Q:  My older dog, Dixie, a white Boxer, has always had an obsession with licking. She is 4 years old now and has taught our 1-year-old Boston Terrier the same habit. My husband and I don't mind a little licking, but she really takes it to a whole new level. She is very well trained and a very well-behaved dog, but this is something we have always struggled with. How do we teach her to tone down the licking?

A:  Although Dixie's licking strikes you as an obsession, you don't mention the adverse consequences I might expect in a dog with Canine Compulsive Disorder (CCD). For example, dogs with this condition may lick their paws until the flesh is raw and even until the bone is exposed. Or they may lick some object long enough to wear away the surface. I'm going to guess, then, that what Dixie licks so much is you, and that the behavior doesn't reflect CCD but rather has been reinforced somehow. I'll further guess that the reinforcer for Dixie's licking is attention — that when Dixie licks you, you respond to her in some way. Perhaps you pet her, push her away, reprimand her, or some combination of these. Whether attention is pleasant or unpleasant, it's still attention. It will keep a behavior going basically forever, because dogs crave attention from their social partners — us.

Your Boston may have learned to lick by the mechanism called "local enhancement." Dog A finds something interesting to do at a particular spot. Dog B notices and trots over to check out the same spot. What's so interesting over there? Dog B investigates. Maybe he experiments with a sniff and a lick. Attention is paid. Hey presto! Another licker is born.