a way to combat their boredom. If you notice that your dog is starting to chew on things more than normal, try taking them on walks with you or to the dog park to try and get them more exercise.
Separation Anxiety: Sometimes dogs chew to relieve stress related to separation anxiety, a good way to tell if your dog is chewing due to separation anxiety is that they will typically chew on things when you are away. For instance, you may find that when you come home they have chewed on your favorite pair of shoes, but when you are with them they almost never chew on your items in a destructive manner. The best way to deal with this is to make changes in how your dog views you leaving, check out our in-depth blog in separation anxiety.
Hunger: Sometimes it can be as simple as your dog not receiving enough food, so in an attempt to get more nutrients they will start to eat at whatever appears appetizing. Typically in this behavior, you will notice that they will only chew on items that are related to food in one way or the other. For example their food bowl, or leftover Tupperware.
These are often the main causes of unhealthy and destructive chewing habits in dogs. However, you may find that even after you make these changes, that your furry loved one still has a habit of chewing whatever they can. At this point, it is suggested to work with your dog, by supplying them with the proper tools such as a bully stick.