This happens due to iron deficiency. Many pet owners mistakes this condition with worms and gives repeated deworming drugs , but instead of cure  , the condition becomes worse . Therefore, please give any good iron tonic, such as Pet RBC syrup . Also please do not keep your dog alone for more than two hours , this causes anxiety and may aggravate the behaviour.

The first thing we need to do is identify why he is doing this. There are a few reasons why dogs do these kinds of things. 1) They may have nutritional deficiency, which needs regular deworming and balanced food 2) Behavior issue, which needs proper training for the pet.

They may eat unncessary items because of mineral deficiencies , wormburden, Enzymatic Deficiencies..They can be destructive because of Boredom,lack of Exercise..so try to find out the exact reason and work to resolve it..

Make sure your pet is dewormed and is being supplemented well. Puppies tend to do this because of teething. Provide carrots , celery etc to chew. Kindly engage him in exercise, playtime and provide ample chewing options.