Most dogs lick things just as a way of feeling out their world. If your pooch can't seem to keep his tongue off the furniture, though, his compulsive licking could indicate a problem. Don't settle for a soggy couch and an anxious pooch -- get him the help he needs.
Treat your furniture with a licking-deterrent spray. These sprays, available at most pet supply stores, usually leave behind a bitter taste that discourages licking. Follow the instructions on the package, as these sprays generally require continuous application.
Take your dog to a veterinarian just to make sure that there aren't neurological issues at work. A dog exhibiting compulsive behaviors, like constant furniture licking, may be suffering from a neurological or even an emotional issue. For example, dogs with nervous anxiety may find comfort in licking the furniture -- a mood-altering prescription can quell your pooch's stress.
Exercise your dog. When a dog acts in this way, it could be the result of boredom and excess energy. Make sure that you're giving your dog adequate playtime and walking time every day to burn off energy and stimulate his mind. Lack of attention and exercise is a common cause of the anxiety that may be driving your dog to work out his tongue on the loveseat.