One thing the vet told me about Lexy the other week is that when they have a struggle of some kind, like Lexy does (arthritis in her hips and stiffness from her knee injury and surgeries), they have learned responses. Caroline thinks that Lexy has learned that she needed to limp to avoid pain, not put weight on her leg, so even when she's not feeling pain she limps anyway since she knows to avoid pain like that. She has the most amazing muscle tone on that leg now after having none after her three surgeries and cage rest, that Caroline thinks the Cortaflex helps keep the stiffness at bay, and that most times the limp is forced.
Then again, I have to believe a little of this, as Lexy will fake a limp when she wants attention, yet when she thinks I'm not looking, the limp is barely noticeable