I just moved into a new house yesterday, and unlike my last apartment this one has a second story. That means my chubby little shih tzu has stairs to climb for the first time in her life. At first I thought this was good and might help her shed a couple of those extra pounds, but my mom is worried that it'll "ruin her legs" like it did her boston terrier when she was my age. She suggests that I carry her up and down the stairs every time I go. For obvious reasons, I'd rather not do that, but I will if they pose a real risk to her health. What do you guys think?