Whats wrong with a 3 foot vert for a dog? My 2 smaller labs (60 and 85 pounds) both have about that.
Anyway - be careful Blue, I assume you have ice and snow in and around the yard? My 3 yr old took that spill at the park this summer on a slip (and I worry all winter) and tore ligaments in her leg....might want to get it checked out. Even a slight tear needs attention.