dog constantly licking furniture & carpets

Question
What mineral or vitamin (if any at all) is a dog missing in his diet when he is constantly licking furniture to carpets all the time? he has plently of play and dhew toys but when he is on the couch with me he is constantly licking it or if I make him get down then he starts licking the rug!!!!   HELP!!!!!

Answer
My dog does the same,and my vet has said there is no medical reason for it-it's just a bad habit some dogs get

What I have done for furniture I use something called 'bitter apple' and it makes whatever they are licking/chewing taste terrible-and it can be bought at a petstore and if you can't find that name brand just ask the staff for something that is similar

My dog is 10 and still lick a lot,but has mostly grown out of it-and a lot of dogs seem to grow out of it on there own,so they may cure themselves