Licking the air, their lips, their paws, objects for no reason is an anxious behavior--especially if the dog is incessant about it. This applies to licking people too. It's probably further evidence that the dog is seeking reassurance.
My parents' 10 year old female Yorkie is a very anxious and shy dog. It's like she can't sit still. If she's sitting on the couch she'll lick the couch. We say "no lick" so she stops, but then after awhile she starts licking and chewing her feet. If a person is sitting with her on the couch she'll try and lick the person incessantly, until we gently say "no lick" and shake our heads. She has learned that she gets praise when she stops licking. But with her, too much attention just makes her more nervous!
She does this licking when she doesn't know what to do with herself. Giving her some direction, and an outlet for that anxiety, seems to help her. We'll take her in the backyard and play with her with lots of praise. We'll take her on a walk, with us leading so she feels secure, and praise her during the walk. We also interrupt her licking by having her do some tricks to earn treats and praise.
Once she is reminded that she is a good girl and that we are there to lead her, to be her alpha dog, she feels much better. She'll settle down and take a nap or chew on a bone instead of licking. Sometimes just giving her a bone to chew on instead of licking whatever she's obsessed with will solve the problem. Making sure she gets plenty of exercise also prevents her anxiety from building up.
Try addressing the licking issue as an anxiety issue and see if that helps. |