So Beau is just shy of 5 months now and I've been noticing when he runs or walks his back legs are straight and don't bend. I played with his legs bending all the joints and he doesn't show any discomfort or pain. When he runs really fast it kinda looks funny because his front legs are doing all the work. Is this normal? I'm not sure and I'm a little worried since they say most large breeds develope hip and joint problems.